Composite structural members
The composite structural member connects wooden materials around a steel structural member's through-hole using a pipe member, addressing the reduction in load-bearing and deformation capacity caused by drilling, thus maintaining structural integrity and workability.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- JFE STEEL CORP
- Filing Date
- 2023-07-12
- Publication Date
- 2026-05-19
AI Technical Summary
Existing methods for reinforcing steel structural members with wooden materials around circular through-holes reduce the load-bearing capacity, deformation capacity, and workability by requiring holes to be drilled in the steel, which is undesirable.
A composite structural member design that connects wooden materials around a circular through-hole in a steel structural member using a pipe member with threaded connections, eliminating the need for holes in the steel and maintaining structural integrity.
Prevents buckling and maintains load-bearing and deformation capacity while preserving workability by reinforcing the steel structural member without drilling into it, using a pipe member to connect wooden materials around the through-hole.
Smart Images
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Abstract
Description
Technical Field
[0001] The present invention relates to a composite structural member having a steel structural member with a circular through-hole and a wooden material that stiffens at least the periphery of the circular through-hole in the steel structural member.
Background Art
[0002] Conventionally, in mid-rise and high-rise buildings in Japan, concrete structural members and steel structural members have been widely used from the viewpoints of strength and cost. In recent years, however, wooden materials have also been used from the viewpoints of environmental consideration, designability, and workability. In addition, a hybrid structure combining a steel structural member and a wooden material has been proposed to take advantage of the above-mentioned respective merits.
[0003] Steel structural members such as H-beams are widely used for the beams of buildings, but the beams may deform due to external forces such as earthquakes. An example of beam deformation during an earthquake is shown in FIG. 10. FIG. 10 shows a state in which an external force is applied to a steel structural member 3 (H-beam) used as a beam and it is deformed. As shown in FIGS. 10(a) and 10(b), when an external force 19 is applied to the steel structural member 3 due to an earthquake or the like, local buckling 39 occurs in the vicinity of the joint with the column 13. When local buckling 39 occurs in the beam, the strength and deformation capacity of the beam decrease, which is dangerous.
[0004] Particularly in recent years, in order to improve the efficiency of the rigidity and strength of the beam in the strong axis direction, there is a tendency to increase the plate thickness of the flange 11 and decrease the plate thickness of the web 9, and the demand for a method of suppressing the buckling of the web 9 is increasing. In contrast, Patent Document 1 proposes a technique of applying wooden members to both surfaces of the web of a steel material and connecting the wooden members to each other with a connecting material to stiffen the web of the steel material.
[0005] Furthermore, in recent buildings, multiple through-holes are sometimes provided in the web of a beam to increase the degree of freedom for piping. An example of a steel structural member 3 with circular through-holes in the web is shown in Figure 11. As shown in Figures 11(a) and 11(b), when a circular through-hole 15 is provided in the web 9, local buckling 39 is likely to occur near the circular through-hole 15 when the steel structural member 3 deforms due to an external force. In contrast, Patent Documents 2 and 3 propose metal fittings for reinforcing through holes provided in the web of a beam. [Prior art documents] [Patent Documents]
[0006] [Patent Document 1] Japanese Patent Publication No. 2020-84406 [Patent Document 2] Patent No. 7061401 [Patent Document 3] Patent No. 3837450 [Overview of the project] [Problems that the invention aims to solve]
[0007] Figure 12 shows an example of when the steel structural member 3 in Figure 10 is stiffened using the method described in Patent Document 1. Figures 12(a) and 12(b) show an example in which wood material 5 is placed on both sides of the area in the web 9 where local buckling 39 is likely to occur, and the wood material 5 is connected to each other by a connecting member 41 inserted through the web 9 and the wood material 5. In this way, the wood material 5 suppresses out-of-plane deformation of the web 9 as shown by the dashed line in Figure 12(b), thereby increasing the load-bearing capacity and deformation capacity of the steel structural member 3.
