Wooden column-beam joint structure and joint member

Abstract

To solve the problem that wooden column-beam joint structure is unable to absorb energy and often not strong enough to ensure habitability after shaking from earthquakes and other events.SOLUTION: There is provided joint structure that joins upper and lower wooden column members to right and left wooden beam members perpendicular to the wooden column members. The upper and lower frame members are fixed to a pair of opposing side frame members. For a frame member having an axial force support member fixed between the upper frame member and the lower frame member and a yielding member fixed to the pair of side frame members, the upper and lower wooden column members are joined to the upper frame member and the lower frame member, respectively. The joint structure in which the right and left wooden beam members are joined to the pair of opposing side frame members receives vibrations only at the yielding member and absorbs energy by deforming, so the building can remain in a habitable state even after experiencing vibrations.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a joint structure and a joint member for a column-beam joint of a wooden structure.

Background Art

[0002] In the column-beam joint of a wooden frame structure, a slip phenomenon occurs and energy absorption is extremely small. Compared with a steel frame structure or a reinforced concrete structure with the same rigidity and load-bearing capacity, the response displacement during an earthquake becomes large, which is cited as a problem. Furthermore, even for an earthquake load or wind load that does not reach the ultimate state, in a history with slip, plasticization occurs, resulting in a slip phenomenon and a significant reduction in rigidity, thus impairing the habitability.

[0003] In a wooden frame structure with a through column, the main causes of slip in axial force-resistant moment joints such as GIR (Glued in Rod), LSB (Lagscrewbolt), and tension bolts (collectively referred to as joining tools) are: (1) the joining method of bolts that resist only on the tensile side; (2) plastic deformation of wood such as indentation yield on the column side surface.

[0004] In addition, the problems of a frame structure using wooden members are as follows: the following two points (a) and (b). (a) The shear strength and shear rigidity of wood are significantly smaller than those of bending, compression, and tension. Therefore, when the joining efficiency is high, the column-beam joint (panel zone) undergoes shear failure and the load-bearing capacity reaches its peak. (b) In order to ensure toughness performance, a method is generally used in which a part of the cross-section of the joining tool on the tensile side of the moment joint of the column or beam is reduced to cause tensile yield and ensure the elongation amount. The presence of this part significantly reduces the rotational rigidity of the joint.

[0005] In the steel frame construction, the technology of shear yielding the panel zone (web), which is the joint part of the H-shaped steel column and beam, by using low yield point steel is a vibration control technology. However, due to the influence of the compressive axial force, it is not applied to the main column-beam joint parts of the ramen structure where the compressive axial force acts.

[0006] Patent Document 1 discloses an invention that enables the shear force of the beam member to be transmitted to the column member through the grid-shaped steel plate and the shear force of the column member to be transmitted to the beam member through the grid-shaped steel plate by joining wooden column members and wooden beam members to the upper, lower, left, and right steel plate parts of the grid-shaped steel plate formed by combining steel plates in a grid shape.

[0007] Further, Patent Document 2 discloses a joint structure between a wooden member and a steel member in which a wooden beam (wooden member) is joined through a steel joint fixed to a steel pipe column (steel member) as a method of enhancing energy absorption by using low yield point steel when using wooden members. The steel joint has a first part whose base end is fixed to the steel pipe column and a second part joined to the wooden beam over a predetermined length from the tip end, and at least the yield strength of the first part is formed lower than that of the steel pipe column and the wooden beam.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Patent Document 2

Non-Patent Documents

[0009]

Non-Patent Document 1

Non-Patent Document 2

Summary of the Invention

[0010] Patent Document 1 provides a structure that is less likely to cause "sinking" which causes slippage between wooden column members and wooden beam members, but it does not provide a structure that absorbs the energy of vibrations caused by earthquakes.

[0011] Although Patent Document 2 provides an energy absorbing structure using yielding members, it is a method for joining steel column members and wooden beam members, and is not for joining wooden column members and wooden beam members.

[0012] Therefore, the present invention provides a one-way rigid frame structure that solves all of the above causes (1) and (2) and problems (a) and (b) and provides stable energy absorption characteristics.

[0013] Furthermore, with conventional joint methods, the axial force affects the bending moment in the columns, making the design complicated. Furthermore, in through-column rigid frame structures, the shear strength of wood is low, so prior art methods have been developed to replace the panel zone with steel frames or reinforced concrete for large, high-rise buildings, but these methods are expensive and not commonly used for low-cost rigid frame structures up to about four or five stories. [Means for solving the problem]

[0014] The joint structure of the present invention provides a joint structure in which the column-beam joint of a wooden structure is constructed using panel zone hardware, which causes the panel zone hardware to shear yield before the moment joints of the wooden column members and wooden beam members, thereby forming a collapse mechanism.

[0015] More specifically, the joining structure for joining wooden column and beam members according to the present invention is as follows: A joining structure for joining upper and lower wooden column members and left and right wooden beam members perpendicular to the wooden column members, The upper frame member and the lower frame member are fixed to a pair of opposing side frame members, an axial force support member fixed between the upper frame member and the lower frame member; With respect to the frame member having the yielding member fixed to the pair of side frame members wherein the upper and lower wooden column members are joined to the upper side frame member and the lower side frame member, respectively, and the left and right wooden beam members are joined to the pair of opposing side frame members.

Advantages of the Invention

[0016] The joining structure according to the present invention uses a yielding member in the panel zone and has a collapse structure against shaking, so that a joining structure with high energy absorption can be provided. Therefore, it is difficult for the building itself to collapse, and the vibration energy is absorbed by the yielding member being crushed, so that the building after the vibration experience can also remain in a livable state.

[0017] In addition, in the prior art of the method of replacing the panel zone with a steel frame, the panel zone hardware is prefabricated in a factory. On the other hand, the present invention also includes a method in which a part of the panel zone hardware itself is attached to a wooden member in advance in a factory, and these, a yielding member, an axial force support member, etc. are assembled with high-tension bolts on-site. Therefore, it is possible to absorb construction errors, and also has the effect that the yielding member can be replaced even if it is damaged by a large earthquake or the like depending on the fit.

[0018] In addition, the amount of steel frame used is small, and by reducing the horizontal resistance force by the members that vertically support and the members that horizontally resist, the members that vertically support and the members that horizontally resist are independent of each other, the design is clear and easy, and construction can be carried out at low cost.

Brief Description of the Drawings

[0019]

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[0020] The joining structure and joining member according to the present invention will be described below with reference to drawings and examples. Note that the following description exemplifies one embodiment of the present invention and one example, and the present invention is not limited to the following description. The following description can be modified within the scope of the present invention.

