JP2018140488A - Repair method and member for repair of fatigue crack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a repair method for preventing crack reoccurrence from a hole end part by suppressing stress fluctuation width of the hole end part of a stop hole provided at a tip part of a fatigue crack.SOLUTION: A repair method of a fatigue crack includes: a step 1 for providing a stop hole 3 at a tip part of a fatigue crack 2 with respect to the fatigue crack 2 that occurs in a structure and/or providing a wedge hole 7 on a path other than a base part and the tip part of the fatigue crack; a step 2 for fitting wedge means 4 having a variable wedge load into the stop hole 3 and/or the wedge hole 7; and a step 3 for applying the wedge load for suppressing the stress fluctuation width of the structure of a hole end part of the stop hole 3 or the tip part of the fatigue crack 2.SELECTED DRAWING: Figure 13

Description

  The present invention relates to a method for repairing fatigue cracks generated in various structures such as ships, offshore structures, bridges, roads, vehicles, airplanes, and transportation / machine tools, and a repair member used therefor.

When fatigue cracks are found in metal structures such as ships, offshore structures, bridges, etc., it is necessary to take appropriate measures to prevent the cracks from continuing to develop and lead to serious damage accidents. .
However, it is often difficult to take extensive and permanent measures in a structure that is in operation or in service. Especially in areas where work involving fire such as welding and gouging is prohibited, temporary measures that are easy to install are taken for the time being and permanent measures such as the next entry or large-scale repair are possible. It is a realistic way to deal with the situation while watching the progress.
The most commonly used emergency measure is to reduce the stress concentration by providing a through-drilled hole (stop hole) at the crack tip, but if the crack is long or a sufficient hole diameter cannot be secured For example, cracks often recur from stop holes.

  In order to prevent cracks from recurring from the stop hole, Non-Patent Documents 1 and 2 disclose a method of tightening the stop hole with a high-strength bolt and nut and reinforcing it by frictional force. A method of closing the crack by hitting the base metal near the surface of the crack with an air tool with a flat chisel (ICR treatment) is used for reinforcing the stop hole. It has been shown to have sex.

  Further, in Patent Document 1, by providing a plurality of asymmetric holes on the crack propagation path and inserting and fixing an insertion member processed into a shape matching the hole, the opening of the crack due to an external load is formed. Techniques to suppress and prevent crack growth have been presented.

  Further, in Patent Document 2, in a fatigue crack growth suppressing method for suppressing the growth of a fatigue crack generated in a structure, the structure in which the fatigue crack is generated acts on the fatigue crack during the operation of the structure. By holding in a state where the maximum stress is applied, a fatigue crack is opened, and then the opening of the crack is opened in the opening to maintain the opening width of the fatigue crack as it is after the maximum stress is removed. Techniques for inserting width retainers have been presented.

  Further, Patent Document 3 proposes a technique in which a crack is drilled at the tip of a crack and a radial pressure is applied to the hole by a pressure load jig such as a taper pin.

JP-A-2006-199846 JP 2010-275707 A JP-A-4-20839

Takeshi Mori, “Repairing Fatigue Cracks by Bolting Stop Holes”, Journal of Structural Engineering, Japan Society of Civil Engineers, Vol.35A, p.969-976, March 1989 Chiaki Miki, 2 others, “Repair and stress improvement measures for fatigue cracks in gusset joints by stop holes”, Proceedings of Japan Society of Civil Engineers A1 (Structure and Earthquake Engineering), Japan Society of Civil Engineers, Vol.67, No .2, p.283-293, 2011. Risa Matsumoto, 4 others, “Improvement effect on fatigue strength of stop holes by crack closure”, Steel Structures, Japan Steel Structure Association, Vol. 21, No. 83, September 2014

However, the methods of Non-Patent Documents 1 and 2 have a problem that it is difficult to apply to a crack that propagates along the weld line and a location that cannot access the back side of the plate.
In addition, the method of Non-Patent Document 3 has a problem that it takes time and labor since it is necessary to perform vibration construction at a processing speed of about 10 to 20 cm / min multiple times for a single crack, and the plate thickness is penetrated. In the case of such a long crack, there is a problem that it is difficult to apply to a place where the back side of the plate cannot be accessed, as in the methods of Non-Patent Documents 1 and 2. Furthermore, since the crack closing action by plastic deformation of the struck base metal is used, there is a certain upper limit on the magnitude (amplitude) of repeated external loads that can be expected to improve fatigue strength after repair. There is also.

  In addition, it is unclear how much the invention described in Patent Document 1 actually has a progress prevention effect. Furthermore, there is an application problem that considerable time and labor are required to accurately process a plurality of holes having a relatively complicated shape including a curved surface on site.

  In the invention described in Patent Document 2, in general, the magnitude of the stress acting during the operation of the structure is probabilistically distributed, and it is not easy to correctly estimate the value of the maximum stress. Even if it can be estimated, there is an application problem that in many cases it is extremely difficult to keep the crack open by operating it, particularly in large structures.

  In addition, the invention described in Patent Document 3 does not use a pressure load jig such as a taper pin to be inserted into the hole, which has a variable wedge load after applying an internal pressure, and when an excessive load is applied after the repair is completed. There is a possibility that the pressure load jig will be loosened, shifted or detached excessively.

  Accordingly, the present invention provides a repair method for preventing the crack recurrence from the hole end by suppressing the stress fluctuation width at the hole end of the stop hole provided at the tip of the fatigue crack, and a repair member used in the repair method. The purpose is to do.

In the fatigue crack repairing method according to claim 1, a stop hole is provided at the tip of the fatigue crack with respect to the fatigue crack generated in the structure and / or on a path other than the base and tip of the fatigue crack. Step 1 for providing a wedge hole, Step 2 for fitting a wedge means with variable wedge load into the stop hole and / or wedge hole, and suppressing the stress fluctuation width of the structure at the hole end of the stop hole or the tip of the fatigue crack And a step 3 for applying a wedge load.
According to the first aspect of the present invention, the structure of the hole end portion of the stop hole or the tip portion of the fatigue crack is obtained by applying the wedge load by fitting the wedge means to at least one of the stop hole or the wedge hole. It is possible to suppress the stress fluctuation width of the crack and prevent crack recurrence from the structure at the hole end or the tip of the fatigue crack.
Further, since the wedge load of the wedge means is variable, the wedge load can be changed and acted on at least one of the stop hole and the wedge hole.
It should be noted that the wedge means includes all structures that can change the load substantially with displacement even if the shape is not tapered.

The present invention according to claim 2 further includes step 4 of adjusting the wedge load in order to follow the opening displacement of the hole portion of the stop hole and / or the opening displacement of the hole portion of the wedge hole and prevent loosening of the wedge means. It is characterized by that.
According to the second aspect of the present invention, the stress of the structure at the hole end portion of the stop hole or the tip end portion of the fatigue crack is prevented by preventing the inserted wedge means from loosening with time, shifting or coming off due to the loosening. The fluctuation suppressing effect can be maintained.
In addition, if the fitted wedge means is allowed to loosen to some extent and prevents excessive loosening over time, displacement or detachment due to excessive loosening, etc., the actual structure will prevent any looseness of the wedge means. Thus, it is possible to prevent the wedge means or the base material from buckling or plastic deformation that may occur when the opening displacement is completely followed.

The invention according to claim 3 is characterized in that the wedge load is adjusted within a range not exceeding the maximum value of the stress acting on the structure at the hole end of the stop hole or the tip of the fatigue crack.
According to the third aspect of the present invention, it is possible to prevent the wedge load from causing the crack recurrence.

The present invention according to claim 4 is characterized in that the maximum value of stress is obtained by actual measurement and / or simulation.
According to the fourth aspect of the present invention, the adjustment range of the wedge load can be made more accurate.

The present invention according to claim 5 is characterized in that the maximum value of the stress is obtained based on the maximum value of the opening displacement of the hole portion of the stop hole and / or the maximum value of the opening displacement of the hole portion of the wedge hole. .
According to the present invention described in claim 5, the adjustment range of the wedge load can be made more accurate.

The present invention according to claim 6 is characterized in that the adjustment of the wedge load is automatically performed by using the wedge means.
According to the present invention described in claim 6, since the wedge means can be automatically adjusted following the opening displacement of the hole due to excessive load and the loosening of the wedge means can be surely prevented, the maximum load during operation can be reduced. There is no need to estimate and hold it under load, and an appropriate wedge load is automatically applied according to the actual working load to prevent crack recurrence from the structure at the hole end or fatigue crack tip. Can be prevented.

The present invention according to claim 7 is characterized in that the wedge means is cooled and fitted into the stop hole and / or the wedge hole to apply a wedge load.
According to the present invention described in claim 7, fatigue cracks can be repaired easily and effectively.

The present invention according to claim 8 is characterized in that steps 1 to 3 are performed from one side of the structure.
According to the eighth aspect of the present invention, a repair work can be performed even when the work having fatigue cracks can be performed only from either the front side or the back side.

According to a ninth aspect of the present invention, there is provided a member for repairing a fatigue crack, comprising a wedge means and an automatic adjusting means for automatically adjusting a wedge load of the wedge means.
According to the ninth aspect of the present invention, the crack from the structure at the hole end or the tip of the fatigue crack is suppressed by suppressing the stress fluctuation width of the structure at the hole end of the stop hole or the tip of the fatigue crack. Repair that has the function to prevent recurrence and the function to automatically adjust the rusting means following the opening displacement of the hole due to excessive load, and to prevent the wedge means from loosening over time, and the displacement and detachment due to loosening. A member can be provided.
In addition, in the case of an automatic adjustment means that allows a certain degree of looseness of the fitted wedge means and prevents excessive looseness over time, displacement and detachment due to excessive looseness, etc. It is possible to prevent the wedge means or the base material from buckling or plastic deformation, etc., which can occur when the opening is completely followed by the displacement of the opening.

According to a tenth aspect of the present invention, the wedge means has a screw mechanism.
According to the tenth aspect of the present invention, the length of the wedge means and the wedge load can be made variable by utilizing the screw mechanism.

The present invention according to claim 11 is the first bolt shaft that is threaded, the second bolt shaft that is threaded in the opposite direction to the first bolt shaft, and the rotation that fits the first bolt shaft and the second bolt shaft. The screw mechanism is composed of a nut that expands and contracts the first bolt shaft and the second bolt shaft, and the automatic adjustment means is composed of a torque load member that applies torque to the nut and a load mechanism that applies load to the torque load member. Features.
According to the eleventh aspect of the present invention, the wedge means and the automatic adjustment means can be configured simply.

The present invention according to claim 12 comprises a pantograph type mechanism composed of a plurality of link parts, a bolt mechanism that extends and contracts the pantograph type mechanism, a screw mechanism, a torque load member that applies torque to the bolt mechanism, and a torque load member The automatic adjustment means is composed of a loading mechanism that applies a load to the sway.
According to the present invention of the twelfth aspect, the wedge means and the automatic adjustment means can be configured simply.

The invention according to claim 13 is a first slope part having a slope, a second slope part having a slope that slides on the first slope part, and a first slope part that slides the second slope part. The screw mechanism is constituted by a bolt fitted to the bolt female screw formed on the bolt, and a torque load member for applying torque to the bolt and an automatic adjusting means are constituted by a loading mechanism for applying a load to the torque load member. To do.
According to the thirteenth aspect of the present invention, the wedge means and the automatic adjustment means can be configured simply.

According to a fourteenth aspect of the present invention, a first divided female screw component having a tapered female screw, a second divided female screw component having a tapered female screw, and a first divided female screw component and a second divided female screw component are sandwiched. A torque load member configured to form a screw mechanism from a taper bolt that spreads the first divided female screw part and the second divided female screw part outward by rotating in a direction penetrating into the tapered female screw part, and to apply torque to the taper bolt; The automatic adjustment means is composed of a loading mechanism that applies a load to the torque load member.
According to the fourteenth aspect of the present invention, the wedge means and the automatic adjustment means can be configured simply.

The present invention according to claim 15 is characterized in that the torque load member is constituted by an arm.
According to the present invention of the fifteenth aspect, torque can be applied by utilizing the rotation of the arm and the lever principle.

The present invention according to claim 16 is characterized in that the torque load member is constituted by a pulley.
According to the sixteenth aspect of the present invention, torque can be applied using the rotation of the pulley, and the applied torque can be easily made constant.

The present invention according to claim 17 is characterized in that the torque load member applies a substantially constant torque to the nut, the bolt mechanism, the bolt, or the taper bolt.
According to the seventeenth aspect of the present invention, the wedge load can be easily managed.

The present invention according to claim 18 is characterized in that the loading mechanism is constituted by an elastic body.
According to the eighteenth aspect of the present invention, a load can be applied to the torque load member using the elasticity of the loading mechanism.

The present invention according to claim 19 is characterized in that the loading mechanism is configured with a weight.
According to the nineteenth aspect of the present invention, a load can be applied to the torque load member using gravity.

The invention according to claim 20 is characterized in that the wedge means includes a drop prevention means for preventing the wedge means from dropping from the stop hole and / or the wedge hole.
According to the 20th aspect of the present invention, it is possible to prevent the wedge means from being accidentally dropped off.

The present invention according to claim 21 is characterized in that the drop-off preventing means is a hook-shaped portion provided in the wedge means for sandwiching the structure around the stop hole and / or the wedge hole.
According to the 21st aspect of the present invention, the wedge means can be prevented from being accidentally dropped by sandwiching the structure with the hook-shaped portion provided in the wedge means itself.

According to the method for repairing fatigue cracks of the present invention, a wedge structure is applied to at least one of the stop hole or the wedge hole to apply a wedge load, thereby providing a structure at the hole end of the stop hole or the tip of the fatigue crack. It is possible to suppress the stress fluctuation width of the crack, and to prevent the crack recurrence from the structure at the end of the hole or the tip of the fatigue crack.
Further, since the wedge load of the wedge means is variable, the wedge load can be changed and acted on at least one of the stop hole and the wedge hole.