[0008] Because the wood material 5 is lightweight and has excellent design and workability, it is useful as a member to stiffen the web 9 of the beam. However, in order to fix the wood material 5 to the web 9, it was necessary to make multiple holes 43 in the web 9 for inserting the connecting member 41.
[0009] In particular, when a wooden material 5 is placed in the circular through-hole 15 of the web 9, as shown in Figures 13(a) and 13(b), multiple holes 43 for inserting the connecting material 41 must be made around the circular through-hole 15, which reduces the load-bearing capacity, deformation capacity, and workability of the steel structural member 3, posing a problem.
[0010] The present invention was made to solve the above-mentioned problems, and aims to provide a composite structural member that can suppress buckling occurring near a circular through-hole in a steel structural member having a circular through-hole by using wood material, without drilling a hole in the steel structural member. [Means for solving the problem]
[0011] (1) The composite structural member according to the present invention comprises a steel structural member having a steel plate portion having a circular through hole, a pair of wooden materials having an opening of the same diameter or less than the circular through hole and arranged to sandwich the steel plate portion at least around the circular through hole in the steel structural member, and a pipe member inserted through the circular through hole and the opening, The invention is characterized by connecting the pair of wooden materials with the pipe member and sandwiching the steel plate portion between the pair of wooden materials.
[0012] (2) Furthermore, in the case described in (1) above, the circular through hole and the opening are of the same diameter and have female threads on the inner circumferential surfaces of both, the pipe member has a male thread that screws into the female thread, and the pair of wood materials are connected by the pipe member by screwing the male thread and the female thread, and the steel plate is sandwiched between the pair of wood materials.
[0013] (3) Furthermore, in the case described in (1) above, the circular through hole is larger in diameter than the opening and has a female thread on the inner surface of the opening, and the pipe member has a male thread on its outer surface that screws into the female thread, and the pair of wood materials are connected by the pipe member by screwing the male thread and the female thread, and the steel plate is sandwiched between the pair of wood materials.
[0014] (4) Furthermore, in the case described in (1) above, the pipe member comprises a first pipe member having an outward-facing flange portion at one end with an outer diameter larger than the opening and a male threaded portion at the other end, and a second pipe member having an outward-facing flange portion at one end with an outer diameter larger than the opening and a female threaded portion at the other end that screws into the male threaded portion. The invention is characterized in that the first pipe member and the second pipe member are inserted through the circular through hole and the opening, and the male threaded portion and the female threaded portion are screwed together, thereby connecting the pair of wooden materials with the pipe members and sandwiching the steel plate portion with the pair of wooden materials.
[0015] (5) Furthermore, in the case described in (4) above, the outward-facing flange portion is fixed to the wood material, thereby connecting the pair of wood materials with the pipe member, and the steel plate portion is sandwiched between the pair of wood materials.
[0016] (6) Furthermore, in the present invention described in (1) above, the circular through-hole is larger in diameter than the opening, the pipe member has outward-facing flange portions at both ends having an outer diameter larger than the opening and smaller in diameter than the circular through-hole, the wood material is divided into left and right halves when viewed from the front of the through-hole with the circular through-hole in between, and the pair of wood materials are connected by the pipe member by fixing the outward-facing flange portions to the wood material, thereby sandwiching the steel plate portion between the pair of wood materials. [Effects of the Invention]
[0017] In this invention, a pair of wood-based materials are connected by a pipe member inserted through a circular through-hole in a steel structural member, eliminating the need to drill new holes in the steel structural member. Therefore, the area near the circular through-hole can be reinforced with wood-based materials without reducing the load-bearing capacity, deformation capacity, and workability of the steel structural member. [Brief explanation of the drawing]
