JP2019020309A - Monitoring system and method for crack repair part - Google Patents

Abstract

To monitor presence/absence of reduction of soundness of a crack repair part.SOLUTION: A crack repair part 103 has a configuration in which, a crack progress suppression structure 102 formed of insertion member attachment holes 104 and insertion members 105 is applied to a crack 101 of a plate material 100. An installation range 4 is set toward outside of the insertion member attachment hole 104 relative to an area where an opening width of an opening shape becomes maximum to a direction close to a tip of the crack 101 from positions being both end parts of the opening shape in a longitudinal direction on a peripheral edge of the insertion member attachment hole 104 in a first position of the order from a tip side of the crack 101. Based on a measurement result of a strain gauge 2a installed on the installation range 4, presence/absence of reduction of soundness caused by occurrence of a new crack from the insertion member attachment hole 104 is determined.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a crack repairing part monitoring system and a monitoring method for monitoring the presence or absence of soundness deterioration for a crack repairing part in which a crack in a metal object has been repaired.

  Cracks may occur in metal objects such as bridges, harbor structures such as cranes, and other steel structures due to fatigue due to repeated loads.

  It is required to repair the crack generated in such a metal object to suppress the progress (propagation).

  As a repair method that suppresses the growth of cracks that occur in this type of metal object, a crack growth suppression method that has been developed in the past has formed the following crack growth suppression structure where cracks have occurred in a metal object. (For example, refer to Patent Document 1).

  In the crack progress suppressing structure, an insertion member mounting hole having an opening shape extending in a direction intersecting with the crack is provided at a location where a crack of the metal object has occurred, and the insertion member is provided inside the insertion member mounting hole. It has a configuration that is inserted and fixed. Further, the insertion member mounting hole has an inner surface shape of an opening that is a curved surface shape or a shape formed by a curved surface and a continuous plane, and the opening shape is locked to the insertion member on both sides of the crack. It is provided with a locking portion.

  Furthermore, the engaging portion of the insertion member mounting hole is formed in a shape in which the opening width becomes narrower from the both end sides in the longitudinal direction of the opening shape toward the center portion side, and the insertion member has a cross-sectional shape on both end sides It has also been proposed in the past to have a shape that becomes narrower toward the center side.

  Thereby, according to the said crack progress suppression structure, when the load of the direction which opens the said crack acts on the said metal object, the load side part is latched by each latching | locking part of the said latching member attachment hole. Received by the inserted member. Thereby, in the metal object to which the crack progress suppressing structure is applied to the crack, the progress of the crack is suppressed by reducing the stress intensity factor width acting on the tip of the crack.

Japanese Patent No. 5883528

  The crack progress suppressing structure formed by the crack progress suppressing method disclosed in Patent Document 1 is effective as a repair for obtaining an effect of suppressing the progress of a crack generated in a metal object.

  By the way, the present inventors conducted a test for applying an excessive load in the direction of opening the crack using the test body, and as a result, a plurality of insertion member mounting holes in the crack of the metal object. In the crack growth suppressing structure provided with the insertion member, it has been found that stress concentration occurs in a specific region in the peripheral edge of the specific insertion member mounting hole. Furthermore, the present inventors have made a new crack from a specific region in a specific insertion member mounting hole where the stress concentration occurs as a result of a test to increase the load in the direction of opening the crack to be applied to the specimen. It was found that the occurrence of the cracks is more likely to occur than the phenomenon in which the original crack, which was the subject of progress suppression, progresses.

  Therefore, the present inventors have found that a crack in a metal object, where a crack is repaired to which the crack progress suppressing structure is applied, is a distortion in a specific region at the periphery of a specific insertion member mounting hole. Based on the change, it was found that the presence or absence of a decrease in the soundness of the crack repaired portion due to the occurrence of a new crack from the specific region can be detected.

  Therefore, an object of the present invention is to monitor a crack repair site that can detect the presence or absence of soundness deterioration in a crack repair site in which the crack progress suppressing structure is applied to a crack generated in a metal object. It is intended to provide a system and monitoring method.