Further, in the case of further comprising step 4 for adjusting the wedge load in order to prevent the loosening of the wedge means following the opening displacement of the hole portion of the stop hole and / or the opening displacement of the hole portion of the wedge hole, the wedge to be fitted is provided. It is possible to maintain the effect of suppressing the stress fluctuation of the structure at the hole end portion of the stop hole or the tip portion of the fatigue crack by preventing the means from loosening with time and from being displaced or detached due to the loosening.
In addition, if the fitted wedge means is allowed to loosen to some extent and prevents excessive loosening over time, displacement or detachment due to excessive loosening, etc., the actual structure will prevent any looseness of the wedge means. Thus, it is possible to prevent the wedge means or the base material from buckling or plastic deformation that may occur when the opening displacement is completely followed.

  In addition, when the wedge load is adjusted within the range below the maximum value of the stress acting on the structure at the hole end of the stop hole or the tip of the fatigue crack, the wedge load is prevented from causing crack recurrence. it can.

  Moreover, when the maximum value of stress is obtained by actual measurement and / or simulation, the adjustment range of the wedge load can be made more accurate.

  In addition, when the maximum value of stress is obtained based on the maximum value of the opening displacement of the hole of the stop hole and / or the maximum value of the opening displacement of the hole of the wedge hole, the adjustment range of the wedge load is more accurately determined. Can be.

  In addition, when the wedge load is automatically adjusted using the wedge means, the wedge means is automatically adjusted by following the opening displacement of the hole due to the excessive load to ensure the looseness of the wedge means. Therefore, it is not necessary to estimate the maximum load during operation and hold it under load, and automatically apply an appropriate wedge load according to the actual working load, It is possible to prevent a crack from recurring from the structure at the tip.

  Further, when the wedge means is cooled and fitted into the stop hole and / or the wedge hole, and a wedge load is applied, the fatigue crack can be repaired easily and effectively.

  In addition, when Step 1 to Step 3 are performed from one side of the structure, repair work is performed even if work can be performed only from either the front side or the back side of the structure where the fatigue crack has occurred. be able to.

According to the fatigue crack repairing member of the present invention, the stress fluctuation width of the structure at the hole end of the stop hole or the tip of the fatigue crack is suppressed, and the structure from the structure at the hole end or the fatigue crack tip is suppressed. It has a function to prevent the recurrence of cracks and a function to automatically adjust the rusting means following the opening displacement of the hole due to an excessive load, and to prevent the wedge means from loosening over time, displacement and detachment due to loosening, etc. A repair member can be provided.
In addition, in the case of an automatic adjustment means that allows a certain degree of looseness of the fitted wedge means and prevents excessive looseness over time, displacement and detachment due to excessive looseness, etc. It is possible to prevent the wedge means or the base material from buckling or plastic deformation, etc., which can occur when the opening is completely followed by the displacement of the opening.

  When the wedge means has a screw mechanism, the length of the wedge means and the wedge load can be made variable by using the screw mechanism.

  In addition, the first bolt shaft that is threaded, the second bolt shaft that is threaded in the direction opposite to the first bolt shaft, and the first bolt shaft and the second bolt shaft that are rotated by fitting with the first bolt shaft and the second bolt shaft. When the screw mechanism is composed of a nut that expands and contracts the bolt shaft, and the automatic adjustment means is composed of a torque load member that applies torque to the nut and a load mechanism that applies load to the torque load member, the wedge means and automatic adjustment A means can be made into a simple structure.

  Also, a screw mechanism is constituted by a pantograph type mechanism composed of a plurality of link parts, and a bolt mechanism that expands and contracts the pantograph type mechanism, a torque load member that applies torque to the bolt mechanism, and a loading mechanism that applies a load to the torque load member When the automatic adjustment means is configured from the above, the wedge means and the automatic adjustment means can be configured simply.

  In addition, a first slope part having a slope, a second slope part having a slope that slides on the first slope part, and a bolt female screw formed on the first slope part that slides the second slope part When the screw mechanism is constituted by the bolts to be fitted, and the automatic adjustment means is constituted by the torque load member for applying torque to the bolt and the load mechanism for applying a load to the torque load member, the wedge means and the automatic adjustment means are provided. A simple configuration can be obtained.

  In addition, the first divided female screw part having the tapered female screw, the second divided female screw part having the tapered female screw, and the tapered female screw part configured to be sandwiched between the first divided female screw part and the second divided female screw part The screw mechanism is composed of a taper bolt that spreads the first divided female screw part and the second divided female screw part outward by rotating in the penetration direction, a torque load member that applies torque to the taper bolt, and a load applied to the torque load member When the automatic adjustment means is configured from the loading mechanism, the wedge means and the automatic adjustment means can be configured simply.

  When the torque load member is configured with an arm, torque can be applied by utilizing the principle of rotation of the arm and the lever.

  When the torque load member is configured with a pulley, the torque can be applied by utilizing the rotation of the pulley, and the applied torque can be easily made constant.

  Further, when the torque load member applies a substantially constant torque to the nut, the bolt mechanism, the bolt, or the taper bolt, the management of the wedge load is facilitated.

  In addition, when the loading mechanism is configured with an elastic body, a load can be applied to the torque load member using the elasticity of the loading mechanism.

  Further, when the loading mechanism is configured with a weight, it is possible to apply a load to the torque load member using gravity.

  In addition, when the wedge means is provided with a drop prevention means for preventing the wedge means from falling out of the stop hole and / or the wedge hole, it is possible to prevent the wedge means from being accidentally dropped.

  In addition, when the drop-off preventing means is a hook-shaped part provided in the wedge means for sandwiching the structure around the stop hole and / or the wedge hole, the structure is sandwiched by the hook-shaped part provided in the wedge means itself. It is possible to prevent the wedge means from being accidentally dropped.

Schematic diagram showing a fatigue crack repair method and repair member according to the first embodiment of the present invention. A finite element model with wedge means fitted in a stop hole. Diagram showing the results of finite element analysis Diagram showing the results of finite element analysis Schematic diagram showing a fatigue crack repair method and repair member according to a second embodiment of the present invention. Schematic diagram showing a fatigue crack repair method and a repair member according to a third embodiment of the present invention. The schematic diagram which shows the repair method of the fatigue crack by 4th embodiment of this invention, and the member for repair Schematic diagram showing a fatigue crack repair method and repair member according to a fifth embodiment of the present invention. Schematic diagram showing a fatigue crack repair method and repair member according to a sixth embodiment of the present invention. Schematic diagram showing a fatigue crack repair method and a repair member according to a seventh embodiment of the present invention. Schematic diagram showing a fatigue crack repair method and repair member according to an eighth embodiment of the present invention. Schematic diagram showing a fatigue crack repair method and repair member according to a ninth embodiment of the present invention. Schematic diagram showing another example of automatic adjustment means according to the present invention. Schematic diagram showing still another example of the automatic adjustment means according to the present invention. Schematic diagram showing still another example of the automatic adjustment means according to the present invention. Schematic diagram showing an example of dropout prevention means according to the present invention Schematic diagram showing another example of dropout prevention means according to the present invention. Schematic diagram showing a fatigue crack repair method and a repair member according to a tenth embodiment of the present invention. The figure which shows the fluctuation width suppression effect of the hole edge part stress by this invention The figure which shows the flat plate test piece used for the test Diagram showing the wedge means used in the test Diagram showing the relationship between circular hole end strain and tensile load Diagram showing pulley used in testing Diagram showing the relationship between pulley rotation angle and tensile load Diagram showing the relationship between circular hole end strain and tensile load Diagram showing fatigue test results

  The fatigue crack repair method and repair member according to the embodiment of the present invention will be described below.

  FIG. 1 is a schematic view showing a fatigue crack repair method and a repair member according to a first embodiment of the present invention.

The fatigue crack repair method according to the present embodiment is as follows. First, a stop hole 3 is formed at the tip of the fatigue crack 2 with respect to the fatigue crack 2 generated in the base metal plate 1 of a structure such as a ship, an offshore structure or a bridge. Provided (step 1).
After step 1, the wedge means 4 having a variable wedge load is fitted into the stop hole 3 (step 2).

In this embodiment, the wedge means 4 that is a repair member has a screw mechanism 10. The screw mechanism 10 includes a bolt shaft 11 and a nut 12.
The bolt shaft 11 includes a first bolt shaft 11A and a second bolt shaft 11B. One end of the first bolt shaft 11A and the second bolt shaft 11B is threaded to form a groove. The threaded end of the first bolt shaft 11A is screwed to one side of the nut 12, and the threaded end of the second bolt shaft 11B is threaded to the other side of the nut 12. The shaft 11A and the second bolt shaft 11B are connected in series via a nut 12.
One end of the second bolt shaft 11B is threaded in the opposite direction to the first bolt shaft 11A. Further, the inner surface of the nut 12 is threaded in the direction opposite to the portion screwed to the first bolt shaft 11A and the second bolt shaft 11B. Accordingly, the first bolt shaft 11A and the second bolt shaft 11B are both pushed out of the nut 12 when the nut 12 is rotated in one direction, and are both drawn into the nut 12 when the nut 16 is rotated in the other direction. . With this structure, the wedge load applied to the hole end of the stop hole 3 is variable.
In step 2, the first bolt shaft 11 </ b> A and the second bolt shaft 11 </ b> B are fitted so that the other end opposite to the threaded one end is in contact with the hole end portion of the stop hole 3. At this time, as shown in FIG. 1, it is preferable that the wedge means 4 is disposed in the stop hole 3 so as to stand substantially perpendicular to the fatigue crack 2.

  After step 2, both the first bolt shaft 11 </ b> A and the second bolt shaft 11 </ b> B are rotated by applying the torque N <b> 1 in the direction in which both the first bolt shaft 11 </ b> A and the second bolt shaft 11 </ b> B are pushed out of the nut 12. The wedge load W is applied to the hole end of the stop hole 3 by being pushed by the bolt shaft 11 (step 3).

Here, the verification result of the stress fluctuation suppressing effect at the end portion of the stop hole hole by finite element analysis will be described. FIG. 2 is a finite element model when the wedge means is fitted in the stop hole, and FIGS. 3 and 4 are diagrams showing the results of finite element analysis.
The effect of suppressing stress fluctuation at the hole end when the stop hole 3 was reinforced by the wedge means 4 was verified by finite element analysis. For the analysis, general-purpose structural analysis software Marc Mentat (version 2015.0.0) was used. The analysis was a plane stress analysis, and a contact element was used for the fitting portion of the wedge means 4.
A finite element model when the wedge means 4 is fitted is shown in FIG. A 100 mm × 100 mm square steel plate (thickness 10 mm, Young's modulus 205.8 GPa) is provided with a slit that models a fatigue crack 2 and a stop hole 3 having a diameter of 20 mm. is there. The material of the wedge means 4 was steel as in the case of the plate, but the plate thickness was 20 mm in order to increase the rigidity.
In the analysis, the analysis was performed assuming that the right side of the model is constrained in the X direction with the symmetry plane, and one stop hole 3 is provided at each end of the slit. For convenience, the lower end portion of the wedge means 4 is fixed to the lower end portion of the stop hole 3, and contact elements for contact analysis are provided on the upper end portion of the wedge means 4 and the upper end portion of the stop hole 3. Anisotropy was given to the thermal expansion coefficient of the wedge means 4, and when the node temperature was raised, it was allowed to expand only in the Y direction, and the generation of the wedge load was simulated by thermal stress analysis. In the analysis, the Y-direction strain of 0.4% was generated by the thermal expansion of the wedge means 4. Moreover, as the tensile load in the Y direction applied to the steel plate, the load was applied so that a tensile stress of 60 MPa was generated on the upper and lower sides of the model.

The results of the finite element analysis are shown in FIGS. Of these, FIG. 3 shows the case without reinforcement by the wedge means 4, and FIG. 4 shows the case with reinforcement by the wedge means 4.
In the case of no reinforcement by the wedge means 4, when the tensile load is zero, the tensile stress in the hole end (Y direction) is zero as shown in FIG. 3A, and when the above-described tensile load (Y direction) is loaded on this. The tensile stress at the hole end is 693 MPa as shown in FIG. 3B, and this is the fluctuation width of the hole end tensile stress due to the tensile load as it is.
On the other hand, when reinforced by the wedge means 4, even when the tensile load is zero, the wedge load by the wedge means 4 acts on the hole as shown in FIG. A stress of 383 MPa is generated. If a tensile load is applied in this state, a tensile stress is generated at the hole end. However, since the initial stress by the wedge means 4 is released, the tensile stress at the hole end is 676 MPa as shown in FIG. The value is close to that shown in FIG. However, since the initial stress value when reinforced is 383 MPa as shown in FIG. 4A, the fluctuation width of the hole end tensile stress accompanying the tensile load loading is the difference between 676-383 = 293 MPa, and there is no reinforcement. Compared to 693 MPa in this case, it is found that the reduction is about 58%, which is greatly suppressed.
Therefore, by performing Step 1 to Step 3, it is possible to suppress the stress fluctuation width at the hole end portion of the stop hole 3 and prevent the crack from recurring from the hole end portion.

As shown in FIG. 1, the portion of the bolt shaft 11 that contacts the hole end of the stop hole 3, that is, the other end of the first bolt shaft 11A and the second bolt shaft 11B is the hole end of the stop hole 3. It is preferable to process it into a curved surface shape so as to match the shape. By processing in this way, it is possible to prevent the bolt shaft 11 from coming into close contact with the hole end portion of the stop hole 3 and the wedge means 4 from being displaced from the stop hole 3 or falling off.
Further, for example, the wedge means 4 has a shape from which the other end of the first bolt shaft 11 </ b> A and the second bolt shaft 11 </ b> B sandwiches the hole end portion of the stop hole 3 from both sides of the base material plate 1. It is preferable to provide a drop-off prevention means for preventing the shift and drop-out. As a result, a load in the direction of opening the fatigue crack 2 acts on the base metal plate 1, the stop hole 3 spreads in the load direction (vertical direction in FIG. 1), the wedge load W becomes zero, the bolt shaft 11 and the stop hole Even if the contact with the end of the hole 3 is loosened, it is possible to prevent the wedge means 4 from shifting or dropping off.
Further, since it is generally not easy to perform the work from the back side of the base material plate 1 due to access problems or the like, the installer can only perform the work of fitting the wedge means 4 into the stop hole 3 from the front side in Step 2. It is thought that there are many cases. When the work can be performed only from the front side, if the component part of the wedge means 4 is accidentally dropped to the opposite side (back side) of the base material plate 1, the dropped component part may not be recovered. In addition, dropping the component parts is dangerous. In order to avoid such a situation, before fitting the wedge means 4 into the stop hole 3, the components of the wedge means 4 are locked to the base material plate 1 using a wire or chain having sufficient strength. It is preferable to prevent the components from falling. The largest maximum component among the components of the wedge means 4 may be locked to the base material plate 1, and the other components may be locked to the maximum component. Here, the method of locking the wire or the chain to the base material plate 1 or the component is arbitrary, and it is passed through a hole opened in a place where there is no problem with stress, or a hook or screw for locking is separately provided. It may be locked by providing, or may be locked using a magnet when the base plate 1 or the component is a ferromagnetic material.

