Force transfer test device for parallel steel wires of main cable under action of circumferential pressure

Abstract

The utility model discloses a main cable parallel steel wire force transmission test device under the action of circumferential pressure, which comprises a half cable clamp body and a support column, a fixing lug is arranged on the half cable clamp body, a screw hole corresponding to the top of the support column is arranged on the fixing lug, the half cable clamp body and the support column are fastened through a bolt and a nut, and a gap is reserved between the half cable clamp body and the support column; a cross-core pressure sensor is mounted between the nut and the fixing lug; a horizontal bearing platform is welded in the middle of the supporting column, a plurality of test steel wires are stacked in the half cable clamp body, a bottom pressure sensor is arranged between the test steel wires and the horizontal bearing platform, and the bottom pressure sensor and a cross-core pressure sensor form a strain data acquisition system. The device accurately simulates and feeds back the internal force transmission of the parallel steel wires under the circumferential pressure in real time, realizes the visual test of the complex force transmission between the internal steel wires of the main cable under the action of the circumferential force of the cable clamp and the like, and can provide necessary support for the force transmission analysis of the parallel steel wires of the main cable, the design of the bridge cable clamp and the anti-slip safety evaluation.

Description

Technical Field

[0001] The utility model belongs to the technical field of bridge engineering, and particularly relates to a test device for the force transmission of parallel wires of a main cable under circumferential pressure. Background Technique

[0002] The suspension bridge is the bridge type with the largest spanning capacity, and the main cable composed of parallel high-strength wires is used as the main load-bearing member. The main cable runs through each span, and the sling is connected by a cable clamp in the span to bear the deck load. Therefore, the reliable connection performance between the main cable and the cable clamp is directly related to the safety of the whole bridge structure system. In terms of the essential mechanical mechanism, the main cable wires in the cable clamp area are under the circumferential force of the cable clamp, and thus the internal wires are compressed and generate frictional force to prevent slipping with the cable clamp. Therefore, it is very important to accurately master the internal force transmission mechanism of the main cable wires under the circumferential force.

[0003] The main cable is composed of thousands of discrete parallel wires, and there are a large number of voids when viewed from the cross-section. Under the circumferential tightening pressure of the rigid cable clamp body, the discrete parallel wires not only undergo elastic deformation, but also move relative to each other in position and are compacted by extrusion. These factors make it extremely difficult to establish an analytical theoretical model for the pressure transmission mode and distribution of the internal wires of the main cable. Although the finite element method can establish a contact analysis model between a small number of wires, it is obviously not enough to reveal the distribution law of the internal wires of the main cable of the suspension bridge. Due to the huge number of wires and the strong nonlinearity of the contact problem, the finite element model is prone to non-convergence problems, and the existing computer performance cannot meet the solution requirements. Therefore, it is the most realistic and reliable choice to test the internal pressure of the parallel wires of the main cable under the circumferential tightening pressure of the cable clamp by experimental means. However, no ready-made scheme can be used for reference at present.

[0004] The patent (application publication number CN117634160A) provides a detailed calculation method to determine the mechanical properties of the semi-parallel wires of the stay cable. Through a variety of mathematical models and calculation steps, the influence of the circumferential pressure on the mechanical properties of the wires can be evaluated in detail. However, the complexity of the method and the dependence on the assumed conditions may have certain limitations in practical applications, and there is a lack of experimental verification. Compared with the actual experiment, although the theoretical model can provide detailed calculation results, it is not as intuitive and reliable as the experimental data. Content of the Utility Model

[0005] In order to clarify the force transmission form of the parallel wires of the main cable under the circumferential pressure, the utility model provides a test device for the force transmission of the parallel wires of the main cable under the circumferential pressure.

[0006] A test device for the force transmission of parallel wires in the main cable under circumferential pressure of the utility model includes a semi-cable clip body and a support column. A fixed ear is provided on the semi-cable clip body, and a screw hole is opened on the fixed ear corresponding to the top of the support column. The semi-cable clip body and the support column are fastened by bolts and nuts, and a gap is reserved between them; a through-hole type pressure sensor is installed between the nut and the fixed ear.

