Adjustable and deformable energy-dissipating engineered bamboo-steel truss composite beam

Abstract

The present invention provides an adjustable and deformable energy-dissipating engineered bamboo-steel truss composite beam, which comprises an engineered bamboo beam and an adjustable steel truss; the adjustable steel truss includes an adjustable circular steel pipe lower chord, circular steel pipe web members and angle steel upper chords; the angle steel upper chords are fixed on both sides of the bottom of the engineered bamboo beam, and the circular steel pipe web members are connected between the two angle steel upper chords and the adjustable circular steel pipe lower chord; the adjustable circular steel pipe lower chord includes a plurality of circular steel pipe lower chords and a number of first length adjustment components; two adjacent circular steel pipe web members on both sides of the first length adjustment component include a second length adjustment component. The adjustable and deformable energy-dissipating engineered bamboo-steel truss composite beam of the present invention can give full play to the mechanical property advantages of both steel and engineered bamboo materials, realize the application of engineered bamboo in long-span structures, and at the same time solve the problem of excessive deformation caused by creep during the long-term load-bearing process of engineered bamboo flexural members by adjusting the overall vertical deformation of the composite truss beam.

Description

Technical Field

[0001] The invention relates to the field of structural engineering, and in particular to an energy-dissipating engineering bamboo-steel truss composite beam with adjustable deformation. Background Art

[0002] The construction industry has an important impact on global sustainable development and climate change response. In the context of developing green and environmentally friendly ecological buildings, my country, as a country with the richest bamboo forest resources and the deepest bamboo cultural heritage in the world, has natural advantages and great potential in promoting bamboo building materials and bamboo structure buildings. As a low-carbon, renewable, easily degradable, thermally insulating, lightweight and earthquake-resistant biomass material, its promotion and application in the construction industry is of great significance to environmental protection.

[0003] With the continuous advancement of processing technology, the application of engineered bamboo represented by glued bamboo and reconstructed bamboo in the construction field has become more and more extensive. Engineered bamboo structures have achieved standardization and modernization on the basis of retaining ecological greenness, which meets the industry development needs of green and low-carbon buildings and building industrialization. There is great room for development in using them in engineering load-bearing structures.

[0004] Engineering bamboo has high tensile and compressive strength in the direction of the grain, but is limited by the elastic modulus of the material. The cross-section of engineering bamboo bending members is generally controlled by deformation, and the material strength cannot be fully utilized. It is also difficult to use in large-span structures. Combining it with steel to make a composite structure can fully utilize the mechanical properties of the two materials and improve the utilization rate of the material. When used in large-span spatial structures, energy dissipation and shock absorption are also issues that need to be considered during design.

[0005] On the other hand, under long-term load, bamboo has significant creep characteristics, which makes the deflection of engineering bamboo bending members increase with the extension of load time during long-term load-bearing work, which has an important impact on normal use function. Take necessary technical measures to control the long-term deformation of engineering bamboo components, and make timely adjustments when the deformation exceeds the standard to ensure the long-term safety and normal use of engineering bamboo structures. Summary of the invention

[0006] In view of the deficiencies in the above-mentioned prior art, the present invention provides an energy-absorbing engineering bamboo-steel truss composite beam with adjustable deformation, which can give full play to the mechanical property advantages of both steel and engineering bamboo, realize the application of engineering bamboo in large-span structures, and at the same time solve the problem of excessive deformation caused by creep during long-term load-bearing of engineering bamboo bending members by adjusting the overall vertical deformation of the composite truss beam.

[0007] To achieve the above object, the present invention provides an adjustable and deformable energy-dissipating engineered bamboo-steel truss composite beam, comprising an engineered bamboo beam and an adjustable steel truss; the adjustable steel truss includes an adjustable circular steel pipe lower chord, a plurality of circular steel pipe web members, and two angle steel upper chords; the angle steel upper chords and the adjustable circular steel pipe lower chord are arranged along the longitudinal direction of the engineered bamboo beam, and the angle steel upper chords are fixed to both sides of the bottom of the engineered bamboo beam. The adjustable circular steel pipe lower chord is arranged below the two angle steel upper chords, and the circular steel pipe web members are connected between the two angle steel upper chords and the adjustable circular steel pipe lower chord; the adjustable circular steel pipe lower chord includes a plurality of circular steel pipe lower chords and a number of first length adjustment components, and the circular steel pipe lower chords are connected end to end through the first length adjustment components to form the adjustable circular steel pipe lower chord; two adjacent circular steel pipe web members on both sides of the first length adjustment component include a second length adjustment component.