When an excessive load acts on the base material plate 1 and the opening displacement of the hole portion of the stop hole 3 becomes large, both the first bolt shaft 11A and the second bolt shaft 11B are pushed out from the nut 12 in the nut direction. By rotating 12, the wedge means 4 is extended to adjust the wedge load (step 4).
By adjusting the wedge load by following the opening displacement of the hole of the stop hole 3 in this way, the contact between the bolt shaft 11 and the stop hole 3 is prevented from excessively loosening, and the stop hole by the wedge means 4 is prevented. The effect of suppressing the stress fluctuation at the hole end 3 can be maintained.
In addition, it is preferable to adjust this wedge load in the range below the maximum value of the stress which acts on the hole edge part of the stop hole 3. FIG. Thereby, it can prevent that a wedge load causes a crack recurrence.
Further, it is preferable that the maximum value of stress is obtained by at least one of actual measurement or simulation or based on the maximum value of the opening displacement of the hole portion of the stop hole 3. Thereby, the adjustment range of the wedge load can be made more accurate.

  As described above, the fatigue crack repairing method and the repair member according to the first embodiment are capable of grasping the degree of load acting on the base material plate 1, and the degree of the load is the wedge load W applied in the present embodiment. This is particularly effective when it is predicted that the stress fluctuation width at the hole end of the stop hole 3 can be sufficiently suppressed.

  FIG. 5 is a schematic diagram showing a fatigue crack repair method and a repair member according to the second embodiment of the present invention. FIG. 5 (a) shows a state in which an excessive load is applied to the base material plate, and FIG. ) Shows a state in which the wedge means is extended following the deformation of the stop hole, and FIG. 5C shows a state in which the excessive load is unloaded. In addition, the same code | symbol is attached | subjected to the same functional member as embodiment mentioned above, and description is abbreviate | omitted.

The repair member in this embodiment is a wedge means 4 and an automatic adjustment means 5 having a screw mechanism 10.
The automatic adjustment means 5 includes a torque load member 21 that applies torque to the nut 12 and a loading mechanism 22 that applies a load to the torque load member 21.
In this embodiment, the torque load member 21 is an arm such as a wrench (spanner), and the loading mechanism 22 is a spring (coil spring) that is an elastic body. By configuring the torque load member 21 with an arm, torque can be applied to the nut 12 using the rotation of the arm and the lever principle. In addition, by configuring the loading mechanism 22 with an elastic body, a load can be applied to the torque load member 21 using the elasticity of the loading mechanism 22. In addition to the spring, rubber, an air cylinder, or the like can be used as the elastic body. Further, at one end of the torque load member 21, an engaging portion 21 </ b> A that engages with the nut 12 is provided.

  In the fatigue crack repair method according to the present embodiment, the stop hole 3 is provided at the tip of the fatigue crack 2 generated in the base metal plate 1 in the same manner as the fatigue crack repair method according to the first embodiment (step 1). The wedge means 4 is fitted into the hole 3 (step 2), and the nut 12 is rotated by applying torque N1 in the direction in which the first bolt shaft 11A and the second bolt shaft 11B are both pushed out of the nut 12, so that the stop hole 3 A wedge load W is applied to the hole end (step 3).

After step 3, the engaging portion 21A of the torque load member 21 is engaged with the nut 12. Thereby, the nut 12 and the torque load member 21 are connected. In addition, one end of the loading mechanism 22 is connected to the other end of the torque load member 21, and the other end of the loading mechanism 22 is connected to the base plate 1 or the fixed portion 6 such as a wall surface whose relative position with the base plate 1 does not change. Connect and hold the load mechanism 22 in a contracted state than the natural length. As a result, the load F acts on the torque load member 21, and the torque N2 in the direction in which both the first bolt shaft 11A and the second bolt shaft 11B are pushed out from the nut 12 is loaded.
Here, the torque N2 is much smaller than the torque N1 applied in step 3 (see FIG. 1), and the nut 12 is not rotated by the torque N2 in a state where a non-zero wedge load W is generated. To do.

An excessive load in the direction in which the fatigue crack 2 opens acts on the base metal plate 1 and the stop hole 3 extends greatly in the load direction, and the wedge load W applied to the hole end of the stop hole 3 in step 3 is increased. If a slight gap is generated between the bolt shaft 11 and the hole end of the stop hole 3 (FIG. 5A), the nut 12 is immediately rotated by the torque N2 applied in advance. The first bolt shaft 11A and the second bolt shaft 11B are pushed out from the nut 12 until the other ends of the first bolt shaft 11A and the second bolt shaft 11B come into contact with the hole ends of the stop hole 3 (FIG. 5B). ).
When the excessive load is unloaded, the shape of the stop hole 3 extending in the load direction tends to return to the original shape, whereas the nut 12 of the screw-type wedge member 10 does not rotate. The lengths of the first bolt shaft 11A and the second bolt shaft 11B remain in the extruded state shown in FIG. Therefore, as a result, a wedge load W ′ is generated at the hole end portion of the stop hole 3 at the time of complete unloading, but the first bolt shaft 11A and the second bolt shaft 11B are pushed out from the initial fitting (state of FIG. 1). Therefore, the value of the wedge load W ′ is larger than the wedge load W before the excessive load is applied (FIG. 5C).
Thus, according to the present embodiment, an excessive load that causes a gap between the bolt shaft 11 and the hole end of the stop hole 3 after the screw-type wedge member 10 is fitted in step 3 is subjected to the base plate. 1, the first bolt shaft 11 </ b> A and the second bolt shaft 11 </ b> B are pushed out from the nut 12 by the action of the torque load member 21 and the loading mechanism 22, and the other ends of the first bolt shaft 11 </ b> A and the second bolt shaft 11 </ b> B. When the contact with the hole end of the stop hole 3 is maintained and an excessive load of the same level is applied again after the unloading of the excessive load, an appropriate wedge load W ′ that does not cause loosening is automatically applied. Is done.
Thereby, when an excessive load acts on the base material plate 1 and the opening displacement of the hole portion of the stop hole 3 becomes large, the wedge means 4 is automatically adjusted to follow the opening displacement, and the wedge means 4 Therefore, it is not necessary to estimate the maximum load during operation and hold it under load, and after overload unloading, an appropriate wedge that is automatically adjusted according to the actual working load. A load can be applied to prevent a crack from recurring at the hole end.
The torque load member 21 preferably applies a substantially constant torque to the nut 12. By making the torque substantially constant, it becomes easy to manage the wedge load applied to the hole end portion of the stop hole 3.

Here, the pushing stroke characteristic of the loading mechanism 22 is a characteristic in which the nut 12 always follows and continues to apply a load F of a certain level or more, that is, the nut 12 continues to be loaded with a torque N2 of a certain level or more. Or an upper limit is set for the amount of rotation of the nut 12 and hence the push-out amount of the first bolt shaft 11A and the second bolt shaft 11B, so that the loading mechanism 22 moves by a certain stroke and the first bolt shaft 11A and When the second bolt shaft 11B is pushed out by a predetermined amount, the screw-type wedge member has a characteristic such that no more load is applied to the torque load member 21, that is, an overload action exceeding a predetermined upper limit. Whether the gap between the hole 10 and the hole end of the stop hole 3 is allowed to some extent depends on the magnitude of the external load applied to the part and the fatigue crack 2 Relationship between length, maximum wedge load generated when unloading external load and strength of screw type wedge member 10 and stop hole 3, and various characteristics of structure itself to be repaired (plate thickness, redundancy, buckling strength, etc.) It is preferable to select as appropriate while considering the above.
In addition, when the upper limit is set for the push-out amount of the first bolt shaft 11A and the second bolt shaft 11B, that is, a certain degree of loosening is allowed to prevent excessive loosening over time, displacement and disengagement due to excessive loosening, etc. In the case of the characteristic, it is a characteristic that the torque N2 of a certain level or more is continuously applied, and the screw type wedge member 10 or the base plate 1 that can be generated when the opening displacement is completely followed by preventing any looseness. Buckling or plastic deformation can be prevented.

  As described above, the fatigue crack repairing method and repair member according to the second embodiment have a simple structure, and the crack recurrence from the hole end portion is suppressed while suppressing the stress fluctuation width of the hole end portion of the stop hole 3. And the function of automatically adjusting the rusting means 4 following the opening displacement of the hole due to an excessive load, the degree of load acting on the base plate 1 is unknown or This is particularly effective when an excessive load is expected and the wedge load W applied in step 3 is not expected to sufficiently suppress the stress fluctuation width at the hole end.

  FIG. 6 is a schematic diagram showing a fatigue crack repair method and a repair member according to a third embodiment of the present invention. FIG. 6 (a) is a front view and FIG. 6 (b) is a right side view. In addition, the same code | symbol is attached | subjected to the same functional member as embodiment mentioned above, and description is abbreviate | omitted. Further, in order to make the structure easy to understand, a part of the structure is shown in FIG. 6B.

In the present embodiment, the wedge means 4 that is a repair member has a screw mechanism 100. The screw mechanism 100 includes a pantograph type mechanism 110 and a bolt mechanism 120 that expands and contracts the pantograph type mechanism 110.
The pantograph type mechanism 110 includes a pair of link parts 111 and a first pin part 112, a second pin part 113, a third pin part 114, and a fourth pin part 115 arranged between the pair of link parts 111. .
The first pin component 112 and the second pin component 113 are spaced apart in series in a center position in the longitudinal direction of the link component 111 in a direction orthogonal to the longitudinal direction of the link component 111. The third pin component 114 is disposed at one end of the link component 111, and the fourth pin component 115 is disposed at the other end of the link component 111.
The link component 111 includes a first plate 111A, a second plate 111B, a third plate 111C, and a fourth plate 111D.
One end of the first plate 111 </ b> A is connected to the third pin component 114, and the other end is connected to the first pin component 112. One end of the second plate 111B is connected to the first pin component 112, and the other end is connected to the fourth pin component 115. One end of the third plate 111C is connected to the third pin component 114, and the other end is connected to the second pin component 113. One end of the fourth plate 111D is connected to the second pin component 113, and the other end is connected to the fourth pin component 115.
The bolt mechanism 120 passes through a hole provided in the central portion of the first pin component 112 and is screwed into a female screw provided in the central portion of the second pin component 113.

  In the fatigue crack repair method according to the present embodiment, the stop hole 3 is provided at the tip of the fatigue crack 2 generated in the base metal plate 1 in the same manner as the fatigue crack repair method according to the first embodiment (step 1). The wedge means 4 having a variable wedge load is fitted into the hole 3 (step 2), and the wedge load is applied to the hole end of the stop hole 3 (step 3). In the following, the side where the builder is present is described as the front side and the opposite side as the back side with reference to the base plate 1.

  In step 2, the wedge means 4 is fitted into the stop hole 3 so that the first pin component 112 side is the front side, that is, the head of the bolt mechanism 120 is on the front side. The wedge means 4 is in a contracted state. At this time, as shown in FIG. 6, it is preferable that the wedge means 4 is arranged in the stop hole 3 so as to stand substantially perpendicular to the fatigue crack 2.

After step 2, when the torque N1 in the tightening direction is applied to the head of the bolt mechanism 120 and rotated, the center part of the link part 111 located on the front side and the link part 111 located on the back side are drawn toward each other, and accordingly The wedge means 4 extends in the longitudinal direction based on the same principle as a so-called pantograph jack, the hole end of the stop hole 3 is pushed by the third pin component 114 and the fourth pin component 115, and the wedge is formed at the hole end of the stop hole 3. A load W is applied (step 3).
Thereby, the stress fluctuation width of the hole edge part of the stop hole 3 can be suppressed, and the crack recurrence from a hole edge part can be prevented.
When an excessive load is applied to the base plate 1 and the opening displacement of the hole portion of the stop hole 3 is increased, the wedge means 4 is stretched to adjust the wedge load (step 4).

The third pin component 114 and the fourth pin component 115 are preferably processed into a shape and dimension in which the curvature of the end portion contacting the hole end portion of the stop hole 3 is substantially the same as the curvature of the stop hole 3. By processing in this way, the end curved surfaces of the third pin component 114 and the fourth pin component 115 are formed when the wedge means 4 is fitted into the target stop hole 3 with the bolt mechanism 120 lightly tightened. The wedge means 4 can be prevented from being displaced or dropped from the stop hole 3 because it is closely aligned with the hole end portion of the stop hole 3.
Further, for example, the wedge means 4 has a shape from the stop hole 3 such that the end portions of the third pin component 114 and the fourth pin component 115 are formed so as to sandwich the hole end portions of the stop hole 3 from both sides of the base plate 1. It is preferable to provide a drop-off prevention means for preventing the shift and drop-out. As a result, a load in the direction of opening the fatigue crack 2 acts on the base metal plate 1, the stop hole 3 spreads in the load direction (vertical direction in FIG. 6), the wedge load W becomes zero, and the pantograph mechanism and the stop hole 3 It is possible to prevent the wedge means 4 from being displaced or dropped even if the contact with is loosened.
Further, as described in the first embodiment, before the wedge means 4 is fitted into the stop hole 3, the base material plate 1 or the like is formed by using a wire, chain, magnet, or the like having sufficient strength for the components of the wedge means 4. It is effective to prevent the component parts from falling.

  As described above, the fatigue crack repairing method and the repair member according to the third embodiment are capable of grasping the degree of the load acting on the base material plate 1, and the degree of the load is the wedge load W applied in the present embodiment. This is particularly effective when it is predicted that the stress fluctuation width at the hole end of the stop hole 3 can be sufficiently suppressed.