  In order to solve the above-mentioned problems, the present invention provides an insertion member mounting hole provided at a location where a crack in a metal object has occurred and having an opening shape extending in a direction intersecting with the crack, and the insertion member mounting hole And the insertion member mounting hole has a curved surface shape or a shape formed by a curved surface and a plane continuous therewith, and the opening shape is formed on both sides of the crack. The crack repairing portion to which the crack progress suppressing structure configured to include a locking portion locked to the insertion member is applied, and the order from the front end side of the crack is the periphery of the first insertion member mounting hole. In a position toward the outside of the insertion member mounting hole from a region from both ends in the longitudinal direction of the opening shape to a portion where the opening width of the opening shape becomes maximum in the direction closer to the tip of the crack. Installation And strain gauges, the monitoring system crack repair point and a meter having a function of outputting the measurement result of the strain the strain gauges are connected to the gauge.

  The strain gauge is installed in a range of a distance of 1 mm to 30 mm toward the outside of the insertion member mounting hole from the region at the periphery of the insertion member mounting hole having the first order from the tip side of the crack. As a configuration.

  The strain gauge is configured to be provided at an angle of 45 degrees to 75 degrees along the crack with reference to a direction opposite to the front end side of the crack.

  The crack repairing portion further provided with a stop hole at a position corresponding to the tip of the crack is provided with another strain gauge on the opposite side of the crack with respect to the stop hole, and the measuring instrument is provided with the other strain. It has a function of outputting the measurement result of the gauge.

  A monitoring computer is provided, and the measuring instrument has a function of sending the measurement result to the computer via a communication network.

  Further, an insertion member mounting hole provided so as to have an opening shape extending in a direction intersecting with the crack at a place where a crack of the metal object has occurred, and an insertion member fixed by being inserted into the insertion member mounting hole The opening shape of the insertion member mounting hole is a curved surface shape or a shape formed by a curved surface and a plane continuous therewith, and the opening shape is engaged with the insertion member on both sides of the crack. About the crack repairing part to which the crack progress suppressing structure having a structure including a stopper is applied, the order from the tip side of the crack is the both ends in the longitudinal direction of the opening shape at the periphery of the first insertion member mounting hole. A strain gauge is used to measure the amount of change in strain at a position from the location to the location where the opening width of the opening shape becomes the maximum in the direction toward the tip of the crack toward the outside of the insertion member mounting hole. And monitoring methods of crack repair point to.

  According to the crack repairing part monitoring system and monitoring method of the present invention, it is possible to detect the presence or absence of a decrease in soundness at a repairing part in which a crack progress suppressing structure is applied to a crack generated in a metal object.

It is a schematic diagram showing a first embodiment of a crack repairing part monitoring system. It is a figure which expands and shows the principal part in FIG. It is a figure for demonstrating the crack growth suppression structure in a crack repairing part. It is a figure which shows the insertion member in a crack growth suppression structure. It is a figure for demonstrating the installation conditions of a strain gauge. It is a schematic diagram which shows 2nd Embodiment of a crack monitoring system.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 1 is a schematic diagram showing a first embodiment of a crack repair site monitoring system. FIG. 2 is an enlarged view showing a main part in FIG.

  3A and 3B are diagrams for explaining a structure for suppressing crack growth at a crack repairing location. FIG. 3A shows a state where a crack has occurred in the plate material, and FIG. 3B shows a state where the crack has occurred in the plate material. FIG. 3C is a schematic perspective view showing a state in which the member attaching hole is provided, and FIG. 3C is a state in which the inserting member is attached to the inserting member attaching hole. 4A and 4B show an insertion member used in the crack propagation suppressing structure, FIG. 4A is a view seen from one side of the insertion direction, and FIG. 4B is an AA direction arrow in FIG. FIG.

  FIG. 5 is a diagram for explaining the installation conditions of the strain gauges in the crack repairing part monitoring system. FIG. 5A shows a region where stress concentration occurs in the crack repairing part and a direction in which a new crack is likely to occur. FIG. 5B is a diagram showing the conditions of the strain gauge installation range and installation angle.