[0021] Furthermore, embodiments and examples obtained by appropriately combining the technical means disclosed in different embodiments and examples are also included in the technical scope of the present invention. Furthermore, all documents described in this specification are incorporated herein by reference. In this specification, when a numerical range is described as "A to B," this means "greater than or equal to A and less than or equal to B."

[0022] Fig. 1 shows a joining member that realizes the joining structure according to the present invention. The vertical direction of the frame member 10 is the direction in which the wooden column members are arranged, the direction in which the side frame members are arranged is the left-right direction, and it is the direction in which the wooden beam members are arranged. In addition, the direction perpendicular to the plane formed by the wooden column member and the left and right wooden beam members is called the orthogonal direction. The orthogonal direction is the direction of "front" and "rear" shown in the drawing. Note that the state of viewing from the front direction to the rear direction is defined as "front view".

[0023] The joining member 1 includes a frame member 10, an axial force support member 12, and a yielding member 14. The frame member 10 is a metal fitting used in a panel zone that is a joint portion between a wooden column member and a wooden beam member. The frame member 10 is composed of an upper frame member 10a, a lower frame member 10b, and a pair of left and right side frame members (left side frame member 10c, right side frame member 10d) facing each other. These members constituting the frame member 10 are collectively called frame members. The widths of the respective frame members are the same.

[0024] Both ends of the upper frame member 10a and the lower frame member 10b are fixed to the pair of left and right side frame members 10c and 10d, and are configured in a cylindrical shape as a whole. The fixing between the respective frame members is performed by a method such as bolting or welding.

[0025] In Fig. 1, a state is shown in which fixing brackets 30 and 32 for the upper frame member 10a and joining brackets 34 and 36 for the lower frame member 10b are provided on the left and right side frame members 10c and 10d. The upper frame member 10a and the lower frame member 10b are fixed to the left and right side frame members 10c and 10d using through holes provided in these brackets. Further, fixing brackets 40 and 42 for fixing the yielding member 14 may be provided on the left and right side frame members 10c and 10d.

[0026] The axial force support member 12 is a support member disposed between the upper frame member 10a and the lower frame member 10b. It is disposed at a position substantially equidistant from the left and right side frame members 10c and 10d. The axial force support member 12 is formed by combining a pair of L-shaped equal-angle angles 12a and 12b. Note that the two L-shaped equal-angle angles may be replaced with two square steel pipes.

[0027] Figure 2 shows an enlarged view of the axial force support member 12. One side of the equal-angle 12a is referred to as the angle plate portion 12aA, and the other side is referred to as the angle plate portion 12aB. Similarly, for the equal-angle 12b, one side is referred to as the angle plate portion 12bA, and the other side is referred to as the angle plate portion 12bB. The upper and lower ends of each angle plate portion A (12aA, 12bA) are cut off.

[0028] The pair of equal-angles 12a and 12b are arranged such that the angle plate portions B (12aB, 12bB) face each other in the front-rear direction, and the angle plate portions A (12aA, 12bA) of each face each other in the left-right direction.

[0029] More specifically, one equal-angle 12a has the angle plate portion 12aB facing forward and the angle plate portion 12aA facing the left frame member 10c. The other equal-angle 12b has the angle plate portion 12bB facing rearward and the angle plate portion 12bA facing the right frame member 10d. At this time, they are arranged such that the plate thickness center lines C of the angle plate portion 12aB and the angle plate portion 12bB are aligned.

[0030] Figure 3 shows a front view when FIG. 1 is assembled, and FIG. 4 shows an A-A cross-section of FIG. 3. However, the yielding member 14 is not included. As also shown in FIG. 2, the equal-angles 12a and 12b are arranged at a distance d apart in the front-rear direction. This distance d is at least wider than the plate thickness t (see FIG. 1) of the yielding member 14.

[0031] The equal - angle members 12a and 12b may be directly fixed to the upper frame member 10a and the lower frame member 10b by welding or the like. However, the fixing brackets 44 and 46 may be fixed vertically by welding or the like, and then the fixing brackets 44 and 46 may be bolt - fastened to the upper frame member 10a and the lower frame member 10b. Of course, the support member 12 is not excluded from being directly welded to the upper frame member 10a and the lower frame member 10b. In FIG. 1, the equal - angle members 12a and 12b are collectively connected by the fixing brackets 44 and 46, showing an integrated shaft support member (they may also be separate instead of integrated).

[0032] Also, in FIG. 3, the angle - plate portion A of the support member 12 has its upper and lower ends cut off, and when viewed from the front, it shows a state of being a pin joint Pin between the upper frame member 10a and the lower frame member 10b. Note that FIG. 3 shows the case where the fixing brackets 44 and 46 are absent. Such a support member 12 may be described as a pair of parts with different cross - sectional shapes other than the upper and lower ends that can support the vertical load.

[0033] Referring to FIG. 1 again. The yielding member 14 has fixing flange portions 14a and 14b on the left and right, and the central portion 14c is a plate portion that serves as the yield point and is a plate material in the shape of "H" when viewed from the front. For the yielding member, it is desirable to use a low - yield - point steel that has lower strength and higher ductility compared to conventional mild steel. However, since it is not easy to obtain in small lots, ordinary steel materials with a clear upper limit of strength may also be used. For the yielding member 14 of this shape, the central portion 14c (the portion connecting both ends) is preferably installed horizontally.

[0034] The left and right fixing flanges 14a and 14b are fixed to the left and right side frame members 10c and 10d. This fixing may be by welding, or may be bolt - fastened with HTB (high - tension bolts) to the fixing brackets 40 and 42 provided on the left and right side frame members 10c and 10d shown in FIG. 1. Bolt - fastening is preferable because it enables the replacement of the yielding member 14 after experiencing vibrations such as earthquakes.

[0035] Figure 5 shows the combined state of the frame member 10, axial force support member 12, and yielding member 14 shown in Figure 1. The frame member is fixed by bolts with fixing brackets 30, 32, 34, and 36. The axial force support member 12 is also fixed to the upper frame member 10a and the lower frame member 10b via fixing flanges 44 and 46. The yielding member 14 has fixing flange portions 14a and 14b bolted and fixed to the fixing brackets 40 and 42 of the left and right side frame members 10c and 10d.

[0036] Note that the yielding member 14 is arranged through the gap formed between the equal - angle members 12a and 12b of the axial force support member 12. Returning to Figure 4, this point will be explained. The front surface of the fixing bracket 40 is flush with the front surface of the angle plate portion 12bA of the equal - angle member 12a, and the rear surface of the fixing bracket 42 is flush with the rear surface of the angle plate portion 12aA of the equal - angle member 12b. As a result, the distance between the front surface of the angle plate portion 12bA of the equal - angle member 12a and the rear surface of the angle plate portion 12aA of the equal - angle member 12b is also separated by d, similar to the interval between the equal - angle members 12a and 12b.

