JP4685574B2 - High strength bolt friction joints and building steel structures - Google Patents

Description

The present invention relates to a high-strength bolt friction joint of steel members used for column joints, beam joints, and other joints of plate elements, and a construction steel structure when building a construction steel structure that requires high earthquake resistance. It is about.
Here, the friction joint, for example, as shown as a general example in FIG. 9, by superposing the plate member 1 _1, 1 ₂ of the tip portion, fastened with high strength bolts 2, the plate member 1 by the axial clamping force _1, 1 is the stress at the bonding method for transmitting by the frictional force generated between the _2, stress transmitted to the joint has a bolt shaft and perpendicular, a junction in the category of so-called shear type junction.
In addition to friction bonding, shear type bonding includes support bearing, but this does not introduce a tightening axial force to the bolt, and the bearing resistance of the plate member at the bolt hole and the shear resistance of the bolt shaft. The friction welding is different from the support pressure welding in that the fastening axial force is introduced and the stress transmission method.

In the field of high-strength bolt friction welding of steel members for building construction steel structures, there is an increasing demand for a reduction in the number of bolts from the viewpoint of compacting joints, labor and labor for tightening work. In order to respond to the above, development has been made to increase the strength of high-strength bolts, increase the load transmission capacity per one, and reduce the number of bolts.
Conventionally, high-strength bolts mainly consist of high-strength bolts with a tensile strength of 1000 MPa class (clamping axial force: 1000 MPa × threaded portion effective cross-sectional area × 0.74). However, high-strength bolts of 1400 MPa class (clamping axial force: 1400 MPa × thread portion effective cross-sectional area × 0.74) have been used.
Here, the screw effective cross-sectional area is an effective cross-sectional area of the screw defined by JIS B 1082-1987, and is calculated by the equation (1).
A _s = π / 4 · {(d ₂ + d ₃ ) / 2} ² (1)
Here, A _s : Effective cross-sectional area of screw d ₂ : Reference diameter of effective diameter of screw of high-strength bolt, and diameter of virtual cylinder where width of screw groove is equal to width of screw thread d ₃ : High Standard dimensions of thread bolt diameter of force bolt (see Fig. 10).

Thus, high-strength bolts have advanced considerably in strength, but as high-strength bolts used in the field of building steel structures, the high-strength bolts have not yet reached a level that can be sufficiently satisfied. Is hard to say. By increasing the strength of high-strength bolts to about 1700-2600 MPa, which is sufficiently possible at the current level of technology, the number of bolts used can be further reduced, the joints can be made more compact, and the work for tightening and tightening bolts can be reduced. Labor saving is possible. However, in the case of friction joining that uses high tension by introducing high tension to a high strength bolt, the possibility of delayed fracture increases as the strength of the high strength bolt increases to 1100 MPa or higher. Is required.
Here, delayed fracture is a phenomenon in which fracture occurs suddenly after a lapse of time after a tensile load is applied to a metal material.

In Technical Document 1, a material that has improved delayed fracture resistance by adding alloying elements to the material of high-strength bolts is used, and stress concentration, which is considered to be one of the causes of delayed fracture, is reduced by improving the screw shape. Techniques for taking measures are disclosed. However, even if the strength level is 1400 MPa class (introduction tension: 1400 MPa × thread portion effective cross-sectional area × 0.74), it is still not a satisfactory level.
On the other hand, friction welding is often used in building steel structures, but in building seismic design, it is used in the allowable strength determined from the introduction tension (design for small and medium earthquakes (called primary design). )) And the maximum strength determined from the material strength of the high strength bolt (used in designing against large earthquakes, the "maximum shear strength" when the high strength bolt undergoes shear failure). The joint design is performed from two surfaces.
Therefore, when the number of bolts is determined in the design for a large earthquake, the number of bolts can be reduced by strengthening the “maximum shear strength” (hereinafter referred to as “maximum strength”).