[0008] Preferably, the first length adjustment component is arranged in the middle of the two connection parts between the adjacent circular steel pipe web members on both sides and the circular steel pipe lower chord.

[0009] Preferably, the angle steel upper chord and the engineered bamboo beam are connected and fixed by self-tapping screws. The self-tapping screws are vertically driven into the engineered bamboo beam from the lower side of the angle steel upper chord, and the angle steel upper chord is pre-opened at the position where the self-tapping screws are arranged.

[0010] Preferably, the first length adjustment component includes two first screws and a first steel sleeve; the whole length of the first screw is provided with external threads; the inner ends of the two first screws are threaded in opposite directions and are inserted and screwed into the two ends of the first steel sleeve, and the outer ends of the two first screws are respectively inserted and screwed into the adjacent two circular steel pipe lower chords; the threads inside the first steel sleeve and the circular steel pipe lower chord cooperate with the external threads of the corresponding first screws.

[0011] Preferably, the second length adjustment component is arranged in the middle of the corresponding circular steel pipe web member.

[0012] Preferably, the circular steel pipe web member where the second length adjustment component is located includes two circular steel pipe web member segments; the second length adjustment component includes two second screws and a second steel sleeve; the whole length of the second screw is provided with external threads; the inner ends of the two second screws are threaded in opposite directions and are inserted and screwed into the two ends of the second steel sleeve, and the outer ends of the two second screws are respectively inserted and screwed into the corresponding two circular steel pipe web member segments; the threads inside the second steel sleeve and the circular steel pipe web member segments cooperate with the external threads of the corresponding second screws.

[0013] Preferably, the space between the two second screws inside the second steel sleeve is filled with high-viscosity elastic rubber.

[0014] Due to the adoption of the above technical solutions, the present invention has the following beneficial effects:

[0015] An adjustable and deformable energy-dissipating engineered bamboo-steel composite truss beam provided by the present invention can make full use of the mechanical property advantages of high tensile strength of steel and good compressive ductility of engineered bamboo, improve the utilization rate of the two materials, and provide a solution for the application of engineered bamboo in large-span space structures. The highly viscoelastic rubber filled inside the second steel sleeve can dissipate energy under seismic action, achieving the effect of energy dissipation and shock absorption.

[0016] On the other hand, the present invention can adjust the length of the adjustable circular steel pipe lower chord by rotating the first steel sleeve on the adjustable circular steel pipe lower chord, and then adjust the overall vertical deformation of the composite truss beam, avoiding the problem of excessive deformation caused by creep during the long-term load-bearing process of the engineered bamboo flexural member, and ensuring the long-term safety and normal use of the engineered bamboo structure. When adjusting the deformation, first, with the assistance of the second length adjustment component, the adjustable circular steel pipe lower chord is lifted to a certain extent. After adjusting the adjustable circular steel pipe lower chord to a straight state, then adjust the adjustable circular steel pipe lower chord, avoiding the problem that the local deformation of the adjustable circular steel pipe lower chord at the connection is too large to be adjusted after long-term use, and the operation is simple and efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic structural diagram of an adjustable and deformable energy-dissipating engineered bamboo-steel truss composite beam according to an embodiment of the present invention;

[0018] Figure 2 is a front view of an adjustable and deformable energy-dissipating engineered bamboo-steel truss composite beam according to an embodiment of the present invention;

[0019] Figure 3 is a side view of an adjustable and deformable energy-dissipating engineered bamboo-steel truss composite beam according to an embodiment of the present invention;

[0020] Figure 4 is a schematic connection structure diagram of a first length adjustment component according to an embodiment of the present invention;

[0021] Figure 5 is a schematic connection structure diagram of a second length adjustment component according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] The following provides a preferred embodiment of the present invention according to the drawings Figures 1 to 5 , and gives a detailed description to better understand the functions and features of the present invention.

[0023] Please refer to Figures 1 to 5, An adjustable and deformable energy-dissipating engineered bamboo-steel truss composite beam according to an embodiment of the present invention includes an engineered bamboo beam 1 and an adjustable steel truss 2; the adjustable steel truss 2 includes an adjustable circular steel pipe lower chord 21, a plurality of circular steel pipe web members 22, and two angle steel upper chords 23; the angle steel upper chords 23 and the adjustable circular steel pipe lower chord 21 are arranged along the grain direction of the engineered bamboo beam 1, and the angle steel upper chords 23 are fixed to both sides of the bottom of the engineered bamboo beam 1. The adjustable circular steel pipe lower chord 21 is arranged below the two angle steel upper chords 23, and the circular steel pipe web members 22 are connected between the two angle steel upper chords 23 and the adjustable circular steel pipe lower chord 21; the adjustable circular steel pipe lower chord 21 includes a plurality of circular steel pipe lower chords and a number of first length adjustment components 3. The circular steel pipe lower chords are connected end to end through the first length adjustment components 3 to form the adjustable circular steel pipe lower chord 21; two of the four circular steel pipe web members 22 adjacent to both sides of the first length adjustment component 3 include a second length adjustment component 4.