[0037] Figure 5 shows, in dotted lines, the upper column member WP1 joined to the upper frame member 10a and the lower column member WP2 connected to the lower frame member 10b. Also shown in dotted lines are the left beam member WL1 joined to the left frame member 10c and the right beam member WL2 joined to the right frame member 10d.

[0038] The upper column member WP1, the lower column member WP2, the left beam member WL1, and the right beam member WL2 are each provided with through - holes and fixed to the fixing steel plates 50, 52, 54, and 56 joined to the upper frame member 10a, the lower frame member 10b, the left frame member 10c, and the right frame member 10d with screw bolts or the like. However, in the top floor or outer columns, there may be cases where columns or beams do not attach to the fixing steel plates 50 - 54. Also, the fixing steel plates may be other connectors (such as bonded reinforcing bars (GIR), large - size screw bolts (LSB), etc.).

[0039] In addition, the angle plate portions 12aB and 12bB of the equal-leg angles 12a and 12b of the axial force support member 12 facing in the front-rear direction are also used as gusset plates when connecting to the beam member in the front-rear direction.

[0040] Fig. 6 shows a state where the frame member and the axial force support member 12 are fixed to each other and the situation when replacing the yielding member 14. When the yielding member 14 is bolted to the fixing brackets 40 and 42 of the left and right side frame members 10c and 10d, the yielding member 14 can be taken in and out by removing the bolts.

[0041] Fig. 7 shows a view taken along the B-B cross-section of Fig. 6. The yielding member 14 fixed to the left and right side frame members 10c and 10d can be tilted within the frame member by removing the bolts, and can be removed by passing through the end of the left side frame member 10d and pulling it forward. The yielding member that has been vibrated and deformed due to an earthquake or the like can be taken out in this way, and a new yielding member can be inserted into the frame member and fixed.

[0042] In the joining structure according to the present invention, the long-term axial force as a structure is supported by the axial force support member 12 and the frame member 10. Since the yielding member 14 is attached in the horizontal direction, there is no influence of the long-term axial force at all. Therefore, in the design, the vertical load and the horizontal load can be designed independently. Also, over a long period of time, no force is applied to the yielding member 14 and it does not deform. That is, over a long period of time, it can serve as an energy absorber.

[0043] Also, when there is lateral shaking due to an earthquake, the frame member 10 and the main body of the axial force support member 12 do not deform, and only the ends function as pin joints and deform. Therefore, since the yielding member 14 undergoes bending yield or shear yield, the energy of the shaking is absorbed here, and the strength of the joint after the shaking can be maintained. In this case, with respect to the lateral shaking of the frame member 10, the angle plate portions A (12aA, 12bA) of the equal - angle bars 12a and 12b of the axial force support member 12 facing the lateral direction have their upper and lower ends shaved off, and even when the frame member 10 tilts laterally, they do not contact the upper - side frame member 10a and the lower - side frame member 10b. Therefore, the lateral shaking is resisted only by the yielding member 14.

[0044] Figures 8 and 9 show a modified example of the connection structure according to the present invention. Figure 8 is an assembly drawing, and Figure 9 shows the assembled state. Note that the left - hand fixing steel plate (reference numeral 54 in Figure 1) is omitted. On the left and right sides of the upper - side frame member 10a, there are provided 10ag which are flanges for supplementing the welding lengths of 50, 52 and 10a, 10b, and each is a single part. Here, a single part means an object made from one base material or a part integrally formed by welding or the like. 30, 10d, 72, 40, 34, 56 or 32, 10c, 72, 42, 36 are welded single parts. 50, 52, 56 are respectively pre - attached to the wooden members of the column and the beam and carried to the site, and then 30, 32 and 10a, or 34, 36 and 10b, the yielding member 14 and 4 and 420, and the axial force support member 12 and the upper - and lower - side frame members 10a, 10b are bolt - joined differently. By providing a gap 72 and a notch 70 between the connection brackets 30, 32, 34, 36, breakage at the welded parts of 30, 34 and 10d or 32, 36 and 10c is prevented.

[0045] When lateral shear forces are applied to the joint member 1 in a front view, it deforms into a parallelogram, and further, the yielding member 14 yields to absorb the energy of the shaking. In the design, the shear performance of the joint member 1 is adjusted according to the shape of the yielding member 14.

[0046] Figures 10 and 11 show further modified examples of the connection structure. Figure 10 is an assembly drawing, and Figure 11 shows the assembled state. In this modified example, the connection between the upper frame member 10a and the left and right side frame members 10c and 10d is made by a portion that continuously extends downward from the flanges 10ag provided on both sides of the upper frame member 10a for ensuring the welding length.

[0047] In the case of the connection between the lower frame member 10b and the left and right frame members 10c and 10d, it is also made by the connection brackets 34 and 36 that extend upward from the flanges 10bg provided on both sides of the lower frame member 10b for ensuring the welding length.

[0048] Also, in the relationship between the right side frame member 10d and the connection bracket 30, a bolt joint surface 40a parallel to the right side frame member 10d is provided on the fixing gasket 40 for fixing the yielding member 14, and the connection bracket 30 is fixed by sandwiching it between this joint surface 40a and the right side frame member 10d and then bolting. The connection between the left side frame member 10c and the upper frame member 10a, and the connection between the lower frame member 10b and the left and right side frame members 10c and 10d are the same.

[0049] Then, notches 70 are provided on the upper frame member 10a side of the connection brackets 30 and 32. The lower connection brackets 34 and 36 are also provided with notches 70 on the lower frame member 10b side to serve as adjustment margins during the design of the frame members.

[0050] In the cases of Figures 10 and 11 as well, similar to the cases of Figures 8 and 9, the upper, lower, left, and right side frame members are deformed into a parallelogram shape at the notch 70 portion, and the yielding member 14 yields to absorb the energy of the sway. Note that in the cases of Figures 10 and 11, the notch 70 may not be necessary.

Example

[0051] Hereinafter, the joint member according to the present invention will be described as a PZ metal fitting (panel zone metal fitting). <Design of PZ Metal Fitting and Specification of Test Specimen> The shear force Qp acting on the PZ metal fitting with respect to the external force from the column and the beam is given by Equation (1) as shown in Figure 12.

[0052]

number

[0053] where M bL , M bR are the bending moments acting on the PZ hardware from the left and right beam ends, respectively, and Q cU , Q cD are the shear forces acting on the PZ hardware from the upper and lower column ends, respectively. The full plastic strength of the PZ hardware alone at shear yield and shear ultimate is given by equation (2) using the energy method based on the full plastic moment Mp of the plastic hinges that occur in each part, as shown in Figure 13.