  FIG. 7 is a schematic diagram showing a fatigue crack repair method and a repair member according to the fourth embodiment of the present invention. FIG. 7 (a) shows a state in which an excessive load is applied to the base material plate, and FIG. ) Shows a state in which the wedge means is extended following the deformation of the stop hole, and FIG. 7C shows a state in which the excessive load is unloaded. In addition, the same code | symbol is attached | subjected to the same functional member as embodiment mentioned above, and description is abbreviate | omitted.

The repair members in this embodiment are a wedge means 4 and an automatic adjustment means 5 having a screw mechanism 100.
The automatic adjustment means 5 includes a torque load member 131 that applies torque to the bolt mechanism 120 and a loading mechanism 132 that applies a load to the torque load member 131.
In this embodiment, the torque load member 131 is an arm such as a wrench (spanner), and the loading mechanism 132 is a weight suspended from a high-strength rope. By configuring the torque load member 131 with an arm, torque can be applied to the bolt mechanism 120 using the rotation of the arm and the lever principle. In addition, by configuring the loading mechanism 132 with a weight, it is possible to apply a load to the torque load member 131 using gravity. Note that an engagement portion 131 </ b> A that engages with the bolt mechanism 120 is provided at one end of the torque load member 131.

  In the fatigue crack repair method according to the present embodiment, a stop hole 3 is provided at the tip of the fatigue crack 2 generated in the base metal plate 1 in the same manner as the fatigue crack repair method according to the third embodiment (step 1). The wedge means 4 is fitted into the hole 3 (step 2), and the wedge means 4 is stretched by applying a torque N1 in the direction of tightening to the head of the bolt mechanism 120 to extend the wedge at the hole end portion of the stop hole 3. A load is applied (step 3).

After step 3, the engagement portion 131A of the torque load member 131 is engaged with the bolt mechanism 120. Thereby, the bolt mechanism 120 and the torque load member 131 are connected. In addition, the loading mechanism 132 is connected to the other end of the torque load member 131. As a result, the load F acts on the torque load member 131, and the bolt mechanism 120 is loaded with the torque N2 in the direction in which the wedge means 4 extends.
Here, the torque N2 is much smaller than the torque N1 applied in Step 3 (see FIG. 6), and the bolt mechanism 120 is not rotated by the torque N2 in a state where a non-zero wedge load W is generated. To do.

An excessive load in the direction in which the fatigue crack 2 opens acts on the base metal plate 1 and the stop hole 3 extends greatly in the load direction, and the wedge load W applied to the hole end of the stop hole 3 in step 3 is increased. In the case where a slight gap is generated between the third pin part 114 and the fourth pin part 115 and the stop hole 3 (FIG. 7A), the bolt N is immediately increased by the pre-loaded torque N2. The mechanism 120 rotates and the pantograph type mechanism 110 extends until the third pin part 114 and the fourth pin part 11 come into contact with the hole ends of the stop hole 3 (FIG. 7B).
When the excessive load is unloaded, the shape of the stop hole 3 extended by the excessive load tends to return to the original shape, whereas the bolt mechanism 120 does not rotate and the wedge means 4 The stretched state remains as shown in FIG. Therefore, as a result, a wedge load W ′ is generated at the hole end portion of the stop hole 3 at the time of complete unloading. However, since the wedge means 4 is extended more than at the time of initial fitting (state of FIG. 6), the wedge load W ′ is reduced. The value is larger than the wedge load W before the excessive load is applied (FIG. 7C).
Thus, according to the present embodiment, after the wedge means 4 is fitted in step 3, a gap is generated between the third pin part 114 and the fourth pin part 115 and the hole end of the stop hole 3. Even if an excessive load is applied to the base plate 1, the pantograph type mechanism 110 is extended by the action of the torque load member 131 and the loading mechanism 132, and the third pin part 114, the fourth pin part 115, and the hole end of the stop hole 3. Even when an excessive load of the same level is applied again after unloading the excessive load, an appropriate wedge load W ′ that does not cause loosening is automatically applied.
Thereby, when an excessive load acts on the base material plate 1 and the opening displacement of the hole portion of the stop hole 3 becomes large, the wedge means 4 is automatically adjusted to follow the opening displacement, and the wedge means 4 Therefore, it is not necessary to estimate the maximum load during operation and hold it under load, and after overload unloading, an appropriate wedge that is automatically adjusted according to the actual working load. A load can be applied to prevent a crack from recurring at the hole end.
Note that the torque load member 131 preferably applies a substantially constant torque to the bolt mechanism 120. By making the torque substantially constant, it becomes easy to manage the wedge load applied to the hole end portion of the stop hole 3.

Here, the stroke characteristic of the loading mechanism 132 is a characteristic that always follows the bolt mechanism 120 regardless of how much the bolt mechanism 120 rotates, that is, continuously applies a load F of a certain level or more, that is, loads the bolt mechanism 120 with a torque N2 of a certain level or more. If there is an upper limit on the amount of rotation of the bolt mechanism 120 and hence the extension amount of the link mechanism, and the loading mechanism 132 moves by a certain stroke and the pantograph type mechanism 110 is extended by a predetermined amount, Whether or not the characteristic is such that the load between the wedge means 4 and the hole end portion of the stop hole 3 is allowed to some extent at the time of excessive load action exceeding the predetermined upper limit. The size of the external load applied to the part, the length of the fatigue crack 2, the maximum wedge load generated when the external load is unloaded, the wedge means 4 and the strike Relationship of the intensity of Puhoru 3, properties of the structure itself as a target of repair (thickness, redundancy, suppositories, etc. column strength) while taking into consideration, it is preferable to select as appropriate.
In addition, when an upper limit is set for the amount of extension of the link mechanism, that is, when a certain degree of looseness is allowed and excessive loosening with time, and characteristics such as deviation or disengagement due to excessive loosening are set, a certain level or more To prevent the buckling or plastic deformation of the wedge means 4 or the base material plate 1 that can occur when the opening N is completely followed by the opening displacement. it can.

  As described above, the fatigue crack repairing method and repair member according to the fourth embodiment suppresses the hole end portion stress fluctuation width of the stop hole 3 while the repair member has a simple configuration, and the crack recurrence from the hole end portion. And the function of automatically adjusting the rusting means 4 following the opening displacement of the hole due to an excessive load, the degree of load acting on the base plate 1 is unknown or This is particularly effective when an excessive load is expected and the wedge load W applied in step 3 is not expected to sufficiently suppress the stress fluctuation width at the hole end.

  FIG. 8 is a schematic diagram showing a fatigue crack repair method and a repair member according to a fifth embodiment of the present invention. FIG. 8 (a) is a front view and FIG. 8 (b) is a right side view. In addition, the same code | symbol is attached | subjected to the same functional member as embodiment mentioned above, and description is abbreviate | omitted. Further, in order to make the structure easy to understand, a part of the structure is shown in FIG.

In this embodiment, the wedge means 4 that is a repair member has a screw mechanism 200. The screw mechanism 200 is screwed into a first slope part 210 in which a bolt female thread is formed, a second slope part 220 slidably abutting on the first slope part 210, and a bolt female thread of the first slope part 210. It is comprised with the bolt 230 which is.
The first slope component 210 is substantially L-shaped in a side view, and includes a parallel part 211 arranged in parallel to the base material plate 1 and a fitting part 212 inserted into the stop hole 3. The bolt female thread is formed in the parallel part 211. The contact surface of the fitting portion 212 with the second slope component 220 is a slope.
The second slope part 220 has a quadrangular shape, and the contact surface of the first slope part 210 with the fitting portion 212 is a slope. The slope angle of the slope of the second slope part 220 is the same as the slope angle of the slope of the first slope part 210, and both are in close contact. The angle of the slopes of the first slope part 210 and the second slope part 220 is smaller than 45 degrees.
The bolt female screw formed on the first slope component 210 passes through the parallel portion 211 of the first slope component 210, and the shaft portion of the bolt 230 is longer than the bolt female screw. Accordingly, the shaft portion of the bolt 230 screwed into the female screw thread passes through the parallel portion 211 of the first slope component 210, and the tip abuts against the second slope component 220 to bring the second slope component 220 into the stop hole 3. Can be pushed in. In the present embodiment, a hexagon socket head cap screw is used as the bolt 230, but the type of bolt that can be used is arbitrary and is not limited to a hexagon socket head cap screw.
Further, if there is a corner at the tip of the bolt 230 that contacts the second slope part 220, the second slope part 220 is likely to be slid or damaged, and the bolt 230 cannot be smoothly rotated. As shown in (b), the tip of the bolt 230 is preferably finished in a spherical or elliptical shape having an appropriate curvature.

  In the fatigue crack repair method according to the present embodiment, the stop hole 3 is provided at the tip of the fatigue crack 2 generated in the base metal plate 1 in the same manner as the fatigue crack repair method according to the first embodiment (step 1). The wedge means 4 having a variable wedge load is fitted into the hole 3 (step 2), and the wedge load is applied to the hole end of the stop hole 3 (step 3).

  In step 2, the first slope part 210 and the second slope part 220 are fitted into the stop hole 3. At this time, as shown in FIG. 8, it is preferable that the first slope component 210 is disposed in the stop hole 3 so as to stand substantially perpendicular to the fatigue crack 2.

After step 2, when torque N1 in the tightening direction is applied to the bolt 230 and rotated, the second slope part 220 is pushed against the tip of the shaft of the bolt 230 protruding from the bolt internal thread of the first slope part 210, and the first The slope component 210 and the second slope component 220 move in directions away from each other, but the contact surfaces of the both are slopes that form a fixed angle (less than 45 degrees) with respect to the movement direction. As a result, a drag force larger than the bolt axial force is generated on the inclined surface where both are in contact, and a wedge load W is applied to the hole end portion of the stop hole 3 in contact with the wedge means 4 as a reaction force (step 3).
Thereby, the stress fluctuation width of the hole edge part of the stop hole 3 can be suppressed, and the crack recurrence from a hole edge part can be prevented.
When an excessive load acts on the base material plate 1 and the opening displacement of the hole portion of the stop hole 3 becomes large, the wedge load is obtained by pushing the second slope part 220 with the bolt 230 and extending the wedge means 4. Is adjusted (step 4).

Here, in order for the wedge means 4 to function stably over a long period of time, it is preferable that the second slope component 220 does not slide out due to the wedge load W even if there is no support by the bolt 230. Must satisfy the condition of the following formula (1).

[Formula 1]
tanα <μ (1)

However, μ is the maximum coefficient of static friction between the first slope part 210 and the second slope part 220, and its value is determined by the material of both slope parts, the processing of the slope, the surface roughness, etc. It also changes depending on whether or not lubrication is performed.
In general, when both slopes are metal surfaces, it is considered that μ = 0.4 when there is no lubrication and μ = 0.1 to 0.2 when there is lubrication. In the case of no lubrication, tan α <1 / 2.5, and in the case of lubrication, tan α <1/10 to 1/5. However, when the metal surface is finished very smooth, the friction coefficient may be considerably reduced. Therefore, it is preferable to appropriately set the slope angle α of the slope according to the case.

In addition, the part which touches the hole edge part of the stop hole 3 among the 1st slope part 210 and the 2nd slope part 220 should be processed into a curved surface shape so that it may match the shape of the hole edge part of the stop hole 3. preferable. By processing in this way, the first slope part 210 and the second slope part 220 are in close contact with the hole end portion of the stop hole 3, and the wedge means 4 is prevented from being displaced or dropped from the stop hole 3. it can.
Further, for example, the wedge means 4 may be displaced or dropped from the stop hole 3 such that the fitting portion 212 of the first slope component 210 is shaped so as to sandwich the hole ends of the stop hole 3 from both sides of the base plate 1. It is preferable to provide a drop-off preventing means for preventing. As a result, a load in the direction of opening the fatigue crack 2 acts on the base metal plate 1, the stop hole 3 spreads in the load direction (vertical direction in FIG. 8), the wedge load W becomes zero, and the wedge means 4 and the stop hole Even if the contact with 3 is loosened, it is possible to prevent the wedge means 4 from being displaced or dropped.
Further, as described in the first embodiment, before the wedge means 4 is fitted into the stop hole 3, the base material plate 1 or the like is formed by using a wire, chain, magnet, or the like having sufficient strength for the components of the wedge means 4. It is effective to prevent the component parts from falling.

  As described above, the fatigue crack repairing method and the repair member according to the fifth embodiment are capable of grasping the degree of load acting on the base material plate 1, and the degree of the load is the wedge load W applied in the present embodiment. This is particularly effective when it is predicted that the stress fluctuation width at the hole end of the stop hole 3 can be sufficiently suppressed.

  FIG. 9 is a schematic view showing a fatigue crack repair method and a repair member according to the sixth embodiment of the present invention. FIG. 9A shows a state in which an excessive load is applied to the base material plate, and FIG. ) Shows a state in which the wedge means is extended following the deformation of the stop hole, and FIG. 9C shows a state in which the excessive load is unloaded. In addition, the same code | symbol is attached | subjected to the same functional member as embodiment mentioned above, and description is abbreviate | omitted.

The repair member in the present embodiment is a wedge means 4 having a screw mechanism 200 and an automatic adjustment means 5.
The automatic adjustment means 5 includes a torque load member 241 that applies torque to the bolt 230 and a loading mechanism 242 that applies a load to the torque load member 241.
In the present embodiment, the torque load member 241 is an arm such as a hexagon wrench (wrench), and the loading mechanism 242 is a weight suspended from a high-strength rope. By configuring the torque load member 241 with an arm, torque can be applied to the bolt 230 by utilizing the rotation of the arm and the lever principle. Further, by configuring the loading mechanism 242 with a weight, it is possible to apply a load to the torque load member 241 using gravity. An engagement portion 241A that engages with the bolt 230 is provided at one end of the torque load member 241.

  In the fatigue crack repair method according to the present embodiment, a stop hole 3 is provided at the tip of the fatigue crack 2 generated in the base metal plate 1 in the same manner as the fatigue crack repair method according to the fifth embodiment (step 1). The wedge means 4 is fitted into the hole 3 (step 2), rotated by applying a torque N1 in the tightening direction to the bolt 230, and the second sloped part 220 is pushed by the tip of the bolt 230, so that the hole end of the stop hole 3 is obtained. A wedge load is applied to the part (step 3).

