Shear connector with combined action of steel and concrete

Abstract

The utility model relates to a shearing force connecting piece under the combined action of steel and concrete. The shearing force connecting piece comprises a steel beam, cold-bent S-shaped steel and bent steel bars. The cold-bent S-shaped steel is fixedly arranged at the top of the steel beam, the bent steel bar is fixedly arranged at the upper part of the cold-bent S-shaped steel, the cold-bent S-shaped steel is S-shaped five-section steel, and the bent steel bar is omega-shaped five-section steel bar. The combined mode of the cold-bending S-shaped steel and the bent steel bars has the characteristics of a rigid shearing force connecting piece and a perforated steel plate connecting piece, the steel plate and the concrete act together to achieve a better shearing resistance effect, and in addition, the concrete plate can be effectively prevented from being lifted up on the steel beam.

Description

Technical Field

[0001] The utility model relates to the field of bridge engineering, and more specifically to a shear connector for joint action of steel and concrete. Background Art

[0002] The steel-concrete composite structure makes full use of the material properties of steel and concrete. Compared with reinforced concrete beams, the amount of wet work on site is reduced and the ductility is greatly improved. Compared with steel beams, the overall stability and local stability are enhanced, the durability is improved, and the dynamic performance is improved.

[0003] Shear connectors are key components to ensure that steel beams and concrete flanges work together. Shear connectors can be divided into rigid connectors and flexible connectors according to their deformation capacity. Flexible connectors have lower rigidity, and the shear force acting on the contact surface will cause them to deform. When a certain amount of slip occurs between the concrete slab and the steel beam, their shear bearing capacity will not decrease; rigid connectors are prone to cause higher stress concentration in the surrounding concrete, causing concrete to be crushed or sheared. Rigid connectors are stiffer than flexible connectors and have higher strength. As a classic rigid shear connector, steel connectors rely on the compression surface of the steel plate to withstand the out-of-plane shear force; as a new form of shear connector, perforated steel plate connectors have stronger shear stiffness and fatigue performance than flexible connectors such as welded nails. They are generally arranged continuously along the longitudinal direction of the steel beam, and rely on the shear effect of the concrete in the hole to resist the longitudinal shear force. Utility Model Content

[0004] The technical problem to be solved by the utility model is to provide a shear connector for co-acting steel and concrete, which fully combines the advantages of a rigid shear connector and a perforated steel plate shear connector to better achieve the shear resistance effect.

[0005] The technical solution adopted by the utility model to solve the technical problem is: constructing a shear connector for co-acting steel and concrete, comprising a steel beam, a cold-bent S-shaped steel and a bent steel bar; the cold-bent S-shaped steel is fixedly arranged on the top of the steel beam, the bent steel bar is fixedly arranged on the upper part of the cold-bent S-shaped steel, the cold-bent S-shaped steel is a five-segment steel in an S shape, and the bent steel bar is a five-segment steel in an Ω shape.

[0006] According to the above scheme, the cold-bent S-shaped steel is cold-bent four times to form five sections of S-shaped steel: the first section of cold-bent S-shaped steel, the second section of cold-bent S-shaped steel, the third section of cold-bent S-shaped steel, the fourth section of cold-bent S-shaped steel and the fifth section of cold-bent S-shaped steel.

[0007] According to the above scheme, a reserved circular hole with a diameter of d2 is set at the center of the first section of cold-bent S-shaped steel, a reserved circular hole with a diameter of d2 is set at the center of the fifth section of cold-bent S-shaped steel, and a reserved semicircular hole with a diameter of d3 is set at the center of the top of the third section of cold-bent S-shaped steel.

[0008] According to the above scheme, the diameter of the bent steel bar is d1; the bent steel bar is bent four times into five sections of Ω-shaped steel bars: the first section of bent steel bar, the second section of bent steel bar, the third section of bent steel bar, the fourth section of bent steel bar and the fifth section of bent steel bar; the length of the first section of bent steel bar is l2, the length of the second section of bent steel bar is l3, the length of the third section of bent steel bar is l4, the length of the fourth section of bent steel bar is l5, and the length of the fifth section of bent steel bar is l6. The length of the first section of bent steel bar is the same as the length of the fifth section of bent steel bar, the length of the second section of bent steel bar is the same as the length of the fourth section of bent steel bar, the length of the first section of bent steel bar is greater than the length of the second section of bent steel bar, that is, l2=l6>l3=l5, the height of the second section of bent steel bar is determined according to the height of the cold-bent S-shaped steel, l3=l5=0.5h1, and the length of the third section of bent steel bar is the same as the length of each small section of the cold-bent S-shaped steel, that is, l4=l1.