[0054]

number

[0055] where: Q p : Shear force acting on PZ hardware M L : Total plastic moment of plastic hinge at corner of frame M S : Total plastic moment of the plastic hinge at the end of the axial support member M H : Full plastic moment of the plastic hinge occurring at the yield point γ, δ, θ, L, l y :See Figure 13 The total plastic moment M at the yield and ultimate state of each yield hinge py and M pu is given by equation (3).

[0056]

number

[0057] where Z p : Total plastic section modulus of the plastic hinge part, σ y , σ max: The yield point and tensile strength of the steel material at the plastic hinge part. Hereinafter, when the yielding part is M pu is defined as the maximum bearing capacity in calculation. The yield shear bearing capacity Q y of the PZ hardware is approximately M L = M S = 0 and M H = Z·σ y since the shear rigidity by the corner part of the frame member and the axial force support member is extremely small, and can be obtained as. Here, Z is the section modulus of the yielding part.

[0058] The yielding part is SN490B, and SS400 is used for the rest. In order to minimize the bending resistance of the axial force support member, as shown in Fig. 3, the end of the equal - angle section (L - 75×75×12mm) of the axial force support member is shaped such that only one side is welded to the frame member, and the axial force is verified for its cross - section. In the design of the PZ hardware, tensile tests of the corner part of the frame member that dominates the bearing capacity of the PZ hardware, the angle of the axial force support member, and the steel plate at the yielding part, and a compression test of the axial force support member alone were carried out. The results are shown in Table 1 and the outline of the compression test of the axial force support member alone is shown in Fig. 14.

[0059]

Table 1

[0060] From the compression test results of the axial force support member alone, plastic buckling was not confirmed. The yield bearing capacity per piece is 300 kN, which exceeds the calculated value (266 kN) of the cross - sectional area of the welded part (75×12mm) × yield point (296 N / mm2). It was also confirmed that the cross - section on the diagonally notched side (the round part in Fig. 14) also resisted compression. The long - term allowable compression bearing capacity in design obtained only from the welded cross - section is 141 kN / piece. The pin - jointed parts at the corner of the frame member and the upper and lower ends of the yielding member are designed not to yield only under axial force and shear force in order to maintain the function as a pin - joint even at the maximum bearing capacity.

[0061] There are two types of PZ metalware, a total of five pieces with the shape of the yielding part as a variable. The LW series is a type that welds the yielding part and the frame material and joins it to the wooden member with LSB. In the DB series, with the frame material in common, the yielding part and the frame material are friction-joined by 3-M30 (F10T), aiming to make the yielding part into a component to cope with various design conditions, and it is a type that joins the wooden member with a steel plate inserted drift pin. A list of the target performance and specifications of each test piece is shown in Table 2, and the test piece diagrams of each test piece are shown in Figs. 15 to 18. The wooden member used was a JAS standard symmetric non-homogeneous structural Hokkaido larch laminated wood E105-F300 of 150 mm × 500 mm.

[0062]

Table 2

[0063] In the LW series, above the fit of the bolts and nuts at the joint between the LSB (Φ20, M18 male screw type (crest diameter: 20.5 mm, root diameter: 14.1 mm)) and the frame material, the frame material and the yielding part were welded. The metalware with a steel plate inserted drift pin joint and the frame material were joined with 4-M20 (F10T).

[0064] To ensure that no slip phenomenon occurs at the ultimate bearing capacity of the PZ metalware, each moment joint between the wooden member and the PZ metalware is designed to be below the yielding moment at the ultimate bearing capacity of the PZ metalware. Specifically, in the single tensile test of the LSB, the 5% lower limit value of the pull-out bearing capacity per piece is P max = 85 kN, and since there is almost no plastic region 5), when the short-term allowable tensile bearing capacity is Tlsb = 2 / 3P max = 56.65 kN, the yielding face moment My at the LSB joint at the end of the wooden member is calculated by Equation (4). When the yielding part (= yielding member) reaches the ultimate moment (Mpu), the face moment of the column is designed so that it becomes 60% and 71% of My of each LSB joint for LW1 and LW2, respectively, for the cross-section of the yielding part.

[0065]

Equation

[0066] where T LSB-i is the pulling force of the i-th LSB on the pulling side, d i is the distance from the compression edge to the center of gravity of the i-th LSB on the tension side. In the DB series, the yield strength of the DP joint was designed in advance according to Non-Patent Document 1 to achieve a bending strength (Z·Fb, where Z is the section modulus and Fb is the reference bending strength) that is 56% of the full cross-section of the wood member and 72% when cross-sectional loss is taken into account. As shown in Figures 15 to 18, the DP joints were made to a common specification. Therefore, the steel-inserted drift-pin joint, which allows for the joint strength with the wood side to be freely set, is more compatible with PZ hardware than LSBs. The friction joint between the yield point and the mounting plate in the DB series was designed so that the short-term allowable shear strength of the single-face friction was below the upper limit of the full plastic moment (Mpu) at the yield point.

[0067] As shown in "Connection Efficiency 1" in Table 2, for DB2, which has the highest strength, the full-plastic ultimate strength was set to approximately 2 / 3 of the bending strength of the wooden member, with the entire cross-section effective, when the yield point reaches its full-plastic ultimate state. When setting the shear strength of the PZ hardware, two types of strength were set for each of the LW and DB series. In this case, the cross-section and span of the yield point were considered as variables, but in order to reduce the plastic strain per shear deformation angle γ of the PZ hardware, the span ly of the yield point was set as long as possible for LW1 and LW2, and DB1 and DB2. In contrast, DB3 was designed with a shorter span ly to have approximately the same strength as DB1, with the aim of investigating the effect of the ultimate deformation angle.

[0068] For comparison, we also designed the TC series, in which the beam side was connected to the through column with a steel plate-inserted drift pin joint of the same specifications as the DB series, and the tension and compression sides were connected to the through column with 4-LSB (Φ20, M16 male thread type (thread diameter: 20.5 mm, root diameter: 14.1 mm)) joints, with the only experimental variable being the presence or absence of axial force. The LW and DB series were subjected to a compressive axial force of 350 kN, the long-term allowable compressive strength at a buckling length of 3250 mm, assuming a medium- to large-scale building. The TC series also aimed to investigate the effect of axial force on the panel zone shear failure of the through column. To clearly demonstrate the difference between the TC without axial force and the TCN with axial force, the compressive axial force for the TCN was set to 600 kN.