  The crack repairing part monitoring system according to the present embodiment is indicated by reference numeral 1 in FIGS. 1 and 2, and is, for example, a part where a crack 101 occurs in a plate member 100 constituting a steel structure as a metal object. Therefore, the crack 101 is applied to the crack repairing portion 103 repaired by the crack growth suppressing structure 102.

  The crack repairing part monitoring system 1 according to the present embodiment includes strain gauges 2a and 2b attached to the crack repairing part 103 in an installation range 4 set in accordance with conditions described later, and further connected to the strain gauges 2a and 2b. The measuring instrument 3 is provided.

  In addition, the crack repair location monitoring system 1 of the present embodiment is hereinafter simply referred to as the monitoring system 1 of the present embodiment for convenience of explanation.

  Here, first, the crack repairing portion 103 by the crack growth suppressing structure 102 to which the monitoring system 1 of the present embodiment is applied will be described.

  As shown in FIG. 3A, the crack growth suppressing structure 102 has an opening shape extending in a direction intersecting with the crack 101 as shown in FIG. An insertion member attachment hole 104 is provided, and as shown in FIG. 3C, the insertion member 105 is inserted and attached inside the insertion member attachment hole 104.

  The insertion member 105 is a plate-like member as shown in FIGS. In the insertion member 105, one direction indicated by an arrow in FIG. 4B is set as the insertion direction x into the insertion member attachment hole 104.

  Further, the insertion member 105 has a cross-sectional shape perpendicular to the insertion direction x, and the thickness of the end portions 106a and 106b is larger than the thickness of the central portion 107 as shown in FIG. It is supposed to be a shape. The cross-sectional shape perpendicular to the insertion direction x in the insertion member 105 is hereinafter referred to as the cross-sectional shape of the insertion member 105.

  The outer surfaces 108a and 108b of the portions 106a and 106b near both ends of the insertion member 105 are continuous curved surfaces. Furthermore, it is preferable that the curved surfaces that protrude outwardly on the outer surfaces 108a and 108b have a constant curvature. This is to match the curved shape provided at both ends in the longitudinal direction of the opening shape of the insertion member mounting hole 104 having a shape as shown by a two-dot chain line in FIG.

  Further, in the insertion member 105, the outer surfaces 109a and 109b on both sides of the central portion 107 constricted between the end portions 106a and 106b are continuous curved surfaces. This is to prevent the bent portion where the stress concentration easily occurs from being formed on the outer surfaces 109a and 109b of the central portion 107 so that the change in the plate thickness is continuous at the central portion 107 of the insertion member 105. It is.

  In view of the fact that the crack 101 to be repaired is the crack 101 of the plate member 100, the insertion member 105 is configured so that both end surfaces in the insertion direction x are planes perpendicular to the insertion direction x, as shown in FIG. Has been. Further, the dimension L in the insertion direction x of the insertion member 105 is equal to or larger than the plate thickness t (see FIG. 3A) of the plate member 100 in which the crack 101 is generated. It is preferable that it is set. This is because the insertion member 105 to be inserted into the insertion member mounting hole 104 of the plate member 100 can be disposed over the entire region of the plate thickness t of the plate member 100.

  As shown in FIG. 3B, the insertion member mounting hole 104 is a hole provided so that the opening shape extends in a direction intersecting with the crack 101 at a place where the crack 101 of the plate member 100 is generated.

  As shown by a two-dot chain line in FIG. 4A, the opening shape of the insertion member mounting hole 104 is such that the opening width of the central portion 110 in the longitudinal direction is narrower than the opening width on the side closer to both ends 111a and 111b. ing. The opening width of the central portion 110 is set to a size that can accommodate the central portion 107 of the insertion member 105 and is smaller than the plate thickness of the both end portions 106 a and 106 b of the insertion member 105.

  The portions 111 a and 111 b near the both ends in the longitudinal direction of the opening shape of the insertion member mounting hole 104 are configured to accommodate the portions 106 a and 106 b near the both ends of the insertion member 105.