Patent Document 1 discloses a one-side bolt having a structure in which a sheath material (here, a sleeve) is inserted into a bolt hole as in the present invention (see FIGS. 1 and 2). However, “the sleeve body has a soft sleeve that is softer than other parts near the tip, and this soft sleeve can be buckled in an expanded state by applying an axial compressive load to the sleeve. It shall be (Refer to paragraph [0006] lines 9 to 12), and the sleeve itself is made soft and buckled at the time of bolt tightening, and is deformed like a hook for bolt tightening on the bolt head side having a smaller diameter than the bolt hole. A portion (larger than the bolt hole diameter) is formed.
Therefore, the present invention for improving the maximum proof stress of the joint portion by shear resistance using a sheath material made of a high strength material having a material length shorter than the tightening length of 1700 to 2600 MPa has no object, structure, or effect. It is different.
Further, Patent Document 2 discloses a fastener having a structure in which a sheath material (in this case, a cylindrical member) is inserted into a bolt hole as in the present invention (see FIGS. 1, 2, and 3). ). However, “The cylindrical member 24 is made of an iron-based material such as S20C (see the 30th to 31st lines of the embodiment). In the embodiment, the buckling tube 51 and the sleeve 44 are provided integrally. (Refer to the 48th to 49th lines of the embodiment)], and this buckling cylinder is made of an S20C material having a strength as low as about 500 MPa, and has a smaller diameter than the through hole (bolt hole) by buckling at the time of bolt fastening. An engaging portion (a diameter larger than the diameter of the through hole) for fastening the bolt is formed on the bolt head side.
Therefore, the material length is shorter than the tightening length, the sheath material made of a high strength material of 1700 to 2600 MPa is used, and the purpose, configuration and effect are completely different from the present application which improves the maximum proof stress of the joint portion by shear resistance. To do.
Performance of Super High-Strength Bolts with an Ultimate Strength of 1400 N / mm2 Class, Third International Symposium on SteelStructure, 200. JP 11-159509 A Japanese Examined Patent Publication No. 6-27525

  The present invention makes it possible to reinforce the maximum proof stress as a joint when using a high-strength bolt with low tensile strength that is less likely to cause delayed fracture. A high-strength bolt friction joint of steel members and a construction steel structure that can realize labor saving at low cost.

The present invention has been made to solve the above-described problems, and the gist thereof is as follows.
(1) A high-strength bolt friction joint of a steel member that constructs a building steel structure using a high-strength bolt having a tensile strength of 700 to 1600 MPa, and inserted into a bolt hole of a member to be joined A sheath material having a material length shorter than the fastening length for the member to be joined and a tensile strength of 1700 to 2600 MPa is inserted between the bolt shaft and the bolt hole so that no stress is applied at all times. Therefore, when the stress exceeding the allowable strength acts on the joint portion and the shear force acts on the shaft portion of the high-strength bolt, the high-strength bolt with the high-strength characteristics of the sheath material is avoided. A high-strength bolt friction joint of a steel member, wherein the shear strength of the steel member is reinforced and thereby the maximum shear strength of the joint is reinforced .
(2) A plate washer having a thickness equal to or greater than that of the washer is interposed between the washer inserted in the high-strength bolt and the member to be joined, and the fastening axial force is transmitted to the member to be joined and friction-joined. The high-strength bolt friction joint portion of the steel member according to (1).
(3) The sheath material is a sheath material composed of a short tube, a sheath material composed of a molded body arranged so as to be opposed to both sides of the high-strength bolt in a shape in which the short tube is halved, and a plate is molded into a cylindrical shape The high-strength bolt friction joint portion of the steel member according to (1) or (2), wherein the sheath member is a sheath material made of a molded body that does not join the end faces.
(4) The length of the sheath material is 0.6 to 0.9 times the thickness of the member to be joined in a state where the tightening axial force is introduced, and the thickness of the sheath material is 1 to 5 mm. The high-strength bolt friction joint part of the steel member according to any one of the above (1) to (3).
(5) An architectural steel structure having at least one high-strength bolt friction joint of the steel member according to any one of (1) to (4).
The “sheath material” as used in the present invention means a short tube, a molded plate that is bent into a tubular shape and does not join the end faces, or a shape obtained by dividing these vertically, and these are hereinafter referred to as “ Collectively referred to as “sheath material”. The steel member in the present invention means “steel member alone”, and the construction steel structure is obtained by assembling an “intermediate structure” formed by assembling steel members or a plurality of these intermediate structures. Say things.