After step 3, the engagement portion 241A of the torque load member 241 is engaged with the bolt 230. Thereby, the bolt 230 and the torque load member 241 are connected. In addition, a loading mechanism 242 is connected to the other end of the torque load member 241. As a result, the load F is applied to the torque load member 241, and the torque N <b> 2 in the direction in which the second slope component 220 rises on the first slope component 210 is applied to the bolt 230.
Here, the torque N2 is much smaller than the torque N1 applied in step 3 (see FIG. 8), and the bolt 230 is not rotated by the torque N2 in a state where the wedge load W is not zero. .

An excessive load in the direction in which the fatigue crack 2 opens acts on the base metal plate 1 and the stop hole 3 extends greatly in the load direction, and the wedge load W applied to the hole end of the stop hole 3 in step 3 is increased. In the case where a slight gap is generated between the first slope part 210 and the second slope part 220 and the stop hole 3 (FIG. 9A), the bolt is immediately applied by the pre-loaded torque N2. 230 rotates, and the second slope part 220 rises on the first slope part 210 until the first slope part 210 and the second slope part 220 come into contact with the hole ends of the stop hole 3 (FIG. 9B). ).
When the excessive load is unloaded, the shape of the stop hole 3 extended by the excessive load tends to return to the original shape, whereas the bolt 230 does not rotate and the second slope part 220 is not rotated. Remains on the first slope part 210 as shown in FIG. 9B. Accordingly, a wedge load W ′ is generated at the hole end portion of the stop hole 3 at the time of unloading, but the second slope component 220 is raised above the first slope component 210 than at the time of initial fitting (state of FIG. 8). Therefore, the value of the wedge load W ′ is larger than the wedge load W before the excessive load is applied (FIG. 9C).
In this way, according to the present embodiment, a gap is generated between the first slope part 210 and the second slope part 220 and the hole end of the stop hole 3 after the wedge means 4 is fitted in step 3. Even if an excessive load acts on the base material plate 1, the second slope part 220 rises on the first slope part 210 due to the action of the torque load member 241 and the loading mechanism 242, and the wedge means 4 and the stop hole 3 When the contact is maintained and an excessive load of the same level is applied again after the excessive load is removed, an appropriate wedge load W ′ that does not cause loosening is automatically applied.
Accordingly, when an excessive load acts on the base plate 1 and the opening displacement of the hole portion of the stop hole 3 increases, the wedge means 4 is automatically adjusted to follow the opening displacement, and the wedge means 4 Since it can prevent loosening, there is no need to estimate the maximum load during operation and hold it under load, and after the overload unloading, an appropriate wedge load that is automatically adjusted according to the actual applied load To prevent cracks from recurring at the hole ends.
Note that the torque load member 241 preferably applies a substantially constant torque to the bolt 230. By making the torque substantially constant, it becomes easy to manage the wedge load applied to the hole end portion of the stop hole 3.

Here, the pushing stroke characteristic of the loading mechanism 242 is the characteristic that the bolt 230 always follows and continues to apply a load F of a certain level or more, that is, the bolt 230 is loaded with a torque N2 of a certain level or more. The upper limit is set for the amount of rotation of the bolt 230 and hence the amount of rise of the second sloped part 220, and when the load rises for a certain length, the loading mechanism 242 applies a further load. Whether or not the characteristic is such that the gap between the wedge means 4 and the stop hole 3 is allowed to some extent at the time of an overload action that exceeds a predetermined upper limit. The relationship between the length of fatigue crack 2, the maximum wedge load generated when unloading the external load, the strength of wedge means 4 and stop hole 3, and the object of repair Characteristics of the structure itself (thickness, redundancy, suppositories, etc. column strength) while taking into consideration, it is preferable to select as appropriate.
In addition, when an upper limit is set for the amount of rising of the second slope component 220, that is, a certain amount of gap (loosening) is allowed, and excessive gap spread over time, displacement and disengagement due to excessive gap spread, etc. In the case of the characteristic to prevent, the wedge means 4 or the base material plate which can be generated when the torque N2 of a certain level or more is continuously applied and the gap is completely prevented from being expanded to completely follow the opening displacement. 1 buckling, plastic deformation and the like can be prevented.

  As described above, the fatigue crack repairing method and repair member according to the sixth embodiment suppresses the hole end portion stress fluctuation width of the stop hole 3 while the repair member has a simple configuration, and the crack recurrence from the hole end portion. And the function of automatically adjusting the rusting means 4 following the opening displacement of the hole due to an excessive load, the degree of load acting on the base plate 1 is unknown or This is particularly effective when an excessive load is expected and the wedge load W applied in step 3 is not expected to sufficiently suppress the stress fluctuation width at the hole end.

  FIG. 10 is a schematic diagram showing a fatigue crack repair method and a repair member according to a seventh embodiment of the present invention. FIG. 10 (a) is a front view and FIG. 10 (b) is a right side view. In addition, the same code | symbol is attached | subjected to the same functional member as embodiment mentioned above, and description is abbreviate | omitted. Further, in order to make the structure easy to understand, a part of the structure is shown in FIG.

  In the present embodiment, a thermal expansion type wedge member 300 is used as the wedge means 4 that is a repair member. The thermal expansion type wedge member 300 is manufactured such that the dimension after thermal expansion is larger than the hole size of the stop hole 3.

  In the fatigue crack repair method according to the present embodiment, the stop hole 3 is provided at the tip of the fatigue crack 2 generated in the base metal plate 1 in the same manner as the fatigue crack repair method according to the first embodiment (step 1). The wedge means 4 having a variable wedge load is fitted into the hole 3 (step 2), and the wedge load is applied to the hole end of the stop hole 3 (step 3).

  In step 2, the thermal expansion type wedge member 300 that has been cooled and contracted by liquid nitrogen or the like is fitted into the stop hole 3. At this time, as shown in FIG. 10, it is preferable that the thermal expansion type wedge member 300 is disposed in the stop hole 3 so as to stand substantially perpendicular to the fatigue crack 2.

After step 2, when the fitted thermal expansion wedge member 300 is naturally or forcibly returned to room temperature and thermally expanded, the hole end of the stop hole 3 is pushed by the thermal expansion wedge member 300, and the stop hole 3 A wedge load W is applied to the end of the hole (step 3).
Thereby, the stress fluctuation width of the hole edge part of the stop hole 3 can be suppressed, and the crack recurrence from a hole edge part can be prevented.
When an excessive load is applied to the base material plate 1 and the opening displacement of the hole portion of the stop hole 3 is increased, the wedge load is adjusted by exchanging with a thermal expansion type wedge member 300 that expands more greatly (step) 4).

  As described above, the fatigue crack repair method and the repair member according to the seventh embodiment can grasp the degree of the load acting on the base material plate 1 and the degree of the load is the wedge load W applied in the present embodiment. This is particularly effective when it is predicted that the stress fluctuation width at the hole end of the stop hole 3 can be sufficiently suppressed.

  FIG. 11 is a schematic diagram showing a fatigue crack repair method and a repair member according to an eighth embodiment of the present invention. FIG. 11A is a rear view, and FIG. 11B is a right side view. In addition, the same code | symbol is attached | subjected to the same functional member as embodiment mentioned above, and description is abbreviate | omitted. Further, in order to facilitate understanding of the structure, a part of the structure is shown in FIG.

In the present embodiment, the wedge means 4 that is a repair member has a screw mechanism 400. The screw mechanism 400 includes a first divided female screw component 410 having a tapered female screw at one end, a second divided female screw component 420 having a tapered female screw at one end, and a tapered taper bolt 430.
The first divided female screw component 410 and the second divided female screw component 420 are arranged in the stop hole 3 so that one end sides where the tapered female screws are formed face each other. The tapered female thread portion 440 is configured such that the tapered bolt 430 is sandwiched between the two tapered female threads facing each other.
In this embodiment, a hexagon socket taper bolt is used as the taper bolt 430, but the type of taper bolt that can be used is arbitrary, and is not limited to the hexagon socket taper bolt.

  In the fatigue crack repair method according to the present embodiment, the stop hole 3 is provided at the tip of the fatigue crack 2 generated in the base metal plate 1 in the same manner as the fatigue crack repair method according to the first embodiment (step 1). The wedge means 4 having a variable wedge load is fitted into the hole 3 (step 2), and the wedge load is applied to the hole end of the stop hole 3 (step 3).

  In Step 2, the tapered female screw part 440 is configured by fitting the first divided female screw part 410 and the second divided female screw part 420 into the stop hole 3 with one end side where the tapered female screw is formed facing each other, The shaft portion of the taper bolt 430 is fitted to the tapered female screw portion 440. At this time, as shown in FIG. 11, it is preferable that the wedge means 4 is disposed in the stop hole 3 so as to stand substantially perpendicular to the fatigue crack 2.

After step 2, when the taper bolt 430 is rotated by applying torque N1 in a direction (tightening direction) to penetrate the tapered female screw portion 440, the first divided female screw component 410 and the second divided female screw component 420 are pressed against the tapered bolt 430. However, the other end of the first divided female screw component 410 and the other end of the second divided female screw component 420 are in contact with the hole end portion of the stop hole 3, so that the reaction force is exerted. And a wedge load W is applied to the hole end of the stop hole 3 (step 3).
Thereby, the stress fluctuation width of the hole edge part of the stop hole 3 can be suppressed, and the crack recurrence from a hole edge part can be prevented.
When an excessive load acts on the base material plate 1 and the opening displacement of the hole portion of the stop hole 3 increases, the wedge load is adjusted by tightening the taper bolt 430 and extending the wedge means 4 ( Step 4).

A portion of the other end of the first divided female screw part 410 and the other end of the second divided female screw part 420 that is in contact with the hole end of the stop hole 3 is curved so as to match the shape of the hole end of the stop hole 3. Preferably, it is processed into a shape. By processing in this way, the first divided female screw component 410 and the second divided female screw component 420 are brought into close contact with the hole end portion of the stop hole 3, and the wedge means 4 is displaced or dropped from the stop hole 3. Can be prevented.
Further, for example, the wedge means 4 has a shape in which the other end of the first divided female screw part 410 and the other end of the second divided female screw part 420 are sandwiched between the hole ends of the stop hole 3 from both sides of the base plate 1. In addition, it is preferable to provide a drop-off preventing means for preventing displacement and drop-off from the stop hole 3. As a result, a load in the direction of opening the fatigue crack 2 acts on the base material plate 1, the stop hole 3 spreads in the load direction (vertical direction in FIG. 11), and the wedge load W becomes zero. Even if the contact with 3 is loosened, it is possible to prevent the wedge means 4 from being displaced or dropped.
In addition, as described in the first embodiment, before the wedge means 4 is fitted into the stop hole 3, the base plate 1 or the components of the wedge means 4 can be formed using wires, chains, magnets or the like having sufficient strength. Locking to the largest component is effective as a measure to prevent the component from falling.

  As described above, the fatigue crack repairing method and the repair member according to the eighth embodiment can grasp the degree of load acting on the base material plate 1 and the degree of the load is the wedge load W applied in the present embodiment. This is particularly effective when it is predicted that the stress fluctuation width at the hole end of the stop hole 3 can be sufficiently suppressed.

  FIG. 12 is a schematic diagram showing a fatigue crack repair method and a repair member according to the ninth embodiment of the present invention. FIG. 12 (a) shows a state in which an excessive load is applied to the base material plate, and FIG. ) Shows a state in which the wedge means is extended following the deformation of the stop hole, and FIG. 12 (c) shows a state in which the excessive load is unloaded. In addition, the same code | symbol is attached | subjected to the same functional member as embodiment mentioned above, and description is abbreviate | omitted.

The repair members in this embodiment are a wedge means 4 and an automatic adjustment means 5 having a screw mechanism 400.
The automatic adjustment means 5 includes a torque load member 451 that applies torque to the taper bolt 430 and a loading mechanism 452 that applies a load to the torque load member 451.
In the present embodiment, the torque load member 451 is an arm such as a hexagon wrench (wrench), and the loading mechanism 452 is a weight suspended from a high-strength rope. By configuring the torque load member 451 with an arm, torque can be applied to the taper bolt 430 by utilizing the rotation of the arm and the lever principle. Further, by configuring the loading mechanism 452 with a weight, it is possible to apply a load to the torque load member 451 using gravity. An engagement portion 451A that engages with the taper bolt 430 is provided at one end of the torque load member 451.

  In the fatigue crack repair method according to the present embodiment, the stop hole 3 is provided at the tip of the fatigue crack 2 generated in the base metal plate 1 in the same manner as the fatigue crack repair method according to the eighth embodiment (step 1). By fitting the wedge means 4 into the hole 3 (step 2) and rotating the taper bolt 430 by applying a torque N1 in the tightening direction, the gap between the first divided female screw part 410 and the second divided female screw part 420 is increased. Then, a wedge load is applied to the hole end portion of the stop hole 3 (step 3).

After step 3, the engagement portion 451A of the torque load member 451 is engaged with the taper bolt 430. Thereby, the taper bolt 430 and the torque load member 451 are connected. Further, a loading mechanism 452 is connected to the other end of the torque load member 451. As a result, the load F is applied to the torque load member 451, and the torque N <b> 2 is applied to the taper bolt 430 in a direction that widens the distance between the first divided female screw part 410 and the second divided female screw part 420.
Here, the torque N2 is much smaller than the torque N1 applied in step 3 (see FIG. 11), and the taper bolt 430 does not rotate by the torque N2 in a state where the wedge load W is not zero. .