[0009] According to the above scheme, the height of the cold-bent S-shaped steel is h1, the thickness of the cold-bent S-shaped steel is t1 and t1≥12mm; the lengths of the first section of cold-bent S-shaped steel, the second section of cold-bent S-shaped steel, the third section of cold-bent S-shaped steel, the fourth section of cold-bent S-shaped steel and the fifth section of cold-bent S-shaped steel are all l1, the diameter of the bent steel bar is d1, the diameter d2 of the reserved circular hole in the first section of cold-bent S-shaped steel> the diameter d1 of the bent steel bar; the diameter d3 of the semicircular hole is the same as the diameter d1 of the bent steel bar.

[0010] According to the above solution, the two opening directions of the cold-bent S-shaped steel are along the longitudinal shear direction of the composite beam.

[0011] According to the above scheme, the first section of bent steel bars and the fifth section of bent steel bars are respectively inserted into the reserved circular holes of the first section of cold-bent S-shaped steel and the fifth section of cold-bent S-shaped steel, and the third section of bent steel bars is erected on the reserved semicircular holes of the third section of cold-bent S-shaped steel and fixedly connected.

[0012] The implementation of the shear connector of the utility model in which steel and concrete act together has the following beneficial effects:

[0013] 1. The utility model has high rigidity and high shear resistance. The bent steel bars are welded to the cold-bent S-shaped steel, which can effectively resist the lifting of the concrete slab on the steel beam. When it is applied to bridges with large cross-sections, it can also effectively resist the lateral shear force.

[0014] 2. The first and last sections of the bent steel bar inserted into the reserved circular hole of the cold-bent S-shaped steel are exactly located at the center of the reserved circular hole, and a perforated steel plate connector can be formed at the same time, that is, it has the characteristics of a rigid shear connector and a perforated steel plate connector. After the construction is completed, the cold-bent S-shaped steel and the concrete in the hole jointly resist the shear force;

[0015] 3. The stress and displacement generated by the utility model under the same external force conditions are smaller, and the ability to resist damage is stronger. The concrete in the shear connector hole also plays a certain shear resistance role. Theoretically, the stress and displacement values ​​generated in actual application are smaller than the analysis values ​​of this time, and the effect is better. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0017] Figure 1 It is a schematic diagram of the overall structure in the embodiment of the utility model;

[0018] Figure 2 It is a schematic diagram of some steel beams in the embodiment of the utility model;

[0019] Figure 3 to Figure 5 This is a schematic diagram of cold-bent S-shaped steel and hole opening processing in an embodiment of the utility model;

[0020] Figure 6-7 It is a schematic diagram of a bent steel bar in an embodiment of the utility model;

[0021] Figure 8-Figure 9 It is a schematic diagram of the installation and welding positions of the bent steel bars and the cold-bent S-shaped steel in the embodiment of the utility model;

[0022] Fig.10 A schematic diagram of the external force application direction and boundary condition setting of a cold-bent "X"-shaped rigid shear connector with the same overall length and width as the shear connector proposed by the utility model;

[0023] Fig.11 A schematic diagram of the external force application direction and boundary condition setting of a cold-bent "X"-shaped rigid shear connector when the amount of steel used is the same as that of the shear connector proposed in the utility model;

[0024] Fig.12 A schematic diagram of the external force application direction and boundary condition setting of the shear connector proposed by the utility model;

[0025] Fig.13 A schematic diagram of stress analysis results of a cold-bent "X"-shaped rigid shear connector with the same overall length and width as the shear connector proposed by the utility model;

[0026] Fig.14A schematic diagram of stress analysis results of a cold-bent "X"-shaped rigid shear connector with the same steel amount as the shear connector proposed in the utility model;