[0018] [Figure 1]It is an explanatory drawing of the composite structural member according to Embodiment 1 of the present invention. Fig. 1(a) is a front view of the web, and Fig. 1(b) is a sectional view taken along line A-A of Fig. 1(a). [Figure 2] It is a figure showing the state in which the composite structural member of Fig. 1 is deformed by an external force. Fig. 2(a) is a front view of the web, and Fig. 2(b) is a sectional view taken along line B-B of Fig. 2(a). [Figure 3] It is an explanatory drawing of the composite structural member according to another aspect of Embodiment 1 of the present invention. Fig. 3(a) is a front view of the web, and Fig. 3(b) is a sectional view taken along line C-C of Fig. 3(a). [Figure 4] It is a figure showing the state in which the composite structural member of Fig. 3 is deformed by an external force. Fig. 4(a) is a front view of the web, and Fig. 4(b) is a sectional view taken along line D-D of Fig. 4(a). [Figure 5] It is an explanatory drawing of the composite structural member according to Embodiment 2 of the present invention. Fig. 5(a) is a front view of the web, and Fig. 5(b) is a sectional view taken along line E-E of Fig. 5(a). [Figure 6] It is a sectional view of the pipe member according to Embodiment 2. [Figure 7] It is a figure showing the state in which the composite structural member of Fig. 5 is deformed by an external force. Fig. 7(a) is a front view of the web, and Fig. 7(b) is a sectional view taken along line F-F of Fig. 7(a). [Figure 8] It is an explanatory drawing of the composite structural member according to Embodiment 3 of the present invention. Fig. 8(a) is a front view of the web, and Fig. 8(b) is a sectional view taken along line G-G of Fig. 8(a). [Figure 9] It is a figure showing the state in which the composite structural member of Fig. 8 is deformed by an external force. Fig. 8(a) is a front view of the web, and Fig. 9(b) is a sectional view taken along line H-H of Fig. 9(a). [Figure 10] It is a figure showing an example of buckling during an earthquake in the case of a steel structural member (H-shaped steel) alone. Fig. 10(a) is a front view of the web, and Fig. 10(b) is a sectional view taken along line I-I of Fig. 10(a). [Figure 11] It is a figure showing an example of buckling during an earthquake in the case of a steel structural member (H-shaped steel) with a circular through-hole provided alone. Fig. 11(a) is a front view of the web, and Fig. 11(b) is a sectional view taken along line J-J of Fig. 11(a). [Figure 12] Figure 12(a) shows an example of a steel structural member being stiffened using a conventional method. Figure 12(b) is a front view of the web, and Figure 12(a) is a cross-sectional view of KK in Figure 12(a). [Figure 13] Figure 11 shows an example of a steel structural member being stiffened using a conventional method. Figure 13(a) is a front view of the web, and Figure 13(b) is a cross-sectional view of the LL of Figure 13(a). [Modes for carrying out the invention]
[0019] [Embodiment 1] A composite structural member 1 according to Embodiment 1 of the present invention will be described with reference to Figure 1. As shown in Figure 1, the composite structural member 1 of this embodiment comprises a steel structural member 3, a pair of wood materials 5, and a pipe member 7.
[0020] The steel structural member 3 is an H-shaped steel having a web 9 (the steel plate portion of the present invention) and a flange 11, and is used as a beam in a building, for example, by joining its end to a column 13 as shown in Figure 1(a). The web 9 has a circular through-hole 15 for passing pipes and the like through, and a female threaded portion 15a is formed on the inner circumferential surface of the circular through-hole 15. Around the circular through-hole 15, a pair of wooden members 5, each with an opening 17 having the same diameter as the circular through-hole 15, are arranged to sandwich the web 9. On the inner surface of the opening 17, a female threaded portion 17a is formed, similar to the circular through-hole 15.
[0021] Furthermore, a gap S is left between the flange 11 of the steel structural member 3 and the wood material 5 (see Figure 1(b)). The reason for leaving a gap S is as follows. When the steel structural member 3 deforms due to external forces caused by an earthquake, the flange 11 of the steel structural member 3 comes into contact with the wood material 5, causing in-plane bending of the wood material 5 and leading to damage to the wood material 5. In this regard, by providing a gap S between the flange 11 and the wood material 5, the flange 11 is less likely to come into contact with the wood material 5 when the steel structural member 3 deforms, thus reducing in-plane bending of the wood material 5 and preventing premature failure of the wood material 5. Furthermore, if there were no gap S, there would be a risk that the wooden material 5 could not be installed between the upper and lower flanges 11 if there was an error in the formation position of the circular through hole 15 or the opening 17. However, by setting a gap S, such construction errors can be absorbed.