[0007] A horizontal bearing platform is welded in the middle of the support column, and a number of test wires are stacked inside the semi-cable clip body. A bottom pressure sensor is arranged between the test wires and the horizontal bearing platform. The bottom pressure sensor and the through-hole type pressure sensor form a strain data acquisition system.

[0008] Furthermore, a digital image acquisition system is also provided, including an optical camera fixed on a bracket on one side of the test wires, and the optical camera is connected to an image acquisition and analysis system.

[0009] Furthermore, the test wires include test steel wires and fine steel wires. Among them, the length of the test steel wires is less than the length of the semi-cable clip body and is placed inside, and the fine steel wires are used to fill the gaps between the test steel wires and the semi-cable clip body.

[0010] Furthermore, one bottom pressure sensor is arranged for every three steel wires at the bottom of the test steel wires.

[0011] Furthermore, the selected range of the wire diameter of the test steel wires is 5-7 mm; the selected range of the wire diameter of the fine steel wires is 1-3 mm.

[0012] The beneficial technical effects of the utility model are as follows:

[0013] The utility model uses a semi-anatomical model to accurately simulate and real-time feedback the force transmission inside the parallel wires under circumferential pressure, realizing an intuitive test for the complex force transmission between the internal steel wires of the main cable under the action of circumferential force such as cable clips, and can provide necessary support for the force transmission analysis of the parallel wires of the main cable and the design and anti-slip safety assessment of bridge cable clips. Therefore, the utility model has important value in both scientific research and engineering applications. Description of the Drawings

[0014] Figure 1 It is a schematic structural diagram of a test device for the force transmission of parallel wires in the main cable under circumferential pressure of the utility model.

[0015] Figure 2 It is a left view of a test device for the force transmission of parallel wires in the main cable under circumferential pressure of the utility model.

[0016] Figure 3 It is a top view of a test device for the force transmission of parallel wires in the main cable under circumferential pressure of the utility model.

[0017] Figure 4This is a test schematic diagram of the test device for the force transmission of parallel wires in the main cable under circumferential pressure of the utility model.

[0018] In the figure: 1 - half cable clamp body, 2 - bolt, 3 - nut, 4 - through-hole pressure sensor, 5 - test wire, 6 - thin wire, 7 - support column, 8 - bottom pressure sensor, 9 - horizontal bearing platform, 10 - optical camera, 11 - image acquisition and analysis system, 12 - fixed ear. Specific implementation mode

[0019] The following further elaborates on the utility model in conjunction with the attached drawings and specific implementation methods.

[0020] A test device for the force transmission of parallel wires in the main cable under circumferential pressure of the utility model is as Figure 1 shown, including a half cable clamp body 1 and a support column 7. A fixed ear 12 is arranged on the half cable clamp body 1, and a screw hole is opened on the fixed ear 12 corresponding to the top of the support column 7. As Figure 2 shown, the half cable clamp body 1 and the support column 7 are fastened through a bolt 2 and a nut 3, and a gap is reserved between the two. As Figure 3 shown, a through-hole pressure sensor 4 is installed between the nut 3 and the fixed ear 12.

[0021] A horizontal bearing platform 9 is welded in the middle of the support column 7. A number of test wires are stacked inside the half cable clamp body 1. A bottom pressure sensor 8 is arranged between the test wires and the horizontal bearing platform 9. The bottom pressure sensor 8 and the through-hole pressure sensor 4 constitute a strain data acquisition system.

[0022] Furthermore, as Figure 4 shown, a digital image acquisition system is also provided, including an optical camera 10 fixed on a bracket on one side of the test wire. The optical camera 10 is connected to the image acquisition and analysis system 11. During digital image acquisition, white paint is first sprayed on the surface of the test wire, and then black paint is sprayed to form speckles. The image of the exposed surface of the wire is collected by the optical camera 10 fixed on the bracket.