[0069] <Experimental method and results> The experimental setup is shown in Figure 19. As shown in Figure 20, the measurement points were the displacement of the load application point, which is the overall deformation, the rotation angle of each moment joint, and the shear deformation angle of the PZ hardware. The loading history was based on Non-Patent Document 1, and the apparent deformation angles were repeated three times at 1 / 450, 1 / 300, 1 / 200, 1 / 150, 1 / 100, 1 / 75, 1 / 50, and 1 / 30 rad. After that, if there was no sudden deterioration in strength, one repetition was made at 1 / 15 rad.

[0070] In DB2, to confirm the influence of axial force, the compressive axial force was reduced to 2kN for the second repeated positive and negative loads at 1 / 50rad, and then the axial force was returned to 350kN for the third repeated load at 1 / 50rad. In addition, in DB3, after the 1 / 30rad experiment was completed, the yielding area was removed by gas cutting, leaving only the frame material and axial force support members, and the burden of the horizontal force with and without an axial force of 350kN was investigated.

[0071] The cracking and plastic buckling conditions of typical yielding parts are shown in Figs. 21(a) and (b). In the LW series and DB1 and DB2, after the third repetition at 1 / 30 rad., cracks occurred on the tensile side of the hinge part of the yielding part, and the cracks gradually progressed and the bearing capacity decreased smoothly according to the displacement increment at 1 / 15 rad. thereafter. No brittle bearing capacity decrease was confirmed at the end of any of the specimens. In all specimens, plastic buckling was hardly visually confirmed up to 1 / 30 rad.

[0072] In the LW series, since the plate thickness of the yielding part was thinner than that of the DB series, plastic buckling was more prominent on the compression side of the hinge part at 1 / 15 rad. than in DB1 and DB2. In DB3, as shown in Equation (2), θ per γ was larger than in DB1 and DB2. Therefore, cracks occurred on the tensile side of the hinge part of the yielding part at the second repetition at 1 / 30 rad., and the bearing capacity gradually decreased. Thus, the experiment was terminated after the third repetition. No brittle bearing capacity decrease was confirmed at the end of any of the specimens.

[0073] In Fig. 26 described later, the M-θ relationship of the moment joints of all specimens shows elastic behavior. Also, as shown in Fig. 21, the wooden members, including the moment joints, were visually undamaged.

[0074] The calculated values of the above-mentioned various bearing capacities are shown in Figs. 22 and 23, respectively, for the relationship between the load P at the loading point and the apparent deformation angle R and the Qp-γ relationship of each specimen. In the LW and DB series, history characteristics with Bauschinger effect and strain hardening, such as those of a steel frame ramen structure, were obtained under large deformation cyclic loading. The increase in bearing capacity near 1 / 30 rad. at the third repetition at 1 / 3 of DB3 is presumably due to the cracks in the plastic hinge part that occurred up to the second repetition closing and the compression resistance range expanding.

[0075] A comparison of the envelope curves of all test specimens with TC and TCN showed that all test specimens in the LW and DB series significantly exceeded the performance of TC and TCN in terms of stiffness, strength, and deformation capacity. In addition, TC and TCN had almost the same shear strength, confirming that compressive axial force had no effect on shear failure in the panel zone of the through-column construction method.

[0076] A comparison of the calculated and experimental values of maximum strength in Figures 22 and 23 showed that the calculated values were almost identical to the experimental values, confirming the validity of the calculation method described in Chapter 3. In cases such as LW2 and DB2, where the experimental values determined from the strain gauges were significantly lower than the calculated values of yield strength, this was because the strain gauge attachment position was significantly shifted from the crack initiation position where the strain was maximum, as shown in Figure 21(c).

[0077] Table 3 shows a list of the short-term allowable shear strength and other properties evaluated from the relationship between the load P and apparent deformation angle R of each specimen. Although the cross section of the yield point of DB3 is smaller than that of DB1, the maximum strength was nearly the same for both, and the initial stiffness of DB3 was higher, resulting in results as designed. In design, if a frame with good performance is considered to have four strengths that are close to each other to determine the short-term design shear strength, then for this specimen, DB3, which has slightly inferior deformation capacity, would be the best specification. As there is a great degree of freedom in the shape of the yield point with PZ metal fittings, finding the optimal shape will be a future challenge.

[0078] [Table 3]

[0079] Figure 24 shows the ratio of the shear deformation angle γ of the PZ metal fittings and the deformation angle of the moment joint to the apparent deformation angle R of each test specimen. For DB1, the test was conducted the day after the black scale was removed by sanding the friction surface, so there was very little red rust, which resulted in a small friction coefficient and a slipping sound at the friction joint from the beginning, and the rate of deformation of the PZ metal fittings for DB1 was greater at the early stage compared to DB2 and DB3. However, there was sufficient red rust in DB2 and DB3, so no slipping sound was heard at the friction joint.

[0080] In the initial stage of deformation, except for DB1, the deformation ratio of the PZ hardware is as small as about 10%. During large deformation, the ratio of the shear deformation angle γ of the PZ hardware to the total deformation is about 80%, and it is confirmed that the bending deformation of the moment joint and the wooden member is almost elastic and extremely small. A list of heq at the main deformation angles is shown in Table 4. It was confirmed that the energy absorption during large deformation is extremely large for all specimens compared with TC·TCN.

[0081]

Table 4

[0082] In the comparison of the history curves according to the presence or absence of axial force during the repeated loading of 1 / 50 rad. of DB2 shown in Fig. 25(a), by removing the axial force, although it seems to be caused by the drift pin joint on the column side, it slightly appears in the apparent deformation angle R at the part marked with ○, and the shear force Q of the PZ hardware p - In the γ relationship, γ becomes smaller by the amount of rattling. P or Q p The influence of the presence or absence of axial force on P is the difference ΔQ p = 13.8 kN between the 2nd and 3rd cycles of 1 / 50 rad. in Fig. 25(a), and by applying force only to the frame member and the axial force support member after the DB3 experiment shown in Fig. 25(b), it is almost equal to the difference in bearing capacity ΔQp = 15.6 kN between the case with and without axial force in the bearing capacity constant region where it can be judged that the full plastic moment has been reached, and these values are the difference in the full plastic moment M p due to the presence or absence of axial force according to the calculation model of the plastic hinge part of the frame member and the axial force support member in Fig. 25(c) p The corresponding shear force ΔQ p = 16.9 kN, which is almost the same. Therefore, it can be judged that the axial force has no influence on the shear performance of the yielding part.

[0083] <Estimation method for the initial shear rigidity of PZ hardware> To estimate the initial shear rigidity in the design of PZ hardware, a wire model as shown in Fig. 13 was created using SNAP Ver. 8. In the modeling of the PZ hardware part shown in Fig. 26(a), the bending rigidity of the base plate of the frame member is increased by moment connection with the wooden member and is large compared with the bending rigidities of the yielding members and hinges, so it was regarded as a rigid member. Regarding the yielding members, since the endurance load is slight, they were modeled with the bending rigidity of the cross section of the welded part.