[0027] Fig.15 Schematic diagram of stress analysis results of the shear connector proposed by the utility model;

[0028] Fig.16 A schematic diagram of the displacement analysis results of a cold-bent "X"-shaped rigid shear connector with the same overall length and width as the shear connector proposed by the utility model;

[0029] Fig.17 It is a schematic diagram of the displacement analysis results of a cold-bent "X"-shaped rigid shear connector with the same steel amount as the shear connector proposed in the utility model;

[0030] Fig.18 Schematic diagram of displacement analysis results of the shear connector proposed by the utility model;

[0031] In the figure: 1. steel beam, 2. cold-bent S-shaped steel, 3. bent steel bars, 201. first section of cold-bent S-shaped steel, 202. second section of cold-bent S-shaped steel, 203. third section of cold-bent S-shaped steel, 204. fourth section of cold-bent S-shaped steel, 205. fifth section of cold-bent S-shaped steel, 206. reserved circular hole in first section of cold-bent S-shaped steel, 207. reserved semicircular hole in second section of cold-bent S-shaped steel, 208. reserved circular hole in fifth section of cold-bent S-shaped steel, 301. first section of bent steel bars, 302. second section of bent steel bars, 303. third section of bent steel bars, 304. fourth section of bent steel bars, 305. fifth section of bent steel bars. DETAILED DESCRIPTION

[0032] In order to have a clearer understanding of the technical features, purposes and effects of the present utility model, the specific implementation methods of the present utility model are now described in detail with reference to the accompanying drawings.

[0033] like Figure 1-18 As shown, the shear connector for the combined action of steel and concrete of the utility model comprises a steel beam 1, a cold-bent S-shaped steel 2 and a bent steel bar 3; the cold-bent S-shaped steel 2 is fixedly arranged on the top of the steel beam 1, and the bent steel bar 3 is fixedly arranged on the upper part of the cold-bent S-shaped steel 2. The cold-bent S-shaped steel 2 is a five-segment steel in an S shape, and the bent steel bar 3 is a five-segment steel bar in an Ω shape. In this embodiment, the upper flange length of the steel beam 1 is 1000 mm.

[0034] The cold-bent S-shaped steel 2 is cold-bent four times to form five sections of S-shaped steel: the first section of cold-bent S-shaped steel 201, the second section of cold-bent S-shaped steel 202, the third section of cold-bent S-shaped steel 203, the fourth section of cold-bent S-shaped steel 204 and the fifth section of cold-bent S-shaped steel 205. A first section of cold-bent S-shaped steel reserved circular hole 206 with a diameter of d2 is provided at the center of the first section of cold-bent S-shaped steel 201, a fifth section of cold-bent S-shaped steel reserved circular hole 208 with a diameter of d2 is provided at the center of the fifth section of cold-bent S-shaped steel 205, and a third section of cold-bent S-shaped steel reserved semicircular hole 207 with a diameter of d3 is provided at the top center of the third section of cold-bent S-shaped steel 203. The cold-formed S-shaped steel 2 is divided into five sections, each section has the same length, the thickness of the cold-formed S-shaped steel 2 satisfies t1≥12mm, the diameter of the reserved circular hole satisfies d2>d1, and the diameter of the reserved semicircular hole satisfies d3=d1. In this embodiment, the thickness t1=16mm, the height h1=300mm, the length of each small section l1=300mm, d2=45mm, and d3=20mm. The two opening directions of the cold-formed S-shaped steel 2 are along the longitudinal shear direction of the composite beam.