  In the opening shape of the insertion member mounting hole 104, the portion where the opening width becomes narrower from the both ends 111a and 111b toward the central portion 110 is a pair of locking portions s, and each locking portion s has a crack 101. It is formed on both sides.

  Thus, in a state where the insertion member 105 is inserted into the insertion member attachment hole 104, the portions 106a and 106b near the both ends of the insertion member 105 are locked to the respective locking portions s of the insertion member attachment hole 104. Therefore, when a load in the direction of opening the crack 101 acts on the plate member 100, the load is transmitted to the insertion member 105 from each locking portion s of the insertion member mounting hole 104 provided on both sides of the crack 101. Can do. For this reason, in the plate member 100, the deformation in the opening direction of the crack 101 is restrained by the insertion member 105 attached to the insertion member attachment hole 104.

  The insertion member mounting hole 104 has an opening shape that is a continuous curved surface, that is, a smooth curved surface without a bent portion, or a shape that includes a curved surface and a continuous plane. As a result, the insertion member mounting hole 104 is less likely to cause stress concentration at a part of the peripheral edge of the opening shape. Furthermore, it is preferable that the curved surfaces that protrude outward in the longitudinally opposite ends 111a and 111b of the opening shape of the insertion member mounting hole 104 are curved surfaces having a certain curvature. This is to make it more difficult for stress concentration to occur in the portions 111a and 111b near the both ends in the longitudinal direction of the opening shape.

  Note that the opening shape of the insertion member mounting hole 104 is slightly larger than the cross-sectional shape of the insertion member 105 so that the gap between the inner surface of the insertion member mounting hole 104 and the outer surface of the insertion member 105 is as small as possible. It is suitable to set to. This is because the thickness of the layer of the adhesive 112 that is interposed between the opposing surfaces of the insertion member mounting hole 104 and the insertion member 105 to reduce the thickness of the insertion member mounting hole 104 and the insertion member 105 is minimized. This is to make it possible to transfer the load between the two. 3C, FIG. 4A, and FIG. 2, the space between the insertion member mounting hole 104 and the insertion member 105 is shown enlarged for convenience of illustration (the same applies to FIG. 5 described later).

  The repair by the crack progress suppressing structure 102 for the crack 101 generated in the plate material 100 is first performed as shown in FIGS. 1, 2, 3 (a), (b), and (c). The insertion member mounting hole 104 is provided at the generated position in an arrangement in which the opening shape (see FIG. 4A) extends in a direction intersecting the crack 101, preferably in a direction perpendicular to the crack 101.

  At this time, in order to arrange the insertion member 105 to be inserted into the insertion member attachment hole 104 evenly on both sides of the crack 101, the insertion member attachment hole 104 intersects the crack 101 near the center in the longitudinal direction of the opening shape. It is provided as follows.

  Next, the insertion member 105 is inserted into the insertion member mounting hole 104 in a state where an adhesive (structural adhesive) 112 is applied to the surface of the insertion member 105 that contacts the inner surface of the insertion member mounting hole 104. The adhesive 112 may be applied to the inner surface of the insertion member mounting hole 104, or may be applied to both the outer surface of the insertion member 105 and the inner surface of the insertion member mounting hole 104. Thereafter, the adhesive 112 is cured.

  As a result, the crack 101 was repaired by the crack growth suppressing structure 102 attached in a state where the insertion member 105 was fixed to the inside of the insertion member attachment hole 104 by adhesion at the place where the crack 101 occurred in the plate member 100. A crack repair location 103 is formed.

  It should be noted that the number of the insertion member mounting holes 104 and the insertion members 105 provided for the crack 101 may be set as appropriate according to the extension dimension of the crack 101 and the load acting on the portion of the plate member 100 where the crack 101 exists. Good. FIG. 1 shows an example of a configuration in which a plurality of insertion member mounting holes 104 and insertion members 105 are provided for one crack 101, but the number of insertion member mounting holes 104 and insertion members 105 provided for the crack 101. The arrangement interval is for convenience of illustration and does not reflect the actual number or arrangement interval.