[0022] The pipe member 7 is inserted through the circular through-hole 15 of the steel structural member 3 and the opening 17 of the wood material 5, and is a member that connects the pair of wood materials 5 that are arranged on both sides of the web 9. In this embodiment, the outer circumferential surface of the pipe member 7 has a male threaded portion 7a that screws into the female threaded portions 15a and 17a of the circular through hole 15 and the opening 17. By screwing the male threaded portion 7a into the female threaded portions 15a and 17a and inserting the pipe member 7 into the circular through hole 15 and the opening 17, the pipe member 7 connects the pair of wood materials 5.
[0023] Figure 2 shows the state in which the composite structural member 1, configured as described above, is deformed when external forces due to an earthquake are applied. When an external force 19 due to an earthquake is applied to the composite structural member 1, the steel structural member 3 deforms as shown in Figure 2(a). In this case, assuming that the wooden material 5 is not provided, out-of-plane deformation occurs around the circular through-hole 15 in the web 9, as shown by the dashed line in Figure 2(b). In contrast, in this embodiment, the part in question is held between a pair of wood materials 5, so out-of-plane deformation is suppressed as shown by the arrow in Figure 2(b), and buckling of the web 9 can be prevented.
[0024] As described above, in this embodiment, the pair of wood members 5, which are arranged to sandwich the web 9, are connected by screwing together the female threaded portion 17a formed in the opening 17 of the wood member 5 and the male threaded portion 7a formed on the outer surface of the pipe member 7. In the example shown in Figure 1, a female threaded portion 15a is also provided in the circular through-hole 15 of the web 9 and screwed into the pipe member 7, but the pipe member 7 only needs to be inserted through the circular through-hole 15 and screwing it in is not essential. As another aspect of this embodiment, Figure 3 shows an example in which the female threaded portion 15a is not provided in the circular through-hole 15.
[0025] The composite structural member 21 shown in Figure 3 has a configuration similar to that of the composite structural member 1 in Figure 1, but the circular through-hole 15 of the web 9 is larger in diameter than the opening 17 of the wood material 5, and the female thread portion 15a is not formed on the inner circumferential surface of the circular through-hole 15. The outer circumferential surface of the pipe member 7 and the inner circumferential surface of the opening 17 of the wood material 5 have male thread portions 7a and female thread portions 17a, respectively, as in Figure 1.
[0026] With the pipe member 7 inserted through the circular through hole 15, the male threaded portion 7a is screwed into the female threaded portion of the opening 17 of the pair of wood materials 5. As in Figure 1, the pair of wood materials 5 are connected by screwing the male threaded portion 7a of the pipe member 7 into the female threaded portion 17a of the wood material 5.
[0027] In this case as well, the area around the circular through-hole 15 in the web 9 is held in place by a pair of wooden members 5, and as shown in Figures 4(a) and 4(b), when the steel structural member 3 is deformed by an external force 19, the pair of wooden members 5 suppress out-of-plane deformation of the web 9, thereby preventing buckling of the web 9.
[0028] [Embodiment 2] A composite structural member 23 according to Embodiment 2 of the present invention will be described with reference to Figure 5. In Figure 5, parts common to composite structural members 1 and 21 of Embodiment 1 are denoted by the same reference numerals. The steel structural member 3 and the pair of wood materials 5 in the composite structural member 23 of this embodiment are mainly the same as those in Figure 1, but the female threaded portions 15a and 17a are not formed on the inner circumferential surface of the circular through hole 15 and the inner circumferential surface of the opening 17. In this embodiment, there are differences from Embodiment 1 in the configuration of the pipe member 25 and the method of connecting the pair of wood materials 5 using the pipe member 25, so these points will be explained below.