[0035] The diameter of the bent steel bar 3 is d1; the bent steel bar 3 is bent three times into five sections of steel bars in an Ω shape: the first section of the bent steel bar 301, the second section of the bent steel bar 302, the third section of the bent steel bar 303, the fourth section of the bent steel bar 304 and the fifth section of the bent steel bar 305; the length of the first section of the bent steel bar 301 is l2, the length of the second section of the bent steel bar is l3, the length of the third section of the bent steel bar 303 is l4, the length of the fourth section of the bent steel bar 304 is l5, the length of the fifth section of the bent steel bar 305 is l6, and the length of the first section of the bent steel bar 301 is l2, the length of the second section of the bent steel bar is l3, the length of the third section of the bent steel bar 303 is l4, the length of the fourth section of the bent steel bar 304 is l5, the length of the fifth section of the bent steel bar 305 is l6, and the length of the first section of the bent steel bar 301 is l2, the length of the second section of the bent steel bar is l3, the length of the third section of the bent steel bar 303 is l4, the length of the fourth section of the bent steel bar 304 is l5, the length of the fifth section of the bent steel bar 305 is l6, and the length of the first section of the bent steel bar 301 is l2, the length of the second section of the bent steel bar 302 ... The length of the first curved steel bar 301 is the same as the length of the fifth curved steel bar 305. The length of the second curved steel bar 302 is the same as the length of the fourth curved steel bar 304. The length of the first curved steel bar 301 is greater than the length of the second curved steel bar 302, i.e., l2=l6>l3=l5. The height of the second curved steel bar 302 is determined according to the height of the cold-bent S-shaped steel 2, l3=l5=0.5h1. The length of the third curved steel bar 303 is the same as the length of each small section of the cold-bent S-shaped steel 2, i.e., l4=l1. The curved steel bar 3 is divided into five sections, and the lengths of the sections satisfy l2=l6>l3=l5, l4=l1. In this embodiment, the diameter d1=20mm, the lengths of the first and fifth sections are l2=l6=180mm, the lengths of the second and fourth sections are l3=l5=150mm, and the length of the third section is l4=l1=300mm.

[0036] The height of the cold-bent S-shaped steel 2 is h1, the thickness of the cold-bent S-shaped steel 2 is t1 and t1≥12mm; the lengths of the first section of cold-bent S-shaped steel 201, the second section of cold-bent S-shaped steel 202, the third section of cold-bent S-shaped steel 203, the fourth section of cold-bent S-shaped steel 204 and the fifth section of cold-bent S-shaped steel 205 are all l1, the diameter d1 of the bent steel bar 3, the diameter d2 of the reserved circular hole 206 of the first section of cold-bent S-shaped steel> the diameter d1 of the bent steel bar 3; the diameter d3 of the semicircular hole is the same as the diameter d1 of the bent steel bar 3.

[0037] Insert the first and last sections of the bent steel bar 3 into the reserved circular holes of the first and last sections of the cold-bent S-shaped steel 2, and place the third section of the bent steel bar 3 on the reserved semicircular hole of the cold-bent S-shaped steel 2 and weld it there by manual welding to obtain a shear connector for the joint action of steel and concrete. The direction of the shear connector is that the two opening directions of the cold-bent S-shaped steel 2 are along the longitudinal shear direction of the composite beam, and the connector is welded to the steel beam 1 along this direction.

[0038] Finite element analysis was performed on the steel plate part of the utility model and a cold-bent "X"-shaped rigid shear connector proposed in application number CN 202110609140.9. In this simulation, the steel bar is used to resist the lifting of the concrete slab, and the force on it is not considered. A uniform force of 100kN is applied to the steel plates of the three models to simulate the shear force. This simulation only takes part of the beam ends near the shear connector, so restrictions are imposed on the left, right and lower ends of the steel beam 1. The settings of external forces and boundary conditions are as follows: Figure 10 to Figure 12 The analysis results are shown in Figure 7 and Figure 8 As shown, Fig.13 , Fig.16 The stress analysis results and displacement analysis results of the cold-bent "X"-shaped rigid shear connector with the same overall length and width as the shear connector proposed in the utility model are shown in the figure. Fig.14 , Fig.17 The stress analysis results and displacement analysis results of the cold-bent "X"-shaped rigid shear connector with the same steel content as the shear connector proposed in the utility model are as follows: Fig.15 , Fig.18 The stress analysis results and displacement analysis results of the shear connector proposed in the present invention, and the dimensions are the same as those in the above-mentioned implementation mode.