An excessive load in the direction in which the fatigue crack 2 opens acts on the base metal plate 1 and the stop hole 3 extends greatly in the load direction, and the wedge load W applied to the hole end of the stop hole 3 in step 3 is increased. In the case where a slight gap is generated between the first divided female screw part 410 and the second divided female screw part 420 and the hole end portion of the stop hole 3 (FIG. 12A), it is preloaded. The taper bolt 430 is immediately rotated by the torque N2, and the first divided female screw part 410 and the second divided female screw part 410 and the second divided female screw part 420 and the other end of the second divided female screw part 420 come into contact with the hole end of the stop hole 3 and The space | interval with the 2 division | segmentation internal thread component 420 is pushed wide (FIG.12 (b)).
When the excessive load is unloaded, the shape of the stop hole 3 extended by the excessive load tends to return to the original shape, whereas the taper bolt 430 does not rotate and the first divided female screw part The distance between 410 and the second divided female screw part 420 remains as shown in FIG. Accordingly, a wedge load W ′ is generated at the hole end portion of the stop hole 3 at the time of unloading, but the interval between the first divided female screw part 410 and the second divided female screw part 420 is wider than that at the time of initial fitting (state of FIG. 11). Therefore, the value of the wedge load W ′ is larger than the wedge load W before the excessive load is applied (FIG. 12C).
In this way, according to the present embodiment, after the wedge means 4 is fitted in step 3, a gap is generated between the first divided female screw part 410 and the second divided female screw part 420 and the hole end of the stop hole 3. Even if such an excessive load acts on the base material plate 1, the wedge load 4 is generated by the action of the torque load member 451 and the loading mechanism 452 and the distance between the first divided female screw part 410 and the second divided female screw part 420 is expanded. When the contact with the hole end of the stop hole 3 is maintained and an excessive load of the same level is applied again after unloading the excessive load, an appropriate wedge load W ′ that does not cause loosening is automatically applied. Is done.
Accordingly, when an excessive load acts on the base plate 1 and the opening displacement of the hole portion of the stop hole 3 increases, the wedge means 4 is automatically adjusted to follow the opening displacement, and the wedge means 4 Since it can prevent loosening, there is no need to estimate the maximum load during operation and hold it under load, and after the overload unloading, an appropriate wedge load that is automatically adjusted according to the actual applied load To prevent cracks from recurring at the hole ends.
Note that the torque load member 451 preferably applies a substantially constant torque to the taper bolt 430. By making the torque substantially constant, it becomes easy to manage the wedge load applied to the hole end portion of the stop hole 3.

Here, the pushing stroke characteristic of the loading mechanism 452 is a characteristic in which the taper bolt 430 always follows and continues to apply a load F of a certain level or more, that is, the taper bolt 430 is loaded with a torque N2 of a certain level or more. The upper limit is set for the amount of rotation of the taper bolt 430 and the distance between the first divided female screw part 410 and the second divided female screw part 420 to be expanded, and the taper bolt 430 is expanded by a certain length. In such a case, the load mechanism 452 does not load any more load, that is, the gap between the wedge means 4 and the hole end of the stop hole 3 is set to some extent when an excessive load is applied that exceeds a predetermined upper limit. Whether it is acceptable characteristics is the maximum external load applied to the part, the length of the fatigue crack 2, and the maximum that occurs when the external load is unloaded. Relationship of the intensity of rust load and wedge means 4 and the stop hole 3, properties of the structure itself as a target of repair (thickness, redundancy, suppositories, etc. column strength) while taking into consideration, it is preferable to select as appropriate.
In addition, when an upper limit is set for the amount by which the distance between the first divided female screw part 410 and the second divided female screw part 420 is pushed and widened, that is, a certain amount of gap (loosening) is allowed, and an excessive gap spread over time. In the case of a characteristic that prevents displacement or disconnection due to an excessive gap expansion, the characteristic is to continue to apply a torque N2 of a certain level or more, to prevent any gap expansion and to follow the opening displacement completely. It is possible to prevent the wedge means 4 or the base material plate 1 from being buckled or plastically deformed.

  As described above, the fatigue crack repair method and the repair member according to the ninth embodiment suppress the hole end portion stress fluctuation width of the stop hole 3 while the repair member has a simple configuration, and the crack recurrence from the hole end portion. And the function of automatically adjusting the rusting means 4 following the opening displacement of the hole due to an excessive load, the degree of load acting on the base plate 1 is unknown or This is particularly effective when an excessive load is expected and the wedge load W applied in step 3 is not expected to sufficiently suppress the stress fluctuation width at the hole end.

FIG. 13 is a schematic diagram showing another example of the automatic adjustment means, FIG. 13 (a) is a front view, and FIG. 13 (b) is a right side view. For easy understanding of the structure, a part of the structure is shown in FIG.
In this example, in the repair member of the sixth embodiment (see FIG. 9), the torque load member that generates the torque N1 in the bolt 230 is replaced with a torque load member 241 configured using an arm, and a pulley is used. The torque load member 541 is configured as described above. That is, the automatic adjustment means 5 in this example includes a torque load member 541 that applies torque to the bolt 230 and a loading mechanism 542 that applies a load to the torque load member 541. An engagement portion 541A that engages with the bolt 230 is provided at one end of the torque load member 541.
One end of a wire is fixed to the torque load member 541, and a weight as a loading mechanism 542 is suspended from the other end of the wire. This example is different from the sixth embodiment in that the torque load member 541 is configured by a pulley, but also in this example, after the wedge means 4 is fitted in Step 3, the first slope part 210 and the second Even if an excessive load that causes a gap between the slope part 220 and the hole end portion of the stop hole 3 is applied to the base material plate 1, the second slope part 220 is moved by the action of the torque load member 541 and the loading mechanism 542. The screw mechanism 200 and the end of the hole 3 of the stop hole 3 are kept in contact with the first slope component 210 and are loosened even when the same excessive load is applied again after the excessive load is removed. The principle that the appropriate wedge load W ′ is applied automatically is the same as in the sixth embodiment.
In addition, it is preferable to wind a wire around the pulley several times. By winding the wire several times, the torque acting on the bolt 230 is not lost even if the rotation angle of the bolt 230 increases. On the other hand, if it is known in advance that the rotation angle of the bolt 230 does not exceed 360 degrees, a gear and a chain may be used instead of the pulley and the wire.

  When the torque load member is composed of an arm, the torque acting on the bolt or the like may change depending on the angle of the arm, but when the torque load member is composed of a pulley (pulley) as in this example Can always apply a constant torque to a bolt or the like. If the torque applied to the bolt or the like is always constant, the wedge load can be easily managed.

A scale 543 is provided on the outer periphery of the torque load member 541 (pulley). By reading the scale 543 by an appropriate method, the rotation angle of the torque load member 541, that is, the rotation angle of the bolt 230 can be easily grasped. Now, the pitch of the bolt 230 is p (mm), the rotation angle of the bolt 230 is Δθ (deg), the inclination angles of the slopes of the first slope part 210 and the second slope part 220 are α (deg), and the upper and lower sides of the wedge means 4 When the increment in the direction length (= the opening increment of the stop hole 3) is ΔL (mm), the relationship of the following expression (2) is established.

[Formula 2]
ΔL = p × (Δθ / 360) × tan α (2)

Therefore, by reading the rotation angle Δθ of the bolt 230 from the scale 543 of the torque load member 541, the opening increment ΔL of the stop hole 3 can be easily estimated, and the load acting on the base material plate 1 can be estimated, Information useful for determining the presence or absence of recurrent cracks from the stop hole 3 can be acquired.
In addition, although the case where the torque load member comprised with the pulley was applied to 6th embodiment was demonstrated in this example, it can be similarly applied to 4th embodiment and 9th embodiment. That is, the torque load member of the fourth embodiment or the ninth embodiment can be configured by a pulley instead of an arm.

14A and 14B are schematic views showing still another example of the automatic adjustment means. FIG. 14A is a front view and FIG. 14B is a right side view. For easy understanding of the structure, a part of the structure is shown in FIG.
In this example, in the repair member of the sixth embodiment (see FIG. 9), the automatic adjustment means 5 is configured using a spiral spring 641 instead of the arm and the weight.
One end of the spiral spring 641 is provided with an engaging portion 641A that engages with the bolt 230. One end of the spiral spring 641 is fixed to the head of the bolt 230 by the engaging portion 641A, and the other end is fixed to the parallel portion 211 of the first slope component 210 via the adjustment tool 642. The adjustment tool 642 is for adjusting the degree of winding of the spiral spring 641. By adjusting the tightening degree of the spiral spring 641 by the adjusting tool 642, an appropriate torque N1 can be applied to the head of the bolt 230.
This example is different from the sixth embodiment in that the automatic adjustment means 5 is configured by using the spiral spring 641, but the first slope part 210 and the second slope after the wedge means 4 is fitted in Step 3. Even if an excessive load that causes a gap between the part 220 and the hole end of the stop hole 3 is applied to the base material plate 1, the second slope part 220 is moved to the first slope part 210 by the action of the automatic adjustment means 5. Appropriate wedge load W ′ that does not cause loosening even when the excessive load of the same level is applied again after the excessive load is removed after the contact between the wedge means 4 and the stop hole 3 is maintained. Is the same as in the sixth embodiment.

According to this example, it is not necessary to use a weight for the automatic adjustment means 5, and it is sufficient to secure a space where the spiral spring 641 relaxes and spreads. Therefore, a space smaller than the installation space of the automatic adjustment means 5 using the weight. Even can be installed. In addition, measures to prevent the weight from falling are not required.
Further, by appropriately selecting the length of the spiral spring 641, it is possible to set the torque acting on the bolt 230 not to be lost even if the rotation angle of the bolt 230 is increased.
In addition, although the example which applied the automatic adjustment means using a spiral spring to 6th embodiment was demonstrated in this example, it can be similarly applied to 4th embodiment and 9th embodiment. That is, the automatic adjustment means of the fourth embodiment or the ninth embodiment can be configured using a spiral spring instead of the arm and the weight.

FIGS. 15A and 15B are schematic views showing still another example of the automatic adjusting means. FIG. 15A is a front view and FIG. 15B is a right side view. For easy understanding of the structure, a part of the structure is shown in FIG.
In this example, in the repair member of the sixth embodiment (see FIG. 9), the automatic adjustment means 5 is configured using a coil spring 741 instead of the arm and the weight.
The coil spring 741 is located between the bolt 230 and the second slope part 220. One end of the coil spring 741 is in contact with the tip of the bolt 230, and the other end is in contact with the side surface of the second slope component 220.
After the wedge means 4 is fitted into the stop hole 3, it is rotated by applying a torque in the direction of tightening the bolt 230, and by adjusting the contraction of the coil spring 741, an appropriate pressing force is applied to the side surface of the second slope component 220. P1 can be applied, whereby a wedge load is applied to the hole end of the stop hole 3.
This example is different from the sixth embodiment in that the automatic adjustment means 5 is configured by using the coil spring 741, but after the wedge means 4 is fitted in Step 3, the first slope part 210 and the second slope surface are provided. Even if an excessive load that causes a gap between the part 220 and the hole end of the stop hole 3 is applied to the base material plate 1, the second slope part 220 is moved to the first slope part 210 by the action of the automatic adjustment means 5. When the contact between the screw mechanism 200 and the stop hole 3 is maintained, and an excessive load of the same level is applied again after the unloading of the excessive load, an appropriate wedge load W ′ that does not cause loosening is provided. Is the same as in the sixth embodiment.
In addition, it can replace with the coil spring 741 and can also use the member which can accumulate | store elastic force at the time of compression, such as a disk spring or rubber | gum. In addition, two powerful magnets having the same polarity (N pole and N pole, S pole and S pole) repelling each other are arranged in close proximity to each other, and the repulsive force due to the magnetic force is substituted for the elastic force of the coil spring 741. Can also be used.

According to this example, since the automatic adjustment means 5 (coil spring 741) can be accommodated inside the outer dimension of the wedge means 4, the wedge means 4 and the automatic adjustment means even in a relatively narrow structure portion. 5 can be installed.
Further, by appropriately selecting the length of the coil spring 741, the pressing force P1 can be set so as not to be lost even when the movement amount of the second slope component 220 is increased.

FIG. 16 is a schematic diagram showing an example of the drop-off preventing means, FIG. 16 (a) is a front view, and FIG. 16 (b) is a right side view. In order to make the structure easy to understand, a part of the structure is shown in FIG.
In this example, in the repair member (see FIG. 8) of the fifth embodiment, the wedge means 4 is provided with drop-off prevention means.
The drop-off preventing means includes a pair of hooks 250 protruding from the bottom surface of the first slope component 210 and a connecting member 260 that connects the first slope component 210 and the second slope component 220.
The hook-shaped portion 250 has one hook-shaped portion 250A and the other hook-shaped portion 250B. A space slightly larger than the thickness of the base material plate 1 is provided between the one hook-shaped portion 250A and the other hook-shaped portion 250B. One hook-shaped portion 250A is disposed on the back side of the base material plate 1, the other hook-shaped portion 250B is disposed on the front side of the base material plate 1, and between the one hook-shaped portion 250A and the other hook-shaped portion 250B. By positioning the base material plate 1 in this space, the base material plate 1 (hole end portion of the stop hole 3) can be sandwiched from both sides by one hook-like portion 250A and the other hook-like portion 250B. In addition, a bolt female thread into which the fixing bolt 250C is screwed is formed on the other hook-shaped portion 250B. This bolt female thread penetrates the other flange-shaped part 250B, and the shaft part of the fixing bolt 250C is longer than the bolt female thread. As shown in FIG. 16 (b), the first slope component 210 is firmly fixed to the base material plate 1 by screwing the fixing bolt 250 </ b> C into the bolt female screw and bringing the tip into contact with the base material plate 1. be able to.
The connecting material 260 is, for example, a wire or a chain. After passing one connecting material 260 through the through holes provided in each of the first slope component 210 and the second slope component 220, one end side and the other end side of the connecting material 260 are connected to make the connecting material 260 annular. It is said. In addition, the 1st slope component 210 and the 2nd slope component 220 can also be connected by fixing one end of the connection material 260 to the 1st slope component 210, and fixing the other end to the 2nd slope component 220.
By connecting the second slope component 220 to the first slope component 210 fixed to the base material 1 by the hook-shaped portion 250 with the connecting material 260, the second slope component 220 can be prevented from falling off the stop hole 3.