[0084] In the modeling of the partial structure in Fig. 26(b), the moment connection parts at the column and beam ends were modeled with elastic rotational springs. The rotational rigidity of the elastic rotational springs was determined for each of the LW series and DB series in Fig. 26(c) by using the average value of the measured values of M-θ at the columns and beam ends of all the test specimens up to the maximum endurance load, since the envelope curves showed elastic behavior. Regarding the DB series, the deviation between the calculated value and the experimental value of the rotational rigidity according to Non-Patent Document 1 was about 20%.

[0085] The shear deformation angle γ was calculated from the amount of expansion and contraction between the diagonal nodes Q p - The comparison between the experimental values up to 1 / 450 rad of the γ relationship and the P-R relationship and the analytical values of the initial rigidity is shown in Fig. 27. Q p - In the γ relationship, the analytical values are higher than the experimental values. However, as shown in Fig. 24, the shear deformation component of the PZ hardware is small and its influence is negligible. Therefore, in the P-R relationship, the analytical values of the initial rigidity almost capture the experimental values.

[0086] <Examination of the ultimate deformation angle> In the experiment, load reduction occurs due to cracks occurring on the tensile side of the bending in the plastic hinge part of the yielding site. Assuming that the linear cumulative damage rule using the fatigue curve of the steel material can be applied because there is no influence of defects such as welding and plastic buckling on low-cycle fatigue, and as shown in Fig. 28(a), considerable plastic strain is distributed near the bending yield hinge and the shape does not restrain displacement against crack generation, the relationship between the half strain Δε t / 2 - crack initiation life N c of the steel material described in Non-Patent Document 2 is shown in Equation (5).

[0087]

Number

[0088] The rotation angle θ of the plastic hinge and the edge strain ε are expressed by Equation (6), and the rotation angle θ of the plastic hinge and the shear deformation angle γ of the PZ hardware are related by Equation (2).

[0089]

Number

[0090] Here, l h is the plastic hinge length, and l y is the span length of the yielding part. Then, the plastic hinge length ratio l h / l y is considered to be expressed as a function of M / QD at the yielding part. Therefore, using Femap with NxNastran Ver. 2022.1, a model as shown in Figure 28(b) with a thickness (t = 24 mm) that does not cause plastic buckling, simulating the yielding part of each test piece, was created, and a non-linear FEM incremental analysis with M / QD as a variable was performed.

[0091] The bending stiffness of the fixed-end peripheral member was set to 10 times the Young's modulus of the yielding part as shown in Figures 28(b) and (c) (2050 kN / mm 2 ) to prevent the influence of boundary conditions. For the increment in the fully plastic state where Qp is a constant value, the plastic hinge length l h is obtained from the increment Δθ of the rotation angle of the plastic hinge in the fully plastic state and the increment Δε of the maximum value of the edge strain using Equation (6), and the relationship between M / QD and l h / l y is shown in Figure 28(d). The reason for the change in the trend around M / QD = 0.8 is that shear yielding is dominant when M / QD < 0.8 as shown in Figure 28(b).

[0092] Therefore, a regression equation as shown in Equation (7) was obtained for the range of 1.4 ≥ M / QD ≥ 0.8. In the same way, l hHowever, the experimental value was smaller than that obtained by FEM due to the influence of the strain gauge measurement length (5 mm) and the misalignment between the strain gauge attachment position and the crack occurrence position as shown in Figure 21(c). h / l y As shown in Figure 28(a), l h corresponds roughly to the distribution width of the equivalent plastic strain.

[0093]

number

[0094] Here, s=M / QD, 0.8≦s≦1.4. Then, using equations (2) and (6), Q p -γ relationship is Q p The -ε relationship is converted and crack initiation prediction methods are examined using the two methods described below.

[0095] <6.1 Prediction of crack initiation using linear cumulative damage law> For low cycle fatigue, the plastic tensile strain Δε shown in Figure 29 pi (i is the number of applied load amplitudes) is the main factor, and the evaluation formula for the fatigue curve also mainly uses a variable representing the plastic tensile strain. As an example, Equation (5) expresses the plastic tensile strain for each cycle as Δε t Equation (5) is an equation that covers a wide range of fatigue conditions from high cycle fatigue to low cycle fatigue. Therefore, the strain amplitude Δε ti The crack initiation life N corresponding to ci was calculated using the pincer attack method using equation (5), and the loading cycle at which a crack occurred was determined using equation (8), which is the linear cumulative damage law.

[0096]

number

[0097] Here, N iis the number of repetitions at loading amplitude i. A comparison of the predicted crack initiation and experimental results is shown in Table 5. As shown in Figure 30, the points of strength decline observed in the experiment are indicated by crosses on the Qp-γ curve, and the loading cycles at those times are indicated by shading in the table. ΣD i = 1, cracks occur, so the cracks observed in the experiment and ΣD i The results were consistent with the predicted values.

[0098] [Table 5]

[0099] <Study based on cumulative plastic tensile strain> From the shear deformation angle γ generated in the PZ hardware, the tensile strain ε of the plastic hinge part is calculated using equation (6), and the total strain Δε, which is the strain amplitude of the i-th cycle, is calculated as shown in Figure 19. ti Elastic strain Δε when reaching full plastic moment from ei By subtracting Δε pi is Δε ti It can be calculated by the formula (9). However, the total strain Δε ti When the amplitude of the deformation angle changes, it becomes as shown in Figure 19(b).

[0100]

number

[0101] Since the history of the deformation angle, i.e., the strain history, is specified by the test method of Non-Patent Document 1, Δε pi Assuming that the influence of the slippage is small, the cumulative plastic tensile strain ΣΔε pi Therefore, the yield strength of the yielding part is the full plastic yield moment Zpσ y For strain amplitudes above this, Q at the time of unloading just before the i-th cycle p From the -ε curve, Δε ei Calculate Δε of the i-th cycle from equation (9). piBy calculating and accumulating the plastic tensile strain until crack initiation, the cumulative plastic tensile strain σΔε is obtained. pi It is calculated and shown as a solid black line in Fig. 31. The ● and ■ connected by the solid line in the figure represent the cumulative plastic tensile strain ΣΔε at the end of the cycles before and after crack initiation. pi It is shown in such a way that it can be seen at which point in the cycle crack initiation occurs.