  When a plurality of insertion member mounting holes 104 and insertion members 105 are provided for one crack 101, the number of arrangement and the arrangement interval are set by a method using the same analysis as the method shown in Patent Document 1. That's fine.

  In the present embodiment, the crack repairing portion 103 is further provided with a stop hole 113 at a position corresponding to both ends of the crack 101 in the plate member 100 as shown in FIGS.

  Next, the test conducted by the present inventors will be described.

  The present inventors conducted a test in which an excessive load is applied in the direction of opening the crack 101 using a test body (not shown) having a configuration in which the crack growth suppressing structure 102 having the above-described configuration is applied to the crack 101. . As a result, when a plurality of insertion member mounting holes 104 and a plurality of insertion members 105 are provided in the longitudinal direction of the crack 101, as shown in FIG. In the mounting hole 104, it has been found that stress concentration occurs in the hatched region 5 at the peripheral edges of the ends 111a and 111b. The stress concentration in this region 5 is caused by the other part of the periphery of the opening part of the same insertion member attachment hole 104 or the opening part of another insertion member attachment hole 104 whose order from the tip side of the crack 101 is second or later. The stress concentration is larger than that at the periphery.

  Further, the region 5 where the stress concentration occurs in the specific insertion member mounting hole 104 is located at the periphery of both end portions 111a and 111b, from the portions 6 that are both ends in the longitudinal direction of the opening shape, near the tip of the crack 101. It turned out that it is an area | region to the location 7 where the opening width of an opening shape becomes the maximum toward a direction.

  Furthermore, the present inventors conducted a test for increasing the load in the direction of opening the crack 101 to be applied to the specimen. As a result, it has been found that a new crack 8 as shown by a one-dot chain line in FIG. 5A is generated from the region 5 where stress concentration occurs in the specific insertion member mounting hole 104. It has also been found that the generation of a new crack 8 starting from the region 5 where the stress concentration occurs is more likely to occur than the original crack 101 that has been repaired by the application of the crack growth suppressing structure 102.

  In addition, the new crack 8 is mainly generated in a direction shifted by 30 degrees with respect to the direction toward the tip side of the crack 101 along the original crack 101, and an angle shift from the main direction is generated. Was found to fall within an angular range of about ± 10 degrees.

  In view of the above test results, in the monitoring system 1 of the present embodiment, the installation range 4 of the strain gauge 2a is set as shown in FIG. This installation range 4 is a region 5 where stress concentration occurs at the peripheral edges of the portions 111a and 111b near the both ends of the insertion member mounting hole 104 in the first order from the tip side of the crack 101, that is, both end portions in the longitudinal direction of the opening shape. From the area 6 to the position closer to the tip of the crack 101, the distance from the region up to the position 7 where the opening width of the opening shape becomes the maximum is 1 mm to 30 mm toward the outside of the insertion member mounting hole 104. The range is set.

  The reason why the installation range 4 of the strain gauge 2a is set to a range of 1 mm to 30 mm from the region 5 where stress concentration occurs at the periphery of the insertion member mounting hole 104 is as follows.

  That is, in general, in a metal object, a change in strain occurs due to the occurrence of a crack, but the effect of the change in strain becomes smaller as the distance from the crack generation point increases. Therefore, when using a strain gauge to detect a change in strain caused by the occurrence of a crack that occurs in a metal object, the accuracy of detection is improved if the position of the strain gauge is more than 30 mm away from the location of the crack. It is because it is not so preferable at the point which falls. On the other hand, when attaching to a metal object, the strain gauge needs to be attached using an adhesive or the like, so it is substantially difficult to install the strain gauge at a position less than 1 mm from the edge of the metal object. .

  In general, when the presence or absence of a crack is detected with a strain gauge, it is preferable to set the angular orientation of the strain gauge in a direction orthogonal to the crack that is assumed to occur. However, when the strain gauge is actually attached to a metal object, it is difficult to precisely match the angle orientation of the strain gauge to the target value, and an angular deviation of about 5 degrees may occur.