[0029] As shown in Figure 6, the pipe member 25 of this embodiment is composed of two tubular members, a first pipe member 27 and a second pipe member 29. The first pipe member 27 has an outward-facing flange portion 27a at one end, whose outer diameter is larger than the opening 17 of the wood material 5, and a male threaded portion 27b at the other end. The second pipe member 29 has an outward-facing flange portion 29a at one end, whose outer diameter is larger than the opening 17 of the wood material 5, and a female threaded portion 29b at the other end that screws into the male threaded portion 27b of the first pipe member 27.
[0030] In the composite structural member 23 of this embodiment, as shown in Figure 5(b), the first pipe member 27 and the second pipe member 29 are inserted through the circular through hole 15 of the steel structural member 3 and the opening 17 of the wood material 5, and the male threaded portion 27b and the female threaded portion 29b are screwed together. The fastening force of the first pipe member 27 and the second pipe member 29 causes the outward-facing flange portions 27a and 29a to sandwich the pair of wood materials 5, thereby connecting the pair of wood materials 5.
[0031] In this example as well, the area around the circular through-hole 15 in the web 9 is held between a pair of wooden members 5, and as shown in Figures 7(a) and 7(b), when the steel structural member 3 is deformed by an external force 19, the pair of wooden members 5 suppress out-of-plane deformation of the web 9, thereby preventing buckling of the web 9.
[0032] Alternatively, the outward-facing flange portion 27a of the first pipe member 27 and the outward-facing flange portion 29a of the second pipe member 29 may be fixed to the wood material 5. The method of fixing is not particularly limited, but for example, screw holes may be provided in the outward-facing flange portions 27a and 29a, and the outward-facing flange portions 27a and 29a may be fixed to the wood material 5 with screws.
[0033] [Embodiment 3] A composite structural member 31 according to Embodiment 3 of the present invention will be described with reference to Figure 8. In Figure 8, parts common to composite structural members 1, 21, and 23 of Embodiments 1 and 2 are denoted by the same reference numerals. In this embodiment, the steel structural member 3 in the composite structural member 31 is mainly the same as in Figure 3, and a circular through-hole 15 with a larger diameter than the opening 17 of the wood material 5 is formed in the web 9.
[0034] The pipe member 33 of this embodiment has a shape that is like an integral part of the pipe member 25 of embodiment 2, and has outward-facing flange portions 33a at both ends, the outer diameter of which is larger than the opening 17 of the wood material 5. In this example, when inserting the pipe member 33 into the circular through hole 15 of the web 9, it is necessary to pass the outward-facing flange portions 33a of the pipe member 33 through the circular through hole 15, so the outer diameter of the outward-facing flange portions 33a is made smaller than the circular through hole 15.
[0035] Furthermore, for ease of assembly, the wood material 5 in this embodiment is divided into left and right sections (divided pieces 35) on either side of the circular through-hole 15 when viewed from the front of the through-hole. The outward-facing flange portions 33a of the pipe member 33 are fixed to the divided pieces 35 of the wood material 5 with screws 37. As a result, the pair of wood materials 5 are connected by the pipe member 33, and the web 9 is sandwiched between the connected pair of wood materials 5.
[0036] In this example as well, as shown in Figures 9(a) and 9(b), when the steel structural member 3 is deformed by the external force 19, the pair of wood materials 5 suppress the out-of-plane deformation of the web 9, thereby preventing buckling of the web 9.
[0037] As described in embodiments 1 to 3 above, by connecting a pair of wooden members 5 arranged around the circular through-hole 15 so as to sandwich the web 9 with a pipe member 7 (or pipe member 25, or pipe member 33) inserted through the circular through-hole 15, buckling of the web 9 can be prevented when the steel structural member 3 deforms due to an external force 19 such as an earthquake. Furthermore, since there is no need to drill new holes in the steel structural member 3 when connecting the pair of wooden members 5, the load-bearing capacity, deformation capacity, and constructability of the steel structural member 3 are not reduced.
[0038] In the examples shown in Figures 1 to 9, the wooden material 5 was placed only near the circular through-hole 15. However, the length of the wooden material 5 can be extended to reinforce areas other than the circular through-hole 15. Furthermore, although an H-shaped steel beam was used as an example of the steel structural member 3 above, the steel structural member of the present invention can be any member with a steel plate portion having a circular through hole, and can be applied to members of other shapes such as channel steel.