[0024] In this embodiment, the engineered bamboo beam 1 is made of glued bamboo, and the adjustable steel truss 2 is made of Q235B grade steel. The engineered bamboo beam 1 has a rectangular cross-section with a cross-sectional size of 250 mm × 90 mm and is located above the adjustable steel truss 2.

[0025] The circular steel pipe web members 22 are connected to the angle steel upper chords 23 and the adjustable circular steel pipe lower chord 21 by welding. The adjustable circular steel pipe lower chord 21 of the adjustable steel truss 2 is made of hollow circular steel pipe, and the circular steel pipe web members 22 are made of hollow circular steel pipe, and the angle steel upper chords 23 are made of L40×3 angle steel.

[0026] The first length adjustment component 3 is arranged in the middle of the two connection parts between the circular steel pipe web members 22 adjacent to both sides and the circular steel pipe lower chord.

[0027] The angle steel upper chords 23 and the engineered bamboo beam 1 are connected and fixed by self-tapping screws 5. The self-tapping screws 5 are vertically driven into the engineered bamboo beam 1 from the lower side of the angle steel upper chords 23. The angle steel upper chords 23 are pre-drilled with holes with a diameter of 10 mm at the positions where the self-tapping screws 5 are provided.

[0028] In this embodiment, self-tapping screws 5 with a diameter of 8 mm and a length of 65 mm are selected; the self-tapping screws 5 are arranged in double rows symmetrically with a spacing of 250 mm along the length direction of the truss beam.

[0029] The first length adjustment assembly 3 includes two first screw rods 31 and a first steel sleeve 32; the entire length of the first screw rod 31 is provided with external threads, and the first screw rod 31 is 80 mm long; the inner ends of the two first screw rods 31 are threaded through and screwed into the two ends of the first steel sleeve 32 in opposite thread directions, and the outer ends of the two first screw rods 31 are respectively threaded through and screwed into the adjacent two circular steel tube lower chord rods, with an insertion length of 40 mm; the threads inside the first steel sleeve 32 and the circular steel tube lower chord rod cooperate with the external threads of the corresponding first screw rod 31.

[0030] The second length adjustment assembly 4 is arranged in the middle of the corresponding circular steel tube web member 22.

[0031] The circular steel tube web member 22 where the second length adjustment assembly 4 is located includes two circular steel tube web member segments; the second length adjustment assembly 4 includes two second screw rods 41 and a second steel sleeve 42; the entire length of the second screw rod 41 is provided with external threads, and the second screw rod 41 is 50 mm long; the inner ends of the two second screw rods 41 are threaded through and screwed into the two ends of the second steel sleeve 42 in opposite thread directions, and the outer ends of the two second screw rods 41 are respectively threaded through and screwed into the corresponding two circular steel tube web member segments, with an insertion length of 25 mm; the threads inside the second steel sleeve 42 and the circular steel tube web member segment cooperate with the external threads of the corresponding second screw rod 41.

[0032] High-viscosity elastic rubber 43 is filled in the gap between the two second screw rods 41 inside the second steel sleeve 42.

[0033] When it is necessary to adjust the overall deformation of the combined truss beam during use, first rotate the second steel sleeve 42 on the circular steel tube web member 22 to tighten it, so that the adjustable circular steel tube lower chord rod 21 can be lifted to a certain extent. Then, rotate the second steel sleeves 42 on the four circular steel tube web members 22 at the same node successively for adjustment. After adjusting the adjustable circular steel tube lower chord rod 21 to be close to a straight state, then rotate the first steel sleeve 32 on the adjustable circular steel tube lower chord rod 21 to adjust the total length of the adjustable circular steel tube lower chord rod 21, and further adjust the overall vertical deformation of the combined truss beam.

[0034] When it is necessary to reduce the vertical deformation of the combined truss beam, the first steel sleeve 32 can be rotated in the direction of tightening the screw rod to reduce the total length of the adjustable circular steel tube lower chord rod 21, and further cause the combined truss beam to arch upward as a whole.