  Therefore, in the monitoring system 1 of the present embodiment, the angular posture of the strain gauges 2a and 2b installed in the installation range 4 is a direction shifted by 30 ° ± 10 ° from the direction along the crack 101 toward the tip side of the crack 101. The target is set to a direction that is 120 degrees ± 15 degrees apart from the direction that is orthogonal to the direction of the crack 101, that is, a direction that is 120 degrees ± 10 degrees away from the direction that faces the tip of the crack 101. . Note that the angle posture of the strain gauge 2a is 45 ° to 75 ° when the direction along the crack 101 and opposite to the tip side of the crack 101 is used as a reference. In this case, when considering from the point of the main direction where the new crack 8 is generated, the angle posture of the strain gauges 2a and 2b installed in the installation range 4 is preferably along the crack 101 on the tip side of the crack 101. The direction deviates by 120 degrees from the facing direction, that is, the direction deviates from the direction opposite to the tip side of the crack 101 along the crack 101 by 60 degrees.

  Therefore, as shown in FIGS. 1 and 2, the monitoring system 1 of the present embodiment has cracks at both ends in the longitudinal direction of the opening shape of the insertion member mounting hole 104 with the first order from the tip side of the crack 101. The strain gauge 2a is provided in the installation range 4 that is closer to the distal end side of 101 with a set angular posture.

  In the strain gauge 2a, if the part that actually detects the strain, such as a resistance wire or a resistance foil, is in the installation range 4, the outer peripheral part that does not participate in the strain detection protrudes from the installation range 4. Of course, it is also good.

  Furthermore, the monitoring system 1 of the present embodiment has a means for detecting when the original crack 101 has advanced again from the stop hole 113, as shown in FIGS. It is preferable that the strain gauge 2b is provided in a range of a distance of 1 mm to 30 mm on the side opposite to the crack 101 with respect to the provided stop hole 113.

  The angular posture of the strain gauge 2b is set in a direction shifted by 90 ° ± 5 ° with respect to the direction along the crack 101 toward the tip side of the crack 101.

  The strain gauge 2a and the strain gauge 2b are both selected from strain gauges having a linear expansion coefficient that is equal to or corresponding to the linear expansion coefficient of the plate member 100, so that heat output (apparent strain due to temperature change) is used. It is trying to suppress.

  The measuring instrument 3 has a function of outputting a resistance change in the connected strain gauge 2a and the strain gauge 2b as a measurement result of the strain change amount.

  The measurement result output by the measuring instrument 3 is, for example, connected to a portable terminal 9 such as a personal computer or a tablet carried by an operator (not shown) as shown by a two-dot chain line in FIG. The wireless communication may be performed.

  When monitoring the crack repairing portion 103 by the crack growth suppressing structure 102 in the plate member 100 using the monitoring system 1 of the present embodiment having the above-described configuration, the operator uses the portable terminal 9 to set the set time. The measurement results of the strain gauge 2a and the strain gauge 2b output from the measuring instrument 3 at intervals are received.

  And based on the time series of the measurement result by the strain gauge 2a, when the measurement result of the strain change amount by the strain gauge 2a has not changed significantly, or the change applicable to the pattern at the time of the crack occurrence has occurred. If not, it can be determined or estimated that there is no new crack 8 (see FIG. 5A) from the insertion member mounting hole 104 at the crack repairing portion 103.

  Moreover, based on the time series of the measurement result by the strain gauge 2b, when the measurement result of the strain change amount by the strain gauge 2b has not changed significantly, or the change applicable to the pattern at the time of crack occurrence has occurred. If not, it can be determined or estimated that the original crack 101 has not progressed from the stop hole 113 at the crack repair location 103.

  Therefore, in the monitoring system 1 of the present embodiment, if there is no significant change in the measurement results of the strain gauge 2a and the strain gauge 2b, or if there is no change applicable to the pattern at the time of crack occurrence, It can be determined that the soundness of the repair location 103 has not deteriorated.

  On the other hand, based on the time series of the measurement results by the strain gauge 2a, for example, when the measurement result of the strain change amount by the strain gauge 2a changes significantly, or there is a change that matches the pattern at the time of crack occurrence. If it occurs, it can be determined or estimated that a new crack 8 (see FIG. 5A) has occurred from the insertion member mounting hole 104 at the crack repairing portion 103.