[0102] As the yield strength increases due to strain hardening, Δε ei increases, so Δε ei / Δε ti is not a constant value. Therefore, in the design, the cumulative plastic tensile strain ΣΔε pi cannot be obtained by Equation (9). Thus, for each specimen, the ratio β of ΣΔε p σ y reached at the yield site Z to the strain amplitude up to the cycle including the load reduction point is obtained by Equation (10) and shown in Table 6. pi and ΣΔε ti is shown in Table 6.

[0103]

Number

[0104]

Table 6

[0105] Using their average values, the result of estimating ΣΔε ti from ΣΔε pi at the end of the cycles before and after crack initiation is also shown as a dashed line in Fig. 31. The ΣΔε pi at crack initiation for each specimen is approximately located between the values of ΣΔε ti estimated from ΣΔε pi at the end of the cycles before and after crack initiation. It can be judged that the method of estimating ΣΔε ti from ΣΔε pi has sufficient accuracy.

[0106] In this test specimen, even though it is SN490B, as shown in Fig. 31 and Table 1, since steel plates from three different manufacturing lots, namely LW1 and LW2, DB1 and DB2, and DB3, are used, the variation in the steel plates must be considered. Therefore, in the design, the limit value for crack occurrence determination is the 50% limit value at a 75% confidence level of ΣΔε pi at the time of crack occurrence for all test specimens. The reason is that, as shown in Fig. 31, even if it is below the 50% lower limit value, brittle fracture does not occur, and although the yield strength decreases, it can still absorb the cyclic energy of one more cycle. The ΣΔε pi at the time of crack occurrence for each test specimen and their 50% lower limit values are shown in Table 7. Therefore, the limit value for crack prediction is given by Equation (11).

[0107]

Table 7

[0108]

Equation

[0109] In the design, Δε ti can be obtained by performing incremental analysis using the analytical model of the partial structure shown in Fig. 26 and examining the relationship between the member corner R and the shear deformation angle γ of the PZ hardware. Therefore, incremental analysis based on the displacement history according to the test method was performed using a simple steel stiffness reduction type Tri-Linear restoring force model as shown in Fig. 33 for the rotational spring of the plastic hinge part at the yielding site of the partial structure model in Fig. 26. The analysis results are shown in Fig. 33. The amplitude of γ for each cycle of the analysis results is almost the same as the amplitude of the experimental results. Therefore, for each test specimen, ΣΔε ti is obtained from the above incremental analysis results using Equations (2) and (6), and the results of crack occurrence prediction according to Equation (11) are shown in Fig. 34.

[0110] If the M-θ relationship can be appropriately modeled, it has been confirmed that the crack generation at the yielding part can be predicted to be on the safe side within about 2 cycles at most using the simple history model shown in FIGS. 26 and 32. In addition, when predicting cracks, it is necessary to set r = 25 mm in order to avoid stress concentration at the inner corner of the end of the yielding part.

[0111] <Examination of width-thickness ratio> In order to be able to design PZ hardware corresponding to various cross-sectional shapes, a limit on the width-thickness ratio in which plastic buckling does not occur at the time of crack generation, which is the premise of the examination in Chapter 6, is necessary. Therefore, for LW1 and LW2 where plastic buckling was observed at 1 / 15 rad, a span l of the yielding part as shown in FIG. 35(a) y was used as a model of a cantilever beam with a length of 1 / 2, and FEM incremental buckling analysis was performed to attempt to reproduce plastic buckling at 1 / 15 rad by the following method.

[0112] In the FEM incremental buckling analysis, since the used program can only apply unidirectional loading, in order to represent the compressive strain due to bidirectional loading, an analysis was performed with a forced displacement 2θ that is twice the θ = 0.1 rad corresponding to R = 1 / 15 rad, and the presence or absence of buckling up to the displacement equivalent to R = 1 / 15 rad was examined. At this time, the out-of-plane deformation of the loading point was not restrained for safety-side evaluation. The material properties and mesh size are the same as in FIG. 28. The relationship between the moment at the plastic hinge position and the deformation angle θ with the forced displacement halved is shown in FIG. 35(b).

[0113] After reaching the fully plastic yield strength, as the deformation increases, the load-carrying capacity decreases due to plastic buckling on the compression side. The deformation angle θ at the start of plastic buckling obtained from the buckling analysis is about 0.06 rad for LW2, which is larger than 0.04 rad, the deformation angle θ of the plastic hinge at 1 / 30 rad converted from the shear deformation angle γ obtained from FIG. 23 by Equation (2), and it is consistent with the fact that plastic buckling occurred after the loading cycle of 1 / 30 rad in the experiment.

[0114] Examine the width-to-thickness ratio to prevent plastic buckling by the following method. When the cross-sectional modulus of the wooden ramen used in the actual design is 400 mm or more, the maximum dimension considering the required performance and fit is smaller than LW2.

[0115] If the width-to-thickness ratio is defined as (D / 2) / t, the width-to-thickness ratio and M / QD of each test piece are as shown in Table 8. Therefore, considering that the applicable range of Equation (7) is 0.8 ≦ M / QD ≦ 1.4, the span l of the yield part same as LW1 or LW2 as in the model shown in Fig. 35(c) y is set to the plate thickness of 12 mm. If a deformation angle θ at the start of plastic buckling equal to or greater than that of LW1 or LW2 can be confirmed for a specification with a larger M / QD than LW1, the limit value of the width-to-thickness ratio can be determined.

[0116]

Table 8

[0117] Add the analysis results of LW1, LW2, and the models with M / QD = 1.2 and 1.4 to Fig. 35(b). As M / QD increases, the deformation angle θ at the start of plastic buckling increases, and since the influence of the decrease in the width-to-thickness ratio is greater than the influence of the increase in the buckling length, it was confirmed by the analysis that the tendency to be less likely to buckle. Therefore, if the width-to-thickness ratio of LW2 with M / QD = 0.8 at a plate thickness of 12 mm or more using SN490B is set as the limit value, it can be judged that plastic buckling will not occur up to a repeated load of 1 / 30 rad for all specifications.

[0118] <Flow of design of PZ hardware> As described above, it was confirmed that the theoretical calculation and experimental results of the elastoplastic properties of PZ hardware are almost in agreement. Based on these, the design procedure of PZ hardware is organized and shown below. (i) Setting the joint efficiency of PZ hardware for wooden members (ii) Design the moment joint at the member end so that the moment acting on the moment joint at the member end when the yield part becomes the full plastic ultimate strength ≤ the yield moment of the moment joint at the member end (iii) Determine the shape of the yielding part using equations (2) and (3) considering the fit. (iv) Perform elastoplastic analysis based on the displacement history of the test method for the analysis model of the partial structure shown in Figure 33, and obtain the Q p -γ relationship, and use equations (2) and (6) to convert it to the Q p -ε relationship, and perform crack prediction using equation (11). (v) Determine various allowable bearing capacities of the PZ hardware based on the allowable stress of each part such as the yielding part, axial force support member, frame member, and HTB joint.

