A bending moment test fixture for insulating joints

Abstract

This utility model discloses a bending moment testing fixture for an insulating joint, comprising a bottom support assembly and a top pressure head assembly. The bottom support assembly and the top pressure head assembly are in line contact or surface contact with the bottom and top sides of the insulating joint, respectively. The two force-bearing points of the top pressure head assembly and the two support points of the bottom support assembly are centrally symmetrically distributed on the axial cross-section of the insulating joint, forming a four-point bending loading structure to apply a pure bending moment load to the insulating joint. This utility model, through the design of the four-point bending loading structure formed by the top pressure head assembly and the bottom support assembly, can apply a pure bending moment load to the insulating joint, highly replicating the bending stress state of the insulating joint under actual working conditions such as soil settlement and ground load in a buried environment. The test results can truly and accurately reflect the bending resistance and sealing reliability of the insulating joint, greatly improving the reliability of the test data.

Description

Technical Field

[0001] This utility model relates to the field of pipeline component testing equipment, specifically to a bending moment testing fixture for insulating joints. Background Technology

[0002] Insulating joints are a special type of joint used in buried gas and oil pipelines. Their function is to block the current in the pipeline while transporting the medium, thereby achieving electrochemical corrosion prevention (cathode protection).

[0003] Insulating joints have high insulation resistance, high breakdown voltage, good mechanical properties, can be directly buried underground, require no maintenance, and have a long service life.

[0004] The hydrostatic bending moment test of an insulating joint is a key test to verify its structural performance under the combined action of pressure and bending moment. Its main purpose is to ensure the sealing performance and structural stability of the joint under complex working conditions (such as the pressure deformation of buried pipelines).

[0005] However, existing technologies have obvious drawbacks: Inadequate standards and specifications: Current standards (such as GB 50028-2006) do not provide detailed regulations on the specific methods and parameters for water pressure bending moment tests, leading to arbitrary practices and a lack of uniformity in actual operation.

[0006] Lagging testing technology: Conventional hydrostatic tests only focus on static sealing performance and cannot effectively simulate and test fatigue performance under dynamic bending moment.

[0007] The existing tooling design is unreasonable: it generally adopts a top single-point pressure method, which concentrates the stress point. This is very different from the uniform load condition of the insulating joint in the buried environment. It is easy to cause the specimen to fail prematurely due to non-actual load (such as stress concentration), and it cannot truly reflect its bending performance.

[0008] Therefore, there is an urgent need for a bending moment testing fixture for insulating joints that can simulate the actual buried stress state, is easy to operate, and provides reliable results. Utility Model Content

[0009] This invention provides a bending moment testing fixture for insulating joints, which can solve the above-mentioned shortcomings of existing bending moment testing fixtures for insulating joints.

[0010] To solve the above-mentioned technical problems, this utility model provides a bending moment testing fixture for insulating joints, comprising: A bottom support assembly for supporting the insulating connector to be tested, wherein the bottom support assembly is in line contact or surface contact with the bottom two sides of the insulating connector; The top pressure head assembly is disposed above the insulating joint and is used to receive the downward pressure of the press. The top pressure head assembly is in line contact or surface contact with the two sides of the top of the insulating joint. The two force-bearing points of the top pressure head assembly and the two support points of the bottom support assembly are centrally symmetrically distributed on the axial section of the insulating joint, forming a four-point bending loading structure to apply a pure bending moment load to the insulating joint.

[0011] In a preferred embodiment of the present invention, the bottom support assembly includes two independent and symmetrically arranged bottom supports. Each bottom support includes a base and a support block vertically fixed thereon. The top end of the support block forms a support point that contacts the insulating joint.

[0012] In a preferred embodiment of the present invention, the top end of the support block is provided with a V-shaped groove or an arc-shaped groove.

[0013] In a preferred embodiment of the present invention, the top pressure head assembly includes a crossbeam and two pressure arms symmetrically connected to the bottom of the crossbeam, the bottom end of the pressure arms forming a force-bearing point that contacts the insulating joint.

[0014] In a preferred embodiment of this utility model, the crossbeam is made of channel steel and has reinforcing ribs welded inside.

[0015] In a preferred embodiment of the present invention, the bottom end of the pressure arm is provided with a V-shaped protrusion or an arc-shaped protrusion.

[0016] In a preferred embodiment of the present invention, a removable wear-resistant pad is provided on the contact surface between the top pressure head assembly and / or the bottom support assembly and the insulating joint.

[0017] The beneficial effects of this utility model are as follows: This utility model provides a bending moment testing fixture for insulating joints. Through the design of a four-point bending loading structure consisting of a top pressure head assembly and a bottom support assembly, it can apply a pure bending moment load to the insulating joint. This highly replicates the bending stress state that the insulating joint bears under actual working conditions such as soil settlement and ground load in the buried environment. The test results can truly and accurately reflect the bending resistance and sealing reliability of the insulating joint, greatly improving the reliability of the test data. It is easy to operate and highly practical. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of an insulating joint bending moment testing fixture of this utility model in a water pressure bending moment test; Figure 2 This is a front view structural diagram of the bottom support of this utility model; Figure 3 yes Figure 2 A schematic diagram of the side view structure; Figure 4 This is a front view structural diagram of the top pressure head assembly of this utility model; Figure 5 yes Figure 4 A schematic diagram of the side view structure; Figure 6 This is a schematic diagram of the forces acting on the insulating joint of this utility model; The component names in the attached diagram are: 100. Insulating connector; 200. Press workbench; 10. Bottom support; 11. Base; 12. Support block; 20. Crossbeam; 21. Channel steel; 22. Reinforcing rib; 23. Pressure transmission point; 30. Press arm. Detailed Implementation

[0019] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the scope of protection of the present invention.