  Therefore, in this case, in the monitoring system 1 of the present embodiment, it can be determined that the soundness of the crack repairing portion 103 has deteriorated due to the occurrence of a new crack 8 from the insertion member mounting hole 104. .

  Further, based on the time series of the measurement results by the strain gauge 2b, for example, when the measurement result of the strain change amount by the strain gauge 2b changes significantly, or there is a change that matches the pattern at the time of crack occurrence. If it occurs, it can be determined or estimated that the original crack 101 has re-progressed from the stop hole 113 at the crack repair location 103.

  Therefore, in this case, in the monitoring system 1 of the present embodiment, it can be determined that the soundness of the crack repairing portion 103 has deteriorated due to the re-progress of the original crack 101 from the stop hole 113.

  As described above, according to the monitoring system 1 of the present embodiment, it is possible to monitor whether or not the soundness of the crack repairing portion 103 to which the crack progress suppressing structure 102 is applied is deteriorated.

  Further, in the monitoring system 1 of the present embodiment, information on the region 5 where stress concentration occurs in the crack repairing portion 103 obtained by the test, and information on the position and angle where a new crack 8 is expected to occur from the region 5 are obtained. Based on the above, the arrangement of the strain gauges 2a is determined. Therefore, even when the crack repairing portion 103 including three or more insertion member mounting holes 104 and the insertion member 105 is to be monitored, the monitoring system 1 of the present invention is as shown in FIG. The strain gauges 2a may be provided only at both ends in the longitudinal direction of the opening shape of the insertion member mounting hole 104 in which the order from the both ends of the crack 101 is first. Therefore, since the monitoring system 1 of this embodiment does not need to provide a strain gauge corresponding to all the insertion member mounting holes 104 in the crack repairing place 103, the number of strain gauges 2a used can be reduced. It is possible to simplify the device configuration by reducing the number of devices constituting the device.

[Second Embodiment]
FIG. 6 is a schematic view showing a second embodiment of the crack repairing part monitoring system.

  In FIG. 6, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in FIG. 6, the crack repair site monitoring system 1 </ b> A of the present embodiment has a configuration similar to that of the first embodiment, and the measuring instrument 3 is a portable terminal that the operator carries the measurement results of the strain gauges 2 a and 2 b. In place of the configuration for outputting to the network 9, the measuring instrument 3 is connected to a communication network 10 such as the Internet at all times or at a set time interval, and a remote monitoring center or the like via the communication network 10 The computer 11 for monitoring provided in 1 is configured to have a function of sending the measurement results of the strain gauges 2a and 2b.

  The monitoring computer 11 has a significant change in the function of monitoring the time series of the measurement result by the strain gauge 2a and the time series of the measurement result by the strain gauge 2b, and the measurement result of the strain change amount. In this case, when there is a change that matches the pattern at the time of occurrence of a crack, a function of generating a signal (alarm) that the soundness of the crack repairing portion 103 has been reduced may be provided.

  As in the first embodiment, the crack repairing part monitoring system 1A according to the present embodiment having the above-described configuration also monitors whether or not the soundness of the crack repairing part 103 to which the crack progress suppressing structure 102 is applied is deteriorated. And the same effects as those of the first embodiment can be obtained.

  In each of the above embodiments, as an application target of the crack repairing part monitoring system of the present invention, the repairing part of the crack 101 generated in the plate member 100 constituting the steel structure is exemplified. Of course, the present invention may be applied to a repaired portion of a crack 101 generated in a welded portion obtained by butt welding plate members arranged in the same plane, or a crack 101 extending from the welded portion to one or both plate members.

  Furthermore, the crack repairing part monitoring system according to the present invention is, for example, a joint (welded part) between a lower surface of a deck plate that becomes a corner portion of a bridge and an upper edge of a U-rib arranged below the deck plate. The present invention may be applied to the crack repairing portion 103 by the crack progress suppressing structure 102 of the crack 101 generated at the bent portion in a simple metal object.