FIG. 17 is a schematic diagram showing another example of the drop-off preventing means, FIG. 17 (a) is a rear view, and FIG. 17 (b) is a right side view. For easy understanding of the structure, a part of the structure is shown in FIG.
In this example, in the repair member (see FIG. 11) according to the eighth embodiment, the wedge means 4 is provided with a drop prevention means.
The drop-off preventing means includes a pair of first hooks 450 protruding from both sides of the other end of the first divided female screw part 410 and a pair of second hooks protruding from both sides of the other end of the second divided female screw part 420. And 460.
The first hook-like portion 450 has one protrusion 450A and the other protrusion 450B. The second hook-like portion 460 has one protrusion 460A and the other protrusion 460B. Spaces slightly larger than the thickness of the base material plate 1 are provided between the one protrusion 450A, 460A and the other protrusion 450B, 460B. One projecting portion 450A, 460A is disposed on the back side of the base material plate 1, the other projecting portion 450B, 460B is disposed on the front side of the base material plate 1, and one projecting portion 450A, 460A and the other projecting portion 450B, By positioning the base material plate 1 in the space between 460B, the base material plate 1 (hole end portion of the stop hole 3) is sandwiched from both sides by the first hook-like portion 450 and the second hook-like portion 460. Can be swallowed.
The drop-off preventing means may be manufactured integrally with the first divided female screw part 410 or the second divided female screw part 420, or may be manufactured using a resin or the like and the other end of the first divided female screw part 410 and You may affix on the other end of the 2nd division | segmentation internal thread component 420. FIG.

  In addition, although the case where the drop prevention means is applied to the fifth embodiment (FIG. 8) and the eighth embodiment (FIG. 11) as an example of the drop prevention means has been described with reference to FIGS. The prevention means can also be applied to the first to fourth, sixth, seventh and ninth embodiments.

FIG. 18 is a schematic diagram showing a fatigue crack repair method and a repair member according to the tenth embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the same functional member as embodiment mentioned above, and description is abbreviate | omitted.
In the first to ninth embodiments described above, it has been described that the wedge means 4 is applied to the stop hole 3 provided at the front end portion of the fatigue crack 2, but the wedge means 4 includes the base portion and the front end portion of the fatigue crack 2. You may apply to the wedge hole 7 which is a drill hole provided on crack paths other than. Moreover, the stop hole 3 and the wedge hole 7 may be provided side by side and applied to both.
Furthermore, the number of wedge holes 7 is arbitrary, and when the fatigue crack 2 is long, a plurality of wedge holes 7 may be provided on the crack path. In that case, if the automatic adjustment means 5 is provided in the repair member, the wedge means 4 follows the crack opening by the automatic adjustment means 5 even if the opening amount of the fatigue crack 2 is large or small depending on the position of the wedge hole 7. Thus, the optimum initial wedge load at the position of each wedge hole 7 is automatically applied.
FIG. 18 shows a fatigue crack 2 generated in the base material plate 1, provided with a stop hole 3 at the tip of the fatigue crack 2 and one wedge hole 7 on the crack path, each having a screw mechanism 200. The example which repairs by applying the wedge means 4 is shown. Thereby, the stress fluctuation width of the structure can be suppressed, and crack recurrence can be prevented.
Even when the wedge means 4 is applied to the wedge hole 7, it is effective to provide the wedge means 4 with a drop-off preventing means as a measure for preventing the component parts from dropping.

  In the fatigue crack repair method according to the first to tenth embodiments described above, steps 1 to 3 can be performed from one side of the structure. Therefore, repair work can be performed even when work can be performed only from either the front side or the back side of the structure in which the fatigue crack has occurred.

FIG. 19 is a diagram showing the effect of suppressing the fluctuation range of the hole end stress according to the present invention. The vertical axis represents the hole end stress σ, and the horizontal axis represents the tensile load P.
The stop hole 3 provided at the tip of the fatigue crack 2 schematically shows how the variation range Δσ of the hole end portion stress σ of the stop hole changes for each of the following cases (1) to (3). Is.
(1) When not reinforced by the wedge means 4 (2) When reinforced by the repair method and repair member according to any of the first, third, fifth, seventh and eighth embodiments (3) Second, fourth, sixth, When reinforced with a repair method and repair member according to any of the nine embodiments

(1) When the wedge means 4 is not reinforced When the tensile load P (horizontal axis in FIG. 19) acting in the direction of opening the fatigue crack 2 generated in the base metal plate 1 is zero, the hole end stress of the stop hole 3 σ (vertical axis in FIG. 19) is also zero, and as the tensile load P increases, σ increases linearly. In FIG. 19, the σ-P relationship graph is a straight line connecting the origin and the maximum load point B (however, There shall be no plastic deformation at the hole end).
In this case, the fluctuation range Δσ of the hole end portion stress σ = maximum stress σ _max −minimum stress zero = σ _max (“no reinforcement Δσ” in FIG. 19).

(2) When reinforced with the repair method and the repair member according to any of the first, third, fifth, seventh and eighth embodiments, even when the tensile load P is zero, the wedge member wedges at the hole end of the stop hole 3 the initial stress σ _w is generated by the load (point a). When the tensile load P increases in this state, the hole end stress σ increases linearly. However, as long as the contact between the wedge means 4 and the stop hole 3 is maintained, the apparent rigidity of the hole becomes wedge means 4. Therefore, the slope of the stress increase becomes gentler than in the case of (1) (point A → point S).
At the point S, if the tensile load P _s that the wedge means 4 first loosens acts, the wedge load by the wedge means 4 becomes zero in the region where the tensile load more than that acts, so the apparent rigidity of the hole is wedged. This is the same as the case of (1) without the means 4, and the slope of the graph (straight line) in the σ-P relationship is also equal (point S → point B).
If the maximum tensile load P _max is applied at the point B and is subsequently unloaded, the route of point B → point S → point A, which is the reverse of the above-described loading process, is followed. Accordingly, the variation range .DELTA..sigma hole end forces' = maximum stress sigma _{max -} next initial stress sigma _w, ( "reinforcing There .DELTA..sigma in Figure 19 in which the is suppressed by sigma _w min than .DELTA..sigma (1) '').

(3) In the case where the repair method and the repair member according to any of the second, fourth, sixth, and ninth embodiments are reinforced, the process of increasing the stress at the hole end in the path of point A → point S → point B Same as 2), but in the process from point S to point B, the end of the wedge means 4 follows the deformation of the stop hole 3 (elongation in the tensile load direction) and loosens between the hole end of the stop hole. Since the wedge means 4 automatically stretches so as not to move, the wedge means 4 acts as a wedge that prevents deformation of the stop hole 3 (shrinkage in the tensile load direction) as soon as the unloading process starts from the maximum load point B. During this period, a wedge load is generated, and its value increases as the unloading process proceeds. As a result, the apparent rigidity of the hole is increased by the amount of the wedge means 4 in the same manner as the area of points A to S, and the slope of the graph (straight line) of the σ-P relationship in the unloading process (point B → point C) is equal to the slope of the point S → point a, in the tensile load becomes zero unloading is completed point C, (2) initial stress that is automatically adjusted to a value greater than granted initial stress sigma _w in sigma _w 'Will be given. Therefore, the fluctuation range Δσ ″ of the hole end portion stress is the maximum stress σ _max −the automatically adjusted initial stress σ _w ′, which is further suppressed by (σ _w ′ −σ _w ) more than Δσ ′ of (2). (“Δσ ″ after automatic adjustment” in FIG. 14).
In general, the magnitude of the external load acting during the operation of the structure is probabilistically distributed, and it is not easy to deterministically correctly estimate the maximum (excessive) load value. Even if it acts, it is often very difficult to keep the fatigue crack 2 open, especially in large structures, whereas in the case of (3), it acts during operation. The wedge means 4 automatically extends according to the maximum (excessive) load P _max to be applied, and an appropriate initial stress σ _w ′ at the time of unloading is also automatically applied. Applicability and effectiveness are greatly improved.

Here, the effect of suppressing the fluctuation range of the hole end stress σ when the stop hole 3 provided at the crack tip is reinforced by the wedge means 4 has been described, but the wedge provided in the crack propagation path as in the tenth embodiment. Even when the hole 5 is reinforced by the wedge means 4, the same fluctuation width suppressing effect can be expected with respect to the stress σ at the crack tip or the end of the stop hole 3 provided at the crack tip.
In the first, third, fifth, seventh, and eighth embodiments, when an excessive load is applied to the base plate 1 and the opening displacement of the hole of the stop hole 3 increases, the opening displacement is manually followed. Even when the wedge means 4 is adjusted to prevent the wedge means 4 from loosening, the same effect as in (3) can be obtained.
The drawings corresponding to the first to tenth embodiments described above show the outline thereof, and the configuration necessary for actually carrying out the present invention can be adopted as appropriate.
Further, the wedge means 4 can be configured using a hydraulic mechanism, a spring mechanism, or the like, or a combination of these mechanisms, instead of the screw mechanism. In addition, the screw mechanism can include any mechanism that can apply a wedge load using a screw.

  A static loading test that verifies the effect of the repair method of the fatigue crack and the member for repair will be described as Example 1. In this example, the fatigue crack repair method and repair member according to the fifth embodiment described above were used.

FIG. 20 is a diagram showing a flat plate test piece used in the test.
The flat test piece 1A is a machined base material obtained by grinding a JIS SM400B steel plate having a thickness of 12 mm to a thickness of 10 mm, and has a notch 2A and a circular hole 3A at the center as shown in FIG. . The notch 2A simulates the fatigue crack 2, and the circular hole 3A simulates the stop hole 3 provided at the tip of the fatigue crack.

FIG. 21 is a view showing the wedge means used in the test.
The wedge means 4 having the screw mechanism 200 was manufactured using JIS SUS316 stainless steel. As shown in FIG. 21, the screw mechanism 200 includes a first slope part 210 in which a bolt female screw is formed, a second slope part 220 that slidably contacts on the first slope part 210, and a first slope part 210. It is comprised with the volt | bolt 230 screwed into the volt | bolt internal thread. The bolt 230 is a hexagon socket head cap screw with a pitch of 0.7 mm. The slope angle α of the slope was tan α = 1/7.

An electro-hydraulic servo type fatigue tester (manufactured by Shimadzu Corporation, dynamic capacity: 10 tonf) was used as the tester.
After attaching the flat plate test piece 1A to the hydraulic chuck of the testing machine, the wedge means 4 was attached to the circular hole 3A in the center. As for the tightening amount of the bolt 230, the bolt 230 is turned in the tightening direction using a hexagon wrench from the state where the bolt 230 is completely relaxed, and the tip of the spherical bolt hits the side surface of the second slope component 220. Starting from the state in which resistance was felt when turning the bolt 230 in contact with the bolt 230, the bolt was further rotated by an angle of 225 degrees in the tightening direction, and initial tightening was performed. Since the pitch of the bolts 230 is 0.7 mm, the amount of axial movement of the bolts 230 by initial tightening is 0.7 × 225/360 = 0.44 mm.

In the static loading test, a uniaxial strain gauge with a gauge length of 2 mm is attached to the hole end of the circular hole 3A opposite to the notch 2A of the flat plate test piece 1A to measure the circular hole end strain during the static loading test. did.
In the static loading test, the process of gradually increasing the tensile load P in the longitudinal direction of the flat specimen 1A from zero to the maximum tensile load P _max = 14.5 kN and then gradually decreasing to zero again is defined as one cycle, and the wedge means 4 is used. Loading was performed for 1 cycle when there was not, and 2 cycles when the wedge means 4 was used.

FIG. 22 is a diagram showing the relationship between the hole end strain and the tensile load.
In FIG. 22, the relationship between the circular hole end strain ε and the tensile load P is shown for each of the case where the wedge means 4 is not used and the case where it is used. The black plot points of “with wedge means” (when wedge means 4 are used) are scattered on the vertical axis because of the initial tightening of the bolt 230 performed with zero tensile load. This represents a process in which the end strain ε increases.
In FIG. 22, the white plot points are the results of “no wedge means” (when the wedge means 4 is not used). The hole end strain ε, which was zero at the tensile load P = 0, increases almost linearly as the tensile load P increases. In the unloading process after reaching the maximum tensile load P _max , the increasing process is almost reversed. It can be seen that it decreases after going through the process.
On the other hand, looking at the black-painted plot points with “wedge means”, as described above, the circular hole end strain ε significantly increases due to the initial tightening of the bolt 230, and the value of the circular hole end strain ε at the completion of the initial tightening. Was 700 μm. Thereafter, when the tensile load P rises, the circular hole end strain ε increases with a gentler gradient than the case of “without wedge means” while exhibiting a slight non-linearity on the upper side, and reaches the maximum tensile load P _max. In the subsequent unloading process, it decreases through a process that almost follows the ascending process, and at a tensile load P = 0, it reaches a value slightly exceeding the circular hole end strain ε at the time of completion of initial tightening (719 μ). is decreasing. Here, when the round hole end strain range which is the first dominant factor of fatigue damage at the hole end portion of the circular hole 3A is obtained,
-Circular hole end strain range when the wedge means 4 is not used Δε ₀ = 1450 μ
・ Strain range Δε _w = 849 μ in case of using the wedge means 4
Thus, it was found that the use of the wedge means 4 significantly reduces the circular hole end strain range to 58.6% when the wedge means 4 is not used.

  A static loading test that verifies the effect of the repairing method of fatigue cracks and the member for repairing will be described as Example 2. In this example, the fatigue crack repair method and repair member according to the sixth embodiment described above were used. However, the torque load member was configured using a pulley instead of an arm.

Since the flat plate test piece used for the test has the same specifications as the flat plate test piece 1A used in Example 1, refer to FIG.
Moreover, since the wedge means used for the test is the same specification as the wedge means 4 used in Example 1, please refer to FIG.

FIG. 23 is a view showing a half of the pulley constituting the torque load member used in the test, FIG. 23 (a) is a right side view, and FIG. 23 (b) is a front view.
The pulley (torque load member) 541 was formed by processing a disc of JIS A5052 aluminum alloy, and fitting the head of the bolt 230 of the wedge means 4 into the center hole and fixing it.