In the high-strength bolt friction joint part of the steel member of the present invention, the high-strength bolt is reinforced to reinforce the maximum strength as a joint part by inserting a sheath material having a material length shorter than the tightening length to the high-strength bolt. can do. For example, when a 700 to 1600 MPa high-strength bolt that is less likely to cause delayed fracture is used, the tensile strength is greater than 1700 to 2600 MPa, and the length is shorter than the fastening length. By inserting the sheath material so that stress is not applied at all times, the occurrence of delayed fracture can be avoided, and the reinforcement function of the high-strength bolt can be exhibited only when the maximum proof stress as a joint portion is exhibited. .
Therefore, it is easy to avoid the occurrence of delayed fracture in the high-strength bolt and the sheath material, and the high-strength bolt alone ensures the maximum yield strength of 700 to 1600 MPa class, while the maximum strength is achieved by the function of the sheath material. It can be increased beyond the maximum yield strength of a single bolt.
As a result, when the number of bolts is determined in the design for a major earthquake, the number of bolts can be reduced to reduce the size, labor, and labor of tightening work at a low cost. When applied as a high-strength bolt friction joint of a member, it has a remarkable effect.
In addition, from the viewpoint of enhancing the reinforcing function of the sheath material, when the thickness of the sheath material is increased, the bolt hole diameter of the material to be joined may be larger than the head diameter of the high strength bolt or the outer diameter of the washer, Even if a high-strength bolt is tightened, a compressive force is applied to the sheath material, so that the material to be joined cannot be tightened.In such a case, a plate washer having a thickness and area larger than the washer is interposed. The fastening axial force can be reliably transmitted to the material to be joined to ensure the frictional force, and the same remarkable effect can be obtained.

The high-strength bolt friction joint of the steel member of the present invention uses, for example, a high-strength bolt with a tensile strength that has a low risk of delayed fracture even when a high tension is constantly applied. By inserting a sheath material having a short length and a strength higher than that of the high strength bolt, the high strength bolt is reinforced to reinforce the maximum proof stress as a friction joint. This friction joint basically has a tightening axial force of a high-strength bolt, 0.74 times the value obtained by multiplying the tensile strength of the bolt material by the effective cross-sectional area of the thread, as with conventional high-strength bolts. It is obtained by friction bonding with a tensile force of a degree.
In the present invention, for example, when a high strength bolt having a tensile strength of 700 to 1600 MPa is used, it is made of a high strength material having a tensile strength of 1700 to 2600 MPa, which has a great risk of delayed fracture when a high tension is always applied. A sheath material shorter than the tightening length is inserted so that high tension is not applied at all times to avoid delayed fracture, and slippage occurs due to stress exceeding the allowable yield strength determined from the introduced tension acting on the joint. However, when the joint part is in a bearing or shear state, the high strength characteristics of the sheath material function to reinforce the high-strength bolt (especially shear strength reinforcement), and the maximum tensile strength as the joint is the conventional tensile strength. The present invention solves the above-mentioned problem by making it possible to reinforce it more than when using a 700-1600 MPa class high-strength bolt.

The high-strength bolt having a tensile strength of 700 to 1600 MPa, for example, used in the present invention is a high-strength bolt having a strength level that can be evaluated as a high-strength bolt that can suppress the occurrence of delayed fracture at present. With a high-strength bolt of less than 700 MPa, it is not possible to introduce a tightening axial force that can ensure a sufficient sliding strength, and even if the maximum strength of the high-strength bolt is increased, a sufficient joint strength cannot be secured as a friction joint, It causes a significant increase in the number of bolts and becomes inefficient. When a high-strength bolt exceeding 1600 MPa is used, there is a concern about the occurrence of delayed fracture, so the pressure was set to 700 to 1600 MPa.
In addition, the sheath material having a tensile strength of 1700 to 2600 MPa is a necessary condition for remarkably strengthening the maximum proof stress as a joint as compared with a conventional high strength bolt of 700 to 1600 MPa class. .
In addition, although the high strength bolt friction joint part of this invention is applied as a high strength bolt friction joint part of a steel frame member, according to the joint part characteristic requested | required of a joining part, it is only to some joining parts. It is also possible to construct an architectural steel structure by using joints other than the present invention in combination.
High-strength bolt friction joining is frequently used in building steel structures. In building seismic design, the allowable strength determined from the introduction tension and the maximum strength determined from the material strength of the high-strength bolt are 2 The joint design is done from one side. Therefore, when the number of bolts is determined in the design for a large earthquake, the number of bolts can be reduced by enhancing the maximum proof stress.