[0039] Furthermore, if two or more circular through-holes 15 are provided in the web 9, one possible configuration is to reinforce the multiple circular through-holes 15 with a pair of wooden members 5 that have a length spanning the circular through-holes 15 and are provided with a number of openings 17 corresponding to the circular through-holes 15. However, when multiple circular through-holes 15 are reinforced with a pair of wooden members 5, multiple pipe members 7 pass through the pair of wooden members 5, so the bending moment acting on the wooden members 5 when an external force is applied becomes large. If there is a risk that the wooden members 5 may break due to this bending moment, it is advisable to take measures such as cutting the wooden members 5 at appropriate intervals in the direction of the material axis.
[0040] 1. Composite structural member (Embodiment 1) 3. Steel structural members 5 Wood materials 7. Pipe member (Embodiment 1) 7a Male threaded portion 9 Web 11 Flange 13 pillars 15 circular through holes 15a Female thread section 17 Opening 17a Female thread section 19 External force 21. Composite structural member (another embodiment of Embodiment 1) 23. Composite structural member (Embodiment 2) 25 Pipe member (Embodiment 2) 27 First pipe member 27a Outward flange portion 27b Male threaded section 29 Second pipe member 29a Outward-facing flange portion 29b Female thread section 31. Composite structural member (Embodiment 3) 33 Pipe member (Embodiment 3) 33a Outward flange portion 35 Split pieces 37 Bis 39 Local buckling 41 Connecting material (conventional example) 43 holes
Claims
1. A steel structural member comprising a steel plate portion having a circular through-hole, a pair of wooden materials having an opening of the same diameter or less than the circular through-hole and arranged to sandwich the steel plate portion at least around the circular through-hole in the steel structural member, and a pipe member inserted through the circular through-hole and the opening, A composite structural member characterized in that the circular through hole and the opening are of the same diameter and have female threads on the inner circumferential surfaces of both, the tubular member has a male thread on its outer circumferential surface that screws into the female thread, and the pair of wood materials are connected by the tubular member by screwing the male thread and the female thread, and the steel plate is sandwiched between the pair of wood materials.
2. A steel structural member comprising a steel plate portion having a circular through-hole, a pair of wooden materials having an opening of the same diameter or less than the circular through-hole and arranged to sandwich the steel plate portion at least around the circular through-hole in the steel structural member, and a pipe member inserted through the circular through-hole and the opening, The aforementioned pipe member comprises a first pipe member having an outward-facing flange portion at one end with an outer diameter larger than the opening and a male threaded portion at the other end, and a second pipe member having an outward-facing flange portion at one end with an outer diameter larger than the opening and a female threaded portion at the other end that screws into the male threaded portion. A composite structural member characterized in that the first pipe member and the second pipe member are inserted through the circular through hole and the opening, and the male threaded portion and the female threaded portion are screwed together, thereby connecting the pair of wood materials with the pipe members and sandwiching the steel plate portion with the pair of wood materials.
3. The composite structural member according to claim 2, characterized in that the outward-facing flange portion is fixed to the wood material, thereby connecting the pair of wood materials with the pipe member, and the steel plate portion is sandwiched between the pair of wood materials.
4. A steel structural member comprising a steel plate portion having a circular through hole, a pair of wooden materials having an opening of the same diameter or less than the circular through hole and arranged on either side of the steel plate portion at least around the circular through hole in the steel structural member, and a pipe member inserted through the circular through hole and the opening, A composite structural member characterized in that the circular through-hole is larger in diameter than the opening, the pipe member has outward-facing flange portions at both ends having an outer diameter larger than the opening and smaller in diameter than the circular through-hole, the wood material is divided into left and right halves when viewed from the front of the through-hole with the circular through-hole in between, and the pair of wood materials are connected by the pipe member by fixing the outward-facing flange portions to the wood material, and the steel plate portion is sandwiched between the pair of wood materials.