[0023] Furthermore, the test wire includes a test wire 5 and a thin wire 6. Among them, the length of the test wire 5 is less than the length of the half cable clamp body 1 and is placed inside. The thin wire 6 is used to fill the gap between the test wire 5 and the half cable clamp body 1 to achieve uniform force transmission.

[0024] Furthermore, as Figure 1 shown, one bottom pressure sensor 8 is arranged for every three wires at the bottom of the test wire 5.

[0025] Furthermore, the selected range of the wire diameter of the test wire 5 is 5 - 7 mm to evaluate the influence of the wire diameter on the force transmission. The selected range of the wire diameter of the thin wire 6 is 1 - 3 mm to facilitate uniform filling of the gap.

[0026] The test method of this utility model is as follows:

[0027] S1: Arrange bottom pressure sensors on the horizontal platform and stack steel wires on it.

[0028] S2: Fix the half cable clamp body and the support column with bolts and nuts, ensure an appropriate gap is left, and add fine steel wires to ensure uniform force transmission between the steel wires.

[0029] S3: Install a through-type pressure sensor between the nut and the fixed ear, and place bottom pressure sensors between every three steel wires between the test steel wires and the horizontal platform; Set an optical camera to align with the test steel wires and connect the image acquisition and analysis system.

[0030] S4: Gradually increase the tightening force of the nut and record the strain data and image information corresponding to each level of loading.

[0031] S5: Unscrew the nut, release the tightening force, and take out the test steel wires.

[0032] S6: Repeat steps S1 to S5 to conduct tests with different wire diameters.

[0033] It should be noted that for those skilled in the art, it is obvious that this utility model is not limited to the above details, and without departing from the spirit or basic characteristics of this utility model, this invention can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of this utility model is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in this utility model, and any reference signs in the claims should not be regarded as limiting the claims involved.

[0034] In this utility model, the principle and implementation method of this utility model are elaborated. The above description is only used to help understand the method and its core idea of this utility model; At the same time, for those of ordinary skill in the art, according to the idea of this utility model, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be construed as a limitation to this utility model.

Claims

1. A test device for the force transmission of parallel wires of a main cable under circumferential pressure, characterized in that It includes a semi-cable clamp body (1) and a support column (7). A fixing ear (12) is provided on the semi-cable clamp body (1). A screw hole is opened on the fixing ear (12) corresponding to the top of the support column (7). The semi-cable clamp body (1) and the support column (7) are fastened by a bolt (2) and a nut (3), and a gap is reserved between them; a through-hole type pressure sensor (4) is installed between the nut (3) and the fixing ear (12). A horizontal bearing platform (9) is welded in the middle of the support column (7). A number of test steel wires are stacked inside the semi-cable clamp body (1). A bottom pressure sensor (8) is arranged between the test steel wires and the horizontal bearing platform (9). The bottom pressure sensor (8) and the through-hole type pressure sensor (4) constitute a strain data acquisition system.

2. The circumferential pressure acting on the main cable parallel wire force transmission test device according to claim 1, characterized in that A digital image acquisition system is also provided, including an optical camera (10) fixed on a bracket on one side of the test steel wires. The optical camera (10) is connected to an image acquisition and analysis system (11).

3. The circumferential pressure acting on the main cable parallel wire force transmission test device according to claim 1, characterized in that, The test steel wires include test steel wires (5) and fine steel wires (6). The length of the test steel wires (5) is less than the length of the semi-cable clamp body (1) and is placed inside. The fine steel wires (6) are used to fill the gap between the test steel wires (5) and the semi-cable clamp body (1).

4. A circumferential pressure acting on the main cable parallel wire force transmission test device according to claim 3, characterized in that, One bottom pressure sensor (8) is arranged for every three steel wires at the bottom of the test steel wires (5).

5. The circumferential pressure - acting main cable parallel wire force - transmission test device according to claim 3, characterized in that, The wire diameter of the test steel wires (5) is selected in the range of 5 - 7 mm; the wire diameter of the fine steel wires (6) is selected in the range of 1 - 3 mm.

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