In particular, the inventors focused on strengthening the “maximum proof stress” as a joint, and the “slip proof strength” secured the same level as before by using conventional 700 to 1600 MPa class high strength bolts. The idea was to reinforce this “high strength bolt” by other means to strengthen the “maximum proof stress” as a joint.
That is, for example, when a high-strength bolt with a tensile strength of 1700 MPa or more is used, the possibility of delayed fracture will increase if it is always used with high tension applied. Therefore, the effect of increasing the strength cannot be fully enjoyed. In the case of high-strength bolt friction welding, based on the knowledge that the maximum proof stress as a joint is ultimately governed by the shear strength of the high-strength bolt,
(1) The conventional tensile strength that is less likely to cause delayed fracture when the tightening axial force is approximately 0.74 times the value obtained by multiplying the tensile strength of the bolt material by the effective sectional area of the thread. A 700-1600 MPa class high strength bolt is used.
(2) The shear strength of the high-strength bolt is higher than that of the high-strength bolt used. For example, a high-strength material of 1700MPa class or higher, which is likely to cause delayed fracture, is used under conditions that do not cause delayed fracture. The maximum proof stress as a joint portion is increased by reinforcing them.
As a result of repeated experimentation (examination), if the requirements of the present invention are satisfied, the allowable proof stress is ensured to be equal to or higher than that in the case of using a conventional 700 to 1600 MPa class high strength bolt. The maximum proof stress as a part can be strengthened more than when a high strength bolt having a tensile strength of 700 to 1600 MPa is used, and it has been confirmed that the above problems can be advantageously solved.

Fig.1 (a) shows the high strength bolt friction structure (example) of this invention with a schematic conceptual diagram. Here, the materials to be joined are the thick steel plates 1 ₁ , 1 ₂ , and the high strength bolts 2 having a tensile strength of 700 to 1600 MPa are overlapped by superimposing both joints, and on the head side and the nut 3 side. This shows the case where one surface frictional joining is performed with a washer 4 interposed, and the frictional force due to the introduction of the tightening axial force acts mainly between the joining surfaces of the thick steel plates 1 ₁ , 1 ₂ (thick steel plates 1 ₁ , 1 also act) and the like between the _second outer surface and the washer 4, when a large stress that exceeds the frictional force to the joint portion is applied, the steel plate 1 ₁ slip _occurs, 1 ₂ of high strength bolts of the joint surface area 2 A shearing force acts on the shaft portion, and the high-strength bolt 2 is broken.
Therefore, in the present invention, the sheath material 5 having a material shaft length Ls shorter than the fastening length L and formed of a high strength material having a tensile strength of 1700 to 2600 MPa is inserted into the shaft portion of the high strength bolt 2. When a large stress exceeding the frictional force is applied to the joint and a shearing force is applied to the biaxial portion of the high strength bolt, the shear strength of the high strength bolt 2 is reinforced within the strength range of the sheath material 5. It strengthens the maximum proof stress as a joint.
In the present invention, the sheath material 5 having a tensile strength of 1700 to 2600 MPa is used. However, such a high-strength material can satisfy the demand to remarkably enhance the maximum proof stress from the current level within the range that can be realized at present. Furthermore, in the present invention, this is an indispensable (major premise) condition. If the tensile strength is less than 1700 MPa, the strength is the same as the strength of high-strength bolts. Moreover, since it was not commensurate with the cost of a steel plate if it exceeds 2600 MPa, it was set to 2600 MPa or less.