[0119] <Summary> By arranging the members by separating and independent the axial force support mechanism and the shear resistance mechanism, a partial structure test of the column-beam joint using the PZ hardware that removes the influence of the axial force on the shear yielding of the column-beam joint was carried out, and the following findings were obtained. (A) It was confirmed that the rigidity, bearing capacity, deformation performance, and energy absorption characteristics were significantly improved compared to the case of the continuous column structure with the same moment connection specification. Also, the shape of the hysteresis loop was similar to that of the steel frame ramen structure. (B) The influence of the axial force on the shear load of the frame member and the axial force support member was confirmed, but the influence of the axial force on the shear resistance of the yielding part was not confirmed. Therefore, it can be judged that the axial force has no influence on the overall shear characteristics of the PZ hardware, and since it can be designed independently for the shear force and the axial force respectively, the structural design can be simplified. (C) For the design of the PZ hardware, the yield bearing capacity and the maximum bearing capacity can be estimated almost accurately using equations (2) to (3). The initial shear rigidity can be estimated almost using the wire model in Figure 26. (D) The reduction of the bearing capacity starts when cracks occur on the tensile side of the plastic hinge part in the yielding part. In the linear cumulative damage rule using equation (5), the prediction of the bearing capacity reduction by experiment was consistent with the prediction of crack occurrence, so the effectiveness of the crack occurrence prediction method was confirmed. In the design, equations (2) and (6) are used to convert the shear deformation angle γ to the tensile edge strain ε of the plastic hinge part to obtain the strain amplitude Δη tiThe cumulative plastic tensile strain can be roughly estimated using equation (11), which is the calibration formula for cumulative plastic tensile strain. Note that when predicting the cracks mentioned above, r must be set to 25 mm to avoid stress concentration at the corners at the ends of the yielding area. (E) The plastic hinges at the yielding points of the partial frame are modeled as shown in Figures 26 and 32 using a tri-linear restoring force model with reduced steel stiffness, and an incremental analysis is performed. ti By calculating the yield point, it is possible to predict the occurrence of cracks in the yield region. As a result, it was confirmed that the occurrence of cracks is predictable, although it is on the safe side after about one cycle. (F) In order to guarantee the various calculated values, it is necessary that plastic buckling does not occur. For this reason, the width-thickness ratio ((D / 2) / t) of the yielding member must be 7.5 or less in the case of SN490B.

[0120] Based on the above findings, it can be concluded that the shape of the yield point of the test specimen in this study has superior performance in all aspects, including rigidity, strength, and deformation capacity, compared to a through-column rigid frame, and that by using PZ hardware with a similar shape of yield point in the actual design, it will be possible to predict performance without conducting experiments.

[0121] Even with DB2, which has the highest strength, the wooden members, including the moment joints, were undamaged, and since the prediction accuracy of the maximum strength of the PZ hardware was high, it can be determined that it is possible to design with even higher strength within the range where damage can be controlled.

[0122] In this test specimen, plastic deformation due to bending yielding of the beam was used at the yield point, but specifications in which shear yielding at the yield point occurs first are also possible.If the moment connection between the PZ hardware and the wood is a steel plate inserted drift pin connection, which can easily be designed as an elastic connection based on the bending strength of each member, then by joining the hardware attached to each column and beam member in advance, as shown in Figure 36, and then joining these to the axial support member and yield point with HTB when the frame is erected, it will be possible to absorb construction errors and also reduce the amount of steel used in the hardware. [Industrial Applicability]

[0123] The joining structure according to the present invention can be suitably used for a wooden ramen structure.

Explanation of reference numerals

[0124] 10 Frame member 12 Axial force support member 14 Yield member

Claims

1. A joining structure for joining upper and lower wooden column members and left and right wooden beam members orthogonal to the wooden column members, wherein an upper frame member and a lower frame member are fixed to a pair of side frame members facing each other, an axial force support member fixed between the upper frame member and the lower frame member, with respect to a frame member having a yielding member fixed to the pair of side frame members the upper and lower wooden column members are joined to the upper frame member and the lower frame member, respectively, and the left and right wooden beam members are joined to the pair of opposing side frame members.

2. The axial force support member is composed of a pair of parts with pin joints at the ends and different cross-sectional shapes at the upper and lower ends capable of supporting vertical loads, and the gap between them is wider than the thickness of the yielding member. The joining structure according to claim 1.

3. The axial force support member has a lower bending resistance performance at the part fixed to the upper frame member and the lower frame member than at the central part. The joining structure according to claim 1.

4. The yielding member is an H shape with a narrower width at the center than at the part fixed to the side frame member. The joining structure according to claim 1, and the part connecting both ends is installed horizontally.

5. The upper frame member, the lower frame member, and the pair of side frame members have an insertion plate with holes for drift pins formed on the joining side with the wooden column and the wooden beam. The joining structure according to claim 1.

6. Reinforcing bars, large screw bolts (LSB), or glued-in rods (GIR) are joined to at least one location of the upper frame member, the lower frame member, and the pair of side frame members. The joining structure according to claim 1.

7. A flange for fixing the yielding member is formed on the side frame member, and the yielding member is bolted to the flange. The joining structure according to any one of claims 1 or 2.

8. A joining member used for the column-beam joint of a wooden structure, including an upper frame member and a lower frame member joined to upper and lower columns, a pair of side frame members joined to left and right beams, an axial force support member fixed to the upper frame member and the lower frame member, having a yielding member fixed between the pair of side members, wherein the upper frame member, the lower frame member, and the pair of side frame members are respectively fixed, and the yielding member has a greater horizontal resistance force than the upper frame member, the lower frame member, and the pair of side frame members.

9. The axial force support member Two parts with an L-shaped cross-section made of equal-angled steel with one side facing the side frame member, or two square steel pipes, The joining member according to claim 8, wherein the gap between them is wider than the thickness of the yielding member.

10. The axial force support member The joining member according to claim 8, wherein the portion fixed to the upper frame member and the lower frame member has a lower bending resistance performance than the central portion.

11. The joining member according to claim 8, wherein the yielding member is an H-shape with a narrower width at the center than the portion fixed to the side frame member.

12. The joining member according to claim 8, wherein the upper frame member, the lower frame member, and the pair of side frame members are formed with an insertion plate having holes for drift pins on the joining side with the wooden column and the wooden beam.

13. The joining member according to any one of claims 8 or 9, wherein a flange for fixing the yielding member is formed on the side frame member, and the yielding member is bolted to the flange.

Images