An electro-hydraulic servo type fatigue tester (manufactured by Shimadzu Corporation, dynamic capacity: 10 tonf) was used as the tester.
After attaching the flat plate test piece 1A to the hydraulic chuck of the testing machine, the wedge means 4 was attached to the circular hole 3A in the center. When a torque is applied to the bolt 230 penetrating into the center of the pulley 541, the pulley 541 is passed through an octopus thread simulating a wire fixed by tying a knot on the large drill hole 541C side to the small drill hole 541B formed in the pulley 541. After the octopus thread is wound around the outer circumference of the octopus, the octopus thread is stretched diagonally upward and hooked on a metal round bar installed horizontally at an appropriate height to change the direction of the octopus thread vertically downward. Tension was generated by hanging a weight as a loading mechanism 542 at the tip, and torque was generated on the bolt 230 by rotating the pulley 541. In addition, the rotation amount of the pulley 541 was measured by installing the CCD scope so that the vicinity of the outer periphery of the pulley 541 is in the field of view and appropriately reading the scale 543 of the pulley 541.
The initial tightening amount of the bolt 230 is that the bolt 230 fixed to the pulley 541 and the pulley 541 are turned in the tightening direction from the state where the bolt 230 is completely relaxed, and the spherical bolt tip is the second slope part. Starting from the state in which resistance is felt when the bolt 230 is turned against the side surface of 220, the weight 542 for 430g is suspended from the tip of the octopus thread, and the pulley 541 is angled in the tightening direction. Rotated by 54.2 degrees. Since the pitch of the bolts 230 is 0.7 mm, the amount of axial movement of the bolts 230 when the weight 542 is suspended is 0.7 × 54.2 / 360 = 0.11 mm.

In the static loading test, a uniaxial strain gauge with a gauge length of 2 mm is attached to the hole end of the circular hole 3A opposite to the notch 2A of the flat plate test piece 1A to measure the circular hole end strain during the static loading test. did.
In the static loading test, the process of gradually increasing the tensile load P in the longitudinal direction of the flat test piece 1A from zero to the maximum tensile load P _max = 14.5 kN and then gradually decreasing it to zero again is one cycle, and the wedge means 4 is used. 3 cycles of loading were performed.

FIG. 24 is a diagram showing the relationship between the pulley rotation angle and the tensile load.
FIG. 24 shows the relationship between the pulley rotation angle θ and the tensile load P when the wedge means 4 is used. As described above, the pulley 541 and the bolt 230 fixed to the pulley 541 are rotated in the tightening direction from the state in which the bolt 230 is completely relaxed, and the spherical bolt tip portion contacts the side surface of the second sloped part 220. Starting from the state where resistance was felt when the bolt 230 was turned in contact (θ = 0 °), a weight 542 corresponding to 430 g was suspended from the tip of the octopus thread, and the pulley 541 was tightened. Rotated by an angle of 54.2 degrees. Thereafter, when the tensile load P is gradually increased, the second inclined surface in which the circular hole 3A of the flat plate test piece 1A is extended in the longitudinal direction of the flat plate test piece 1A and continues to receive the pressure from the bolt tip on the side surface. The part 220 rises on the first slope part 210 in a form following the deformation of the circular hole 3A. At the same time, the bolt 230 rotates in the tightening direction by the amount of movement of the second slope part 220, and the rotation angle of the pulley 541 is increased. Will increase. Referring to FIG. 24, the relationship between the rotation angle of the pulley 541 and the tensile load P in the process of increasing the load in the first cycle is almost linear, and the wedge means 4 closely follows the deformation of the circular hole 3A as the load increases. It can be seen that it is stretched.
When the tensile load P reaches the maximum tensile load P _max and enters the subsequent unloading process, the wedge means 4 satisfies the relationship of the formula (1), so that the elongated circular hole 3A has the original shape. Even if a compressive load is applied to the upper and lower ends of the wedge means 4 for returning, the second slope part 220 starts to slide on the first slope part 210 due to the frictional force between the first slope part 210 and the second slope part 220. In addition, since the bolt 230 does not rotate in the loosening direction, the rotation angle of the pulley 541 becomes substantially constant. Referring to FIG. 24, after the tensile load P is returned to zero (after completion of the first cycle), the rotation angle of the pulley 541 is substantially constant even when the second cycle is loaded, and is slightly increased when the maximum tensile load P _{max is} loaded. After the increase, it is understood that the constant value is maintained until the unloading of the third cycle is completed.

FIG. 25 is a diagram showing the relationship between the circular hole end strain ε and the tensile load P for each of the case where the wedge means 4 is not used and the case where the wedge means 4 is used. In addition, the data (refer FIG. 22) acquired in Example 1 are used as it is as data when the wedge means 4 is not used.
In FIG. 25, the white plot points indicate the result of “without wedge means” (when the wedge means 4 is not used). The hole end strain ε, which was zero at the tensile load P = 0, increases almost linearly as the tensile load P increases. In the unloading process after reaching the maximum tensile load P _max , the increasing process is almost reversed. It can be seen that it decreases through a process of tracing.
On the other hand, the black plot points indicate the results of “with wedge means” (when the wedge means 4 is used). The plot point slightly increased on the vertical axis due to the suspension of the weight 542, and the value of the circular hole end strain ε at the completion of the suspension was 283μ. Thereafter, when the tensile load P increases, the circular hole end strain ε increases substantially linearly in parallel with the case of “no wedge means”, and the value of the circular hole end strain ε when the maximum tensile load P _{max is} reached is 1698 μm. It was. On the other hand, in the subsequent unloading process, since the rusting means 4 extends so as to follow the deformation (elongation) of the circular hole 3A when the load increases, the circular hole 3A remains in the original state even when the load is unloaded. The circular hole end strain ε decreases with a gentler slope than in the case of “without wedge means”, and the circular hole end strain ε = 991 μm when unloading of the first cycle is completed. It has become. Thereafter, in the second and third cycles, the plot point is located on the above-mentioned gentle slope in both the load increasing process and the unloading process, and the hole end strain at the completion of the unloading in both cycles. The value of ε was 1014μ in all cases. Here, when the round hole end strain range which is the first dominant factor of fatigue damage at the hole end portion of the circular hole 3A is obtained,
-Circular hole end strain range when the wedge means 4 is not used Δε ₀ = 1450 μ
・ Strain range Δε _w = 684 μ in the case of using the wedge means 4
By using the wedge means 4 and the pulley 541, the wedge means 4 follows the deformation of the circular hole 3A due to the tensile load acting on the base plate 1, and the circular hole end strain range Δε is increased by the wedge means 4. It has been found that the amount is significantly reduced to 47.2% of the case where no is used.

  A fatigue test that verifies the effect of the repair method of the fatigue crack and the repair member will be described as Example 3. In this example, the fatigue crack repair method and repair member according to the sixth embodiment described above were used. However, the torque load member was configured using a pulley instead of an arm.

Since the flat plate test piece used for the test has the same specifications as the flat plate test piece 1A used in Example 1, refer to FIG.
Moreover, since the wedge means used for the test is the same specification as the wedge means 4 used in Example 1, please refer to FIG.
Moreover, since the pulley (torque load member) used for the test is the same specification as the pulley 541 used in Example 2, please refer to FIG.

An electro-hydraulic servo type fatigue tester (manufactured by Shimadzu Corporation, dynamic capacity: 10 tonf) was used as the tester.
After attaching the flat plate test piece 1A to the hydraulic chuck of the testing machine, the wedge means 4 was attached to the circular hole 3A in the center. In this test, the amount of rotation of the pulley 541 and the moving distance of the weight 542 are larger than those in the second embodiment. Therefore, the length of the octopus thread wound around the pulley 541 and the path from the pulley 541 to the weight 542 are appropriately determined. It was adjusted.
The initial tightening amount of the bolt 230 is that the bolt 230 fixed to the pulley 541 and the pulley 541 are turned in the tightening direction from the state where the bolt 230 is completely relaxed, and the spherical bolt tip portion is the second slope part. Starting from the state in which resistance is felt when the bolt 230 is turned against the side surface of 220, the weight 542 for 430g is suspended from the tip of the octopus thread, and the pulley 541 is angled in the tightening direction. Rotated by 99.5 degrees. Since the pitch of the bolts 230 is 0.7 mm, the amount of axial movement of the bolts 230 due to the suspension of the weight 542 is 0.7 × 99.5 / 360 = 0.19 mm.

The fatigue test is performed under load control, with a nominal stress range Δσ _n = 27 MPa, a stress ratio R = 0 (full swing on the tension side), and a load frequency f = 3.6 Hz in a cross section without the notch 2A or the circular hole 3A. .

FIG. 26 shows the fatigue test results. In Example 3 in which the wedge means 4 was mounted in the circular hole 3A of the flat plate test piece 1A and the bolt 230 fixed to the pulley 541 was applied with a constant torque by the pulley 541 and the weight 542, the flat plate test was performed. compared with Comparative example 1 were tested only on a semi 1A, a circular hole edge strain range Δε is reduced to 28%, rupture life N _f was found to be significantly stretched and 9 times more.

  The present invention prevents the reoccurrence of cracks from stop holes and suppresses the development of recurrent cracks against fatigue cracks that occur in various structures such as ships, offshore structures, bridges, roads, vehicles, aircraft, and transportation / machine tools It can be used as a repair method and a repair member.

1 Base material plate (structure)
2 Fatigue crack 3 Stop hole 4 Wedge means 5 Automatic adjustment means 7 Wedge hole 10 Screw mechanism 11A First bolt shaft 11B Second bolt shaft 12 Nut 21 Torque load member (arm)
22 Loading mechanism (spring)
100 Screw mechanism 110 Pantograph type mechanism 120 Bolt mechanism 131 Torque load member (arm)
132 Loading mechanism (weight)
200 Screw mechanism 210 First slope part 220 Second slope part 230 Bolt 241 Torque load member (arm)
242 Loading mechanism (weight)
250 bowl-shaped portion 400 screw mechanism 410 first divided female screw component 420 second divided female screw component 430 taper bolt 440 tapered female screw portion 451 torque load member (arm)
452 Loading mechanism (weight)
450 First hook-like portion 460 Second hook-like portion 541 Torque load member (pulley)
542 Loading mechanism (weight)

Claims (21)

  Providing a stop hole at the tip of the fatigue crack and / or providing a wedge hole on a path other than the base and the tip of the fatigue crack with respect to the fatigue crack generated in the structure; And / or step 2 for fitting a wedge means having a variable wedge load into the wedge hole, and applying the wedge load that suppresses the stress fluctuation range of the structure at the hole end of the stop hole or the tip of the fatigue crack. A method for repairing a fatigue crack, comprising: step 3.   The method further comprises step 4 of adjusting the wedge load in order to follow the opening displacement of the hole portion of the stop hole and / or the opening displacement of the hole portion of the wedge hole and prevent the wedge means from loosening. The method for repairing a fatigue crack according to claim 1.   3. The fatigue according to claim 2, wherein the wedge load is adjusted within a range equal to or less than a maximum value of a stress acting on the structure at the hole end portion of the stop hole or the tip end portion of the fatigue crack. How to repair cracks.   The method for repairing a fatigue crack according to claim 3, wherein the maximum value of the stress is obtained by actual measurement and / or simulation.   The maximum value of the stress is obtained based on a maximum value of the opening displacement of the hole portion of the stop hole and / or a maximum value of the opening displacement of the hole portion of the wedge hole. 3. A method for repairing fatigue cracks according to 3.   The method for repairing a fatigue crack according to claim 2, wherein the adjustment of the wedge load is automatically performed using the wedge means.   The method for repairing a fatigue crack according to claim 1, wherein the wedge means is cooled and fitted into the stop hole and / or the wedge hole to apply the wedge load. .   The fatigue crack repairing method according to claim 1, wherein the steps 1 to 3 are performed from one side of the structure.   A repair member used in the method for repairing fatigue cracks according to claim 6, comprising: the wedge means; and an automatic adjustment means for automatically adjusting the wedge load of the wedge means. For repairing fatigue cracks.   The member for repairing a fatigue crack according to claim 9, wherein the wedge means has a screw mechanism.   A threaded first bolt shaft, a second bolt shaft threaded in the opposite direction to the first bolt shaft, and the first bolt shaft by rotation engaging with the first bolt shaft and the second bolt shaft. The screw mechanism is composed of a nut that expands and contracts the second bolt shaft, and the automatic adjustment means is composed of a torque load member that applies torque to the nut and a loading mechanism that applies load to the torque load member. The member for repairing a fatigue crack according to claim 10, wherein the member is a repair member.   The screw mechanism is composed of a pantograph type mechanism composed of a plurality of link parts, and a bolt mechanism that expands and contracts the pantograph type mechanism, a torque load member that applies torque to the bolt mechanism, and a load that is applied to the torque load member The member for repairing a fatigue crack according to claim 10, wherein the automatic adjustment means is constituted by a loading mechanism.   A first slope part having a slope, a second slope part having a slope that slides on the first slope part, and a bolt female screw formed on the first slope part that slides the second slope part The screw mechanism is constituted by a bolt fitted to the bolt, and the automatic adjustment means is constituted by a torque load member for applying torque to the bolt and a loading mechanism for applying a load to the torque load member. Item 15. A fatigue crack repair member according to Item 10.   A first divided female screw part having a tapered female screw, a second divided female screw part having a tapered female screw, and a tapered female screw part configured to be sandwiched between the first divided female screw part and the second divided female screw part; A torque load member configured to form the screw mechanism from a taper bolt that spreads the first divided female screw part and the second divided female screw part outward by rotating in a penetrating direction; and a torque load member that applies torque to the taper bolt; The member for repairing a fatigue crack according to claim 10, wherein the automatic adjustment means is constituted by a loading mechanism that applies a load to the member.   The member for repairing a fatigue crack according to claim 11, wherein the torque load member includes an arm.   The member for repairing a fatigue crack according to claim 11, wherein the torque load member is configured with a pulley.   17. The fatigue crack according to claim 11, wherein the torque load member applies a substantially constant torque to the nut, the bolt mechanism, the bolt, or the taper bolt. Repair material.   The fatigue crack repair member according to claim 17, wherein the load mechanism is configured with an elastic body.   The member for repairing a fatigue crack according to claim 17, wherein the load mechanism is configured with a weight.   20. The fatigue crack prevention device according to claim 9, wherein the wedge means includes a fall prevention means for preventing the wedge means from dropping from the stop hole and / or the wedge hole. Repair material. 21. The member for repairing a fatigue crack according to claim 20, wherein the drop-off preventing means is a hook-shaped portion provided in the wedge means for sandwiching the structure around the stop hole and / or the wedge hole. .