This sheath material 5 is basically composed of a high strength steel material, a superalloy, or a special metal. The sheath material 5 is composed of a short pipe as shown in FIG. 2 (a) or as shown in FIG. 2 (b). A sheath material 5 ₁ composed of molded bodies 5a and 5b arranged so as to face each other from both sides of the high-strength bolt 2 in such a shape that the short pipe is divided in half, or as shown in FIG. A typical example is a sheath material 5 ₂ made of a molded body in which the plate is formed into a cylindrical shape and the end faces are not joined together (easily inserted into the high-strength bolt 2 shaft using elasticity).
These sheath materials (represented by 5 here) are interposed between the bolt hole 1o and the two high-strength bolt shafts so as to resist at least the shearing force on the two high-strength bolt shafts. In this case, it is not indispensable to cover the entire circumference of the high-strength bolt biaxial portion, but in order to function stably even when the sheath material 5 moves between the bolt hole 1o and the high-strength bolt biaxial, It is more preferable to interpose so as to cover the circumference.

As conditions for this sheath material 5, in order to make a high strength characteristic function efficiently, it is preferred that the following (1) to (4) are satisfied, for example. These conditions include the conditions of the plate-shaped part to be joined (here, thick steel plate), the conditions for forming the friction surface, the high-strength bolt (including nuts and washers) conditions, the tightening axial force, the allowable strength, and the required maximum strength. It will be selected accordingly.
(1) Length Ls: slightly shorter than the tightening length L of the high strength bolt 2. This is to prevent delayed destruction of the sheath material 5 by preventing stress from acting on the sheath material 5 at all times. However, at least a length that can sufficiently cover the shearing force acting area for the high-strength bolt 2 is required. (Here, the length of the sheath 5 is if degree 0.6-0.9 thick steel plate 1 ₁ having a thickness of + steel plate 1 ₂ thick in the state of introducing the axial clamping force, normally Tightening axial force does not act, and it can function satisfactorily while eliminating the fear of delayed fracture.)
(2) Inner diameter d: High-strength bolt biaxial diameter + over 0 to about 1 mm. In order to increase the contribution ratio of the high-strength characteristics of the sheath material 5, the gap between the high-strength bolt 2 shaft and the inner surface of the sheath material 5 is preferably as small as possible, but the sheath material 5 can be smoothly inserted into the high-strength bolt 2 shaft. It is necessary to form a gap.
(3) Thickness t: about 1 to 5 mm. The reason why 1 mm or more is necessary is a thickness necessary for maintaining sufficient shape rigidity and ensuring stable high strength characteristics. When the thickness exceeds 5 mm, the diameter of the bolt hole 1o becomes too large, too close to the head diameter of the high strength bolt 2 or the outer diameter of the nut 3, as shown in FIG. In addition to the standard washer 4 in order to transmit the tightening axial force, the plate washer 4w is used and other problems such as processing to form the joint, increased work load, and unstable transmission of the tightening axial force. Since it occurs, the range is preferably up to about 5 mm.
(4) Gap between sheath material 5 and bolt hole 1o: More than 0 to about 1 mm. In order to increase the contribution ratio of the high strength characteristics of the sheath material, the gap between the high strength bolt 2 shaft, the sheath material 5 and the bolt hole 1o is preferably as small as possible, but the sheath material 5 is disposed between the high strength bolt 2 shaft and the bolt hole 1o. In order to arrange (insert) smoothly, a gap is necessary. However, if the gap is too large, it will cause looseness, so it should be about 1 mm or less. The sheath material 5 can be easily mass-produced by a general pipe manufacturing method or cold forming.

The high-strength bolt 2 used in the present invention is a high-strength bolt having a tensile strength of 700 to 1600 MPa.・ In addition to the flat washer set, as shown in FIG. 4A, the shaft 2a has a male screw 2s for screwing the nut 3 and a tightening torque introducing mechanism (pin tail) 6 at the tip. , to cooperate with the nut 3 and pintail 6, known torque shear-type high-strength bolts 2 ₁ capable tightened while managing tightening torque or, as shown in FIG. 4 _(b),, screwing the nut 3 in the axial portion 7a It has a male screw 7s, a tightening torque introduction mechanism (pin tail) 6 is provided on the head, and the pin tail 6 and the square washer 8 inserted in the head seat surface can cooperate to tighten while controlling the tightening torque. Known head tightening The torcia type high strength bolt 7 is used. However, other types of high strength bolts are not excluded.
In addition, washers other than the square washer 5 of the head-clamped torcia-type high-strength bolt 4 are used as necessary.
The characteristics of the nut, hardness _H R B95 a minimum, up to _H R C35, for the characteristics of the washer, hardness, may be those of the _H R _C35~45.
In the case of using an accessory plate or a joint metal, it is preferable that the characteristic is equal to or higher than that of the member to be joined.
In addition, it is not indispensable that the high strength bolts 2 and 7 used in the present invention, nuts 3, washers 4, accessory plates and joint hardware are all of the same characteristics, depending on the joint part and also in the same joint part, It can be used properly according to the load load, and it is also considered to use a conventional characteristic in combination.