[0039] The analysis results show that the maximum stress generated by the connector proposed by the utility model is 1 / 3 times that of the cold-bent "X" shaped shear connector, and the maximum displacement generated is 1 / 8 to 1 / 5 times that of the cold-bent "X" shaped shear connector. From the analysis results of the steel plate alone, it can be seen that under the same conditions, the shear connector proposed by the utility model generates smaller stress and displacement and has better performance. In addition, the shear connector proposed by the utility model also has the characteristics of the perforated steel plate connector. The concrete in the hole can simultaneously produce shear resistance, and the steel plate and concrete work together to achieve a better shear resistance effect.

[0040] The embodiments of the utility model are described above in conjunction with the accompanying drawings, but the utility model is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the enlightenment of the utility model, ordinary technicians in this field can also make many forms without departing from the scope of protection of the utility model and the claims, which all fall within the protection of the utility model.

Claims

1. A shear connector for steel and concrete, characterized in that: It includes a steel beam, a cold-bent S-shaped steel and a bent steel bar; the cold-bent S-shaped steel is fixedly arranged on the top of the steel beam, the bent steel bar is fixedly arranged on the upper part of the cold-bent S-shaped steel, the cold-bent S-shaped steel is five sections of S-shaped steel, and the bent steel bar is five sections of Ω-shaped steel bar.

2. The steel-concrete shear connector according to claim 1, characterized in that: The cold-bent S-shaped steel is cold-bent four times to form five sections of S-shaped steel: a first section of cold-bent S-shaped steel, a second section of cold-bent S-shaped steel, a third section of cold-bent S-shaped steel, a fourth section of cold-bent S-shaped steel and a fifth section of cold-bent S-shaped steel.

3. The steel-concrete shear connector according to claim 2, characterized in that: The first section of cold-bent S-shaped steel is provided with a reserved circular hole at the center of the first section of cold-bent S-shaped steel and has a diameter of The fifth section of cold-bent S-shaped steel is provided with a reserved circular hole at the center of the fifth section of cold-bent S-shaped steel and the diameter is The third section of cold-bent S-shaped steel is provided with a reserved semicircular hole at the top center of the third section of cold-bent S-shaped steel and the diameter is .

4. The steel-concrete shear connector according to claim 3, characterized in that: The diameter of the bent steel bar is The bent steel bar is bent four times into five sections of Ω-shaped steel bars: the first section of bent steel bars, the second section of bent steel bars, the third section of bent steel bars, the fourth section of bent steel bars and the fifth section of bent steel bars; the length of the first section of bent steel bars is , the length of the second section of bent steel bar is , the length of the third section of bent steel bar is , the length of the fourth section of bent steel bar is , the fifth section of bent steel bar , the length of the first section of the bent steel bar is the same as the length of the fifth section of the bent steel bar, the length of the second section of the bent steel bar is the same as the length of the fourth section of the bent steel bar, and the length of the first section of the bent steel bar is greater than the length of the second section of the bent steel bar, that is = > = The height of the second section of bent steel bars is determined according to the height of the cold-formed S-shaped steel. = =0.5 , the length of the third section of bent steel bar is the same as the length of each section of cold-bent S-shaped steel, that is, = .

5. The steel-concrete shear connector according to claim 3, characterized in that: The height of the cold-bent S-shaped steel is , the thickness of the cold-formed S-shaped steel is and ≥12mm; the lengths of the first section of cold-bent S-shaped steel, the second section of cold-bent S-shaped steel, the third section of cold-bent S-shaped steel, the fourth section of cold-bent S-shaped steel and the fifth section of cold-bent S-shaped steel are , the diameter of the bent steel bar , the diameter of the reserved circular hole in the first section of cold-bent S-shaped steel >The diameter of the bent steel bar ; The diameter of the semicircular hole , and the diameter of the bent steel bar same.

6. The steel-concrete shear connector according to claim 1, characterized in that: The two opening directions of the cold-bent S-shaped steel are along the longitudinal shear direction of the composite beam.

7. The steel-concrete shear connector according to claim 4, characterized in that: The first section of bent steel bars and the fifth section of bent steel bars are respectively inserted into the reserved circular holes of the first section of cold-bent S-shaped steel and the fifth section of cold-bent S-shaped steel, and the third section of bent steel bars is erected on the reserved semicircular holes of the third section of cold-bent S-shaped steel and fixedly connected.

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