[0035] The present invention can dissipate energy through the highly viscoelastic rubber 43 filled inside the second steel sleeve 42 under earthquake action. Meanwhile, with the assistance of the first length adjustment assembly 3, the length of the adjustable circular steel pipe lower chord 21 can be adjusted by rotating the second steel sleeve 42, thereby adjusting the overall vertical deformation of the composite truss beam and avoiding the problem of excessive deformation caused by creep during the long-term loading process of the engineered bamboo flexural member. The present invention makes full use of the mechanical property advantages of steel and engineered bamboo, improves the material utilization rate, is applicable to large-span space structures, integrates energy dissipation and shock absorption with deformation adjustment, and has good development and application prospects in prefabricated modern bamboo and wood structures.

[0036] The present invention has been described in detail with reference to the embodiments accompanied by drawings. Those of ordinary skill in the art can make various variations to the present invention according to the above description. Therefore, certain details in the embodiments should not constitute a limitation to the present invention, and the protection scope of the present invention will be defined by the scope defined in the appended claims.

Claims

1. An adjustable and deformable energy-dissipating engineered bamboo-steel truss composite beam, characterized in that, It includes an engineered bamboo beam (1) and an adjustable steel truss (2); the adjustable steel truss (2) includes an adjustable circular steel pipe lower chord (21), multiple circular steel pipe web members (22) and two angle steel upper chords (23); the angle steel upper chords (23) and the adjustable circular steel pipe lower chord (21) are arranged along the grain direction of the engineered bamboo beam (1), and the angle steel upper chords (23) are fixed to both sides of the bottom of the engineered bamboo beam (1), the adjustable circular steel pipe lower chord (21) is arranged below between the two angle steel upper chords (23), and the circular steel pipe web members (22) are connected between the two angle steel upper chords (23) and the adjustable circular steel pipe lower chord (21); the adjustable circular steel pipe lower chord (21) includes a plurality of circular steel pipe lower chords and several first length adjustment components (3), and the circular steel pipe lower chords are connected end to end through the first length adjustment components (3) to form the adjustable circular steel pipe lower chord (21); the four circular steel pipe web members (22) adjacent to both sides of the first length adjustment component (3) include a second length adjustment component (4). The first length adjustment component (3) is arranged in the middle of the connection parts of the two adjacent circular steel pipe web members (22) on both sides and the circular steel pipe lower chord. The angle steel upper chord (23) and the engineered bamboo beam (1) are connected and fixed by self-tapping screws (5), the self-tapping screws (5) are vertically driven into the engineered bamboo beam (1) from the lower side of the angle steel upper chord (23), and the angle steel upper chord (23) is pre-opened at the position where the self-tapping screws (5) are arranged.

2. The adjustable and deformable energy-dissipating engineered bamboo-steel truss composite beam according to claim 1, wherein The first length adjustment component (3) includes two first screw rods (31) and a first steel sleeve (32); the whole length of the first screw rod (31) is provided with external threads; the inner ends of the two first screw rods (31) are threaded in opposite directions and are inserted and screwed into both ends of the first steel sleeve (32), and the outer ends of the two first screw rods (31) are respectively inserted and screwed into the adjacent two circular steel pipe lower chords; the threads inside the first steel sleeve (32) and the circular steel pipe lower chord are matched with the external threads of the corresponding first screw rod (31).

3. The adjustable and deformable energy-dissipating engineered bamboo-steel truss composite beam according to claim 1, wherein The second length adjustment component (4) is arranged in the middle of the corresponding circular steel pipe web member (22).

4. The adjustable and deformable energy-dissipating engineered bamboo-steel truss composite beam according to claim 1, wherein The circular steel pipe web member (22) where the second length adjustment component (4) is located includes two circular steel pipe web member segments; the second length adjustment component (4) includes two second screw rods (41) and a second steel sleeve (42); the whole length of the second screw rod (41) is provided with external threads; the inner ends of the two second screw rods (41) are threaded in opposite directions and are inserted and screwed into both ends of the second steel sleeve (42), and the outer ends of the two second screw rods (41) are respectively inserted and screwed into the corresponding two circular steel pipe web member segments; the threads inside the second steel sleeve (42) and the circular steel pipe web member segments are matched with the external threads of the corresponding second screw rod (41).

5. The adjustable and deformable energy-dissipating engineered bamboo-steel truss composite beam according to claim 4, wherein High-viscosity elastic rubber (43) is filled in the gap between the two second screw rods (41) inside the second steel sleeve (42).

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