As the high strength bolt friction joint applying the present invention, in addition to the above embodiment, for example, (1) as shown in FIG. 5, the steel plate 1 _1, 1 ₂ as bonding target, small joints Two face friction bonding with one high-strength bolt 2 through a splicing plate 8 that is in contact with the upper and lower surfaces across the butted thick steel plates 1 ₁ , 1 ₂ so as to generate a gap a (one splice plate) A high-strength bolt friction joint that allows one-surface friction.
(2) As shown in FIG. 6, as the bonding target column member by square tube 9 _1, 9 _2, butt wood axis direction, the four sides, respectively, the添板10 in contact with the inner side and the outer side A high-strength bolt friction joint that performs two-surface friction with a high-strength bolt 2 (one plate friction is possible with a single plate).
(3) As shown in FIG. 7, the upper and lower surfaces of the H-shaped steel beams 11 ₁ and 11 ₂ are bonded to the upper and lower flanges 11 a and 11 b that are abutted so as to generate a gap a in the axial direction. A high-strength bolt friction joint that performs two-surface friction (single-surface friction is possible) with the high-strength bolt 2 through the accessory plates 12 ₁ and 12 ₂ that are in contact with each other.
Etc. are typical ones.

As shown in FIG. 1, high-strength bolts 2 of 1400 MPa class (M20) are obtained by superposing thick steel plates 1 ₁ and 1 ₂ having a thickness of 25 mm and a width of 100 mm in a 590 MPa class (yield point 440 MPa class) as a material to be joined. ) In the material axis direction (one row in the width direction) and one surface friction welding was performed, the applied load was gradually increased from 0 kN until the bolt broke, and an experiment was conducted to confirm the effect of the sheath material. An experimental result is shown in FIG. 8 with the case of the conventional friction joining part which does not interpose a sheath material. In this experiment, the joint performance up to the break of the high-strength bolt was evaluated in terms of applied load and joint elongation change.
In the case of the conventional friction joint part, conditions other than a sheath material are the same as an experimental example.
[Experimental conditions]
High strength bolt (SHTB)
Shaft diameter: 20mm
Tensile strength: 1400 MPa
Tightening length: 50mm
Bolt hole Hole diameter: 24mm
Pitch: 60mm
Sheath material (2000MPa steel)
Inner diameter: 20.5mm
Thickness: 1.0mm
Tensile strength: 2000 MPa
Nut: Hardness H _R C 35
Washer: Hardness H _R C 40
Tightening axial force: (1400 MPa × effective area of threaded portion × 0.74) = 290 kN

[Experimental example]
(1). As shown in FIG. 8, in the friction joint portion of the present invention with the sheath material interposed, “slip” occurs at 250 kN corresponding to the proof stress level of the primary design. The bearing and shear conditions were reached, the load increased, showed a maximum value at 660 kN, and then showed a slight decrease in load.
(2). From (1), the maximum proof stress as a joint part of the friction joint part of this invention can be evaluated to be about 660 MPa. In addition, the trace of the occurrence of delayed fracture was not recognized in the high strength bolt after the fracture. Although the sheath material was sheared, no delayed fracture was observed.

[Conventional example]
(3) In contrast, as shown in FIG. 8, in the friction bonded portion where no sheath material is interposed, “slip” occurs at 250 kN corresponding to the proof stress level of the primary design. Became a bearing / shear state, the load increased, showed a maximum value at 550 kN, and then showed a slight load drop, after which the bolt was shear broken.
(4). From (3), it can be evaluated that the maximum proof stress as the joint of this friction joint is about 550 MPa. In addition, the trace of the occurrence of delayed fracture was not recognized in the high strength bolt after the fracture.