[0020] Example 1 Combination Figure 1-6 As shown in the figure, this embodiment provides a bending moment test fixture for an insulating joint, which mainly includes a bottom support assembly and a top pressure head assembly.

[0021] The bottom support assembly is located on the press workbench 200 and is used to support the insulating connector 100 to be tested. The bottom support assembly is in line contact or surface contact with the bottom sides of the insulating connector 100.

[0022] Specifically, the bottom support assembly includes two independent and symmetrically arranged bottom supports 10. Each bottom support 10 includes a base 11 and a support block 12 vertically fixed thereon. The top of the support block 12 is provided with a V-shaped groove, which forms a support point that contacts the outer wall of the insulating joint 100 tube. Furthermore, the groove may also be an arc-shaped groove or other shapes that can adapt to the tubular specimen.

[0023] The top pressure head assembly is disposed above the insulating joint 100 and is used to receive the downward pressure of the press. The top pressure head assembly is in line contact or surface contact with the two sides of the top of the insulating joint 100.

[0024] Specifically, the top pressure head assembly includes a crossbeam 20 and two pressure arms 30 symmetrically connected to the bottom of the crossbeam 20.

[0025] The crossbeam 20 is made of channel steel 21, and has internal reinforcing ribs 22 welded to it to enhance its structural rigidity and prevent excessive deformation under stress. The pressure transmission point 23 of the press is located in the central area of ​​the top surface of the crossbeam 20.

[0026] The bottom end of the pressure arm 30 is provided with a V-shaped protrusion, which is V-shaped in this embodiment. The end of the V-shaped protrusion forms a force-bearing point that contacts the insulating joint 100. Furthermore, the protrusion may also be an arc-shaped protrusion.

[0027] Specifically, the two force-bearing points of the top pressure head assembly and the two support points of the bottom support assembly are centrally symmetrically distributed on the axial section of the insulating joint 100, together forming a standard four-point bending loading structure to apply a pure bending moment load to the insulating joint 100.

[0028] Furthermore, in order to reduce wear at the contact points and prevent slippage, a removable wear-resistant pad (not shown in the figure) is provided on the V-shaped protrusion at the bottom end of the pressure arm 30 and / or in the V-shaped groove of the support block 12, for example, by means of bolt connection or inlay.

[0029] The working principle of the insulating joint bending moment testing fixture of this utility model is as follows: First, place the insulating connector 100 horizontally on the two support points (i.e., the two V-shaped grooves) of the bottom support assembly.

[0030] Then, the top pressure head assembly is placed above the insulating joint 100, so that the V-shaped protrusions at the bottom of its two pressure arms 30 contact the corresponding positions on the top of the insulating joint 100.

[0031] Subsequently, the press is driven so that its pressure transmission point 23 applies a vertically downward pressure F to the center of the crossbeam 20. In this embodiment, a small press with an oil pump gauge pressure of 0.5 MPa is used, and the applied pressure F is 35.7 kN. This pressure is transmitted through the crossbeam 20 and the pressure arm 30, and together with the reaction force of the bottom support assembly, they form a force couple, thereby applying a pure bending moment load to the insulating joint 100 through the four-point bending loading structure, perfectly simulating the bending conditions experienced by buried pipelines.

[0032] This invention, through the above-mentioned four-point stress structure design, simulates the buried environment and successfully converts the single concentrated load of the press into a pure bending moment load simulating the real working condition. It overcomes the stress concentration problem caused by single-point pressurization in the prior art, makes the specimen uniformly stressed, and the test results accurate and reliable, effectively avoiding the specimen from being damaged by non-actual loads.

[0033] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the description and drawings of this utility model, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A fixture for testing the bending moment of an insulating joint, characterized in that, include: A bottom support assembly for supporting the insulating connector to be tested, wherein the bottom support assembly is in line contact or surface contact with the bottom two sides of the insulating connector; The top pressure head assembly is disposed above the insulating joint and is used to receive the downward pressure of the press. The top pressure head assembly is in line contact or surface contact with the two sides of the top of the insulating joint. The two force-bearing points of the top pressure head assembly and the two support points of the bottom support assembly are centrally symmetrically distributed on the axial section of the insulating joint, forming a four-point bending loading structure to apply a pure bending moment load to the insulating joint.

2. The tooling according to claim 1, characterized in that, The bottom support assembly includes two independent and symmetrically arranged bottom supports. Each bottom support includes a base and a support block vertically fixed thereon. The top of the support block forms a support point that contacts the insulating joint.

3. The tooling according to claim 2, characterized in that, The top of the support block is provided with a V-shaped groove or an arc-shaped groove.

4. The tooling according to claim 1, characterized in that, The top pressure head assembly includes a crossbeam and two pressure arms symmetrically connected to the bottom of the crossbeam, the bottom ends of the pressure arms forming a force-bearing point that contacts the insulating joint.

5. The tooling according to claim 4, characterized in that, The crossbeam is made of channel steel and has reinforcing ribs welded inside.

6. The tooling according to claim 4 or 5, characterized in that, The bottom end of the pressure arm is provided with a V-shaped protrusion or an arc-shaped protrusion.

7. The tooling according to claim 1, characterized in that, The contact surfaces of the top pressure head assembly and / or bottom support assembly with the insulating joint are provided with removable wear-resistant pads.

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