  In this case, the strain gauge 2a has the same installation range 4 and angular posture as shown in FIG. 5B when viewed from a direction perpendicular to the surface of the metal object in which the insertion member mounting hole 104 is provided. You may make it to decide.

  When the tip of the crack 101 exists in the welded part or in the bent part of the metal object, a stop hole 113 is provided at the tip of the crack 101 at the crack repairing portion 103. I can't. Therefore, in such a case, the crack repair site monitoring system of the present invention may be configured without the strain gauge 2b.

  In addition, the present invention is not limited to each of the above embodiments, and the crack repairing site monitoring system of the present invention is a plate material 100 or any metal object other than a bridge deck plate and U rib. Needless to say, the present invention may be applied to the crack repairing portion 103 in which the crack 101 is repaired by the crack progress suppressing structure 102.

  The shape in the insertion direction x of the insertion member 105 inserted and attached to the insertion member attachment hole 104 at the crack repairing location 103 is not particularly limited.

  The insertion member mounting hole 104 may not be a through hole in a metal object.

  Of course, various modifications can be made without departing from the scope of the present invention.

2a, 2b Strain gauge, 3 measuring instrument, 4 installation range, 5 areas, 6 places, 7 places, 10 communication network, 11 monitoring computer, 100 plate material (metal object), 101 crack, 102 crack growth suppressing structure, 103 crack repairing part, 104 insertion member mounting hole, 105 insertion member, 111a, 111b part near both ends, 113 stop hole, s locking part

Claims (6)

An insertion member mounting hole provided so as to have an opening shape extending in a direction crossing the crack, and an insertion member fixed by being inserted into the insertion member mounting hole, at a location where a crack of the metal object has occurred. The opening shape of the insertion member mounting hole is a curved surface shape, or a shape formed by a curved surface and a plane continuous therewith, and the opening shape is a locking portion that is locked by the insertion member on both sides of the crack. About the crack repairing part to which the crack growth restraining structure with the structure comprising
The opening width of the opening shape extends from the position where the opening shape is located at both ends in the longitudinal direction at the periphery of the first insertion member mounting hole in the order from the tip side of the crack toward the tip of the crack. A strain gauge installed at a position toward the outside of the insertion member mounting hole from the area up to the maximum point,
And a measuring instrument having a function of connecting the strain gauge and outputting the measurement result of the strain gauge. The strain gauge is installed in a range of a distance of 1 mm to 30 mm toward the outside of the insertion member mounting hole from the region at the periphery of the insertion member mounting hole having the first order from the tip side of the crack. The crack repair site monitoring system according to claim 1. The strain gauge is provided at an angle of 45 degrees to 75 degrees along the crack, with reference to a direction opposite to the tip side of the crack.
The crack repair site monitoring system according to claim 1 or 2. About the crack repairing portion further provided with a stop hole at a position corresponding to the tip of the crack,
With respect to the stop hole, another strain gauge is provided on the side opposite to the crack,
The crack repair site monitoring system according to any one of claims 1 to 3, wherein the measuring instrument has a function of outputting a measurement result of the another strain gauge. Equipped with a computer for monitoring,
The crack repair site monitoring system according to any one of claims 1 to 4, wherein the measuring instrument has a function of sending the measurement result to the computer via a communication network. An insertion member mounting hole provided so as to have an opening shape extending in a direction crossing the crack, and an insertion member fixed by being inserted into the insertion member mounting hole, at a location where a crack of the metal object has occurred. The opening shape of the insertion member mounting hole is a curved surface shape, or a shape formed by a curved surface and a plane continuous therewith, and the opening shape is a locking portion that is locked by the insertion member on both sides of the crack. About the crack repairing part to which the crack growth restraining structure with the structure comprising
The opening width of the opening shape extends from the position where the opening shape is located at both ends in the longitudinal direction at the periphery of the first insertion member mounting hole in the order from the tip side of the crack toward the tip of the crack. A crack repairing site monitoring method, characterized in that a strain gauge measures the amount of strain change at a position toward the outside of the insertion member mounting hole from the region up to the maximum location.

Images