  From the above results, the friction joint of the present invention interposing a high-strength sheath material ensures the allowable strength for the primary design equivalent to the conventional friction joint without interposing the sheath material, and as a joint It was confirmed that the maximum proof stress of can be increased to about 1.2 times. As a result, it is clear that the number of bolts can be significantly reduced at the joint where the number of bolts is determined by the maximum proof stress.

  The present invention is not limited to the contents of the above-described embodiment, and depending on the joint characteristics required for the joint part to be applied, the type of high-strength bolt to be used, the tensile strength, the number of bolts, and the tightening axial force The material of the sheath material, the tensile strength, the shape and the like are changed within a range satisfying the claims.

Side sectional explanatory drawing which shows the example of embodiment of the high strength bolt friction junction part of this invention. (A), (b), (c) is three-dimensional explanatory drawing which shows the shape (structure) example of the sheath material used by this invention. Side sectional explanatory drawing which shows the other embodiment example of the high strength bolt friction junction part of this invention. (A), (b) is side explanatory drawing which shows the example of the high strength volt | bolt to which this invention is applied. Side cross-section explanatory drawing which shows the example of the friction junction part of the thick steel plate object to which this invention is applied. Side cross-section explanatory drawing which shows the example of the high strength bolt friction junction part of the square steel pipe object which applies this invention. Side cross-section explanatory drawing which shows the example of the high strength bolt friction junction part of the H-section steel object which applies this invention. Explanatory drawing which shows the example of an evaluation experiment result of the high strength bolt friction junction part of this invention. Side sectional explanatory drawing which shows the general example of the friction joining part which applies the high strength bolt friction joining part of this invention. Explanatory drawing of the thread part effective cross-sectional area used for the fastening axial force setting according to the tensile strength of a high strength bolt.

Explanation of symbols

1 ₁ , 1 ₂ Thick steel plate 1o Bolt hole 2 High strength bolt 2 ₁ High strength bolt (Torsia type)
2a Shaft 2s Male thread 3 Nut 4 Washer 5, 5 ₁ , 5 ₂ Sheath material 6 Pin tail 7 High strength bolt (head tightening torcia type)
7a shaft portion 7s male screw octagonal washer 9 _{1, 9 2} square tube (pillar)
10 Substrate 11 ₁ , 11 ₂ H-shaped steel beam 11a Upper flange 11b Lower flange 12 ₁ , 12 ₂ Substrate

Claims (5)

A high-strength bolt friction joint of a steel member for constructing a construction steel structure using a high-strength bolt having a tensile strength of 700 to 1600 MPa ,
A sheath material having a material length shorter than the tightening length for the member to be joined and a tensile strength of 1700 to 2600 MPa between the shaft portion of the high strength bolt inserted into the bolt hole of the member to be joined and the bolt hole , Insert it so as not to apply stress at all times, thereby avoiding delayed destruction of the sheath material,
When a stress exceeding the allowable strength acts on the joint and a shear force acts on the shaft portion of the high strength bolt, the shear strength of the high strength bolt is reinforced by the high strength characteristics of the sheath material, thereby A high-strength bolt friction joint for steel members characterized by strengthening the maximum shear strength of steel. Claims between washer and the bonded member interposed in high strength bolts, is interposed a plate washer having the above washer thickness, the axial clamping force, characterized in that the friction joint is transmitted to the workpieces A high-strength bolt friction joint of the steel member according to 1 . The sheath material is a sheath material composed of a short tube, a sheath material composed of a molded body arranged so as to be opposed to both sides of the high-strength bolt in a shape that halves the short tube, and an end surface formed by molding the plate into a cylindrical shape The high-strength bolt friction joint portion of the steel member according to claim 1 or 2, wherein the sheath member is a sheath material made of a molded body that does not join the steel member. The length of the sheath material is 0.6 to 0.9 times the thickness of the member to be joined in a state where the tightening axial force is introduced,
The thickness of the said sheath material is 1-5 mm, The high strength bolt friction junction part of the steel frame member of any one of Claims 1-3 characterized by the above-mentioned. An architectural steel structure having one or more high-strength bolt friction joints of the steel member according to any one of claims 1 to 4 .

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