Fatigue test device for polyethylene pipe

Abstract

The utility model discloses a polyethylene pipe fatigue test device which comprises a fatigue test machine, a piston power assembly and a pipe fitting clamping assembly, the fatigue test machine is provided with a test bed, and a driving piece is arranged above the test bed; the piston power assembly is arranged on the test bed, the piston power assembly comprises a barrel and a piston movably arranged in the barrel, the inner wall of the barrel is in close fit with the piston to form an inner cavity, a second medium valve is arranged on the barrel, and the piston is connected with the driving part; the pipe fitting clamping assembly is connected with the second medium valve through a medium conveying pipeline, and the pipe fitting clamping assembly is used for clamping a to-be-tested pipe fitting. The male polyethylene pipe fatigue test device can simulate the actual fatigue working condition of a pipe fitting, different atmosphere environment tests are achieved by replacing a pressure medium, and an environment box is not needed.

Description

Technical Field

[0001] This disclosure relates to the field of fatigue testing equipment technology, and in particular to a fatigue testing equipment for polyethylene pipes. Background Technology

[0002] Polyethylene (PE) is a widely used plastic pipe material in municipal engineering, construction, water conservancy, agriculture, and other fields. Due to its good corrosion resistance, low-temperature toughness, UV resistance, and ease of construction, PE pipes are widely used in water supply, drainage, gas pipelines, and farmland irrigation. However, in actual use, PE pipes may encounter cyclic loads or vibrations, especially under the influence of geological activity, climate change, or fluctuations in fluid medium pressure. In these conditions, the pipes are frequently subjected to alternating mechanical stress environments. This alternating load can lead to fatigue failure of the material, thus affecting the long-term service life and reliability of the pipes.

[0003] Currently, a complete fatigue life assessment method has been established for uniaxial fatigue testing of materials. However, in reality, the vast majority of fatigue failures, including those of polyethylene pipes, are caused by multiaxial random loads. Existing multiaxial fatigue testing equipment can only perform single or combined fatigue tests on standard specimens under tension, compression, bending, and torsion, lacking fatigue testing equipment that simulates the actual service conditions of pipe fittings. Utility Model Content

[0004] This application provides a fatigue testing device for polyethylene pipes, which solves the problem that existing fatigue testing equipment cannot simulate the actual fatigue conditions of pipe fittings.

[0005] This application provides a fatigue testing device for polyethylene pipes, comprising:

[0006] A fatigue testing machine, wherein the fatigue testing machine has a test bench and a driving component is provided above the test bench;

[0007] A piston power assembly is provided on the test bench. The piston power assembly includes a cylinder and a piston movably disposed in the cylinder. The inner wall of the cylinder is tightly fitted with the piston to form an inner cavity. A medium valve is provided on the cylinder. The piston is connected to the driving component.

[0008] A pipe clamping assembly is provided, which is connected to the medium valve 2 via a medium delivery pipeline. The pipe clamping assembly is used to clamp the pipe to be tested. The pipe clamping assembly includes a clamping cover 1 and a clamping cover 2. A medium valve 3 is provided on the clamping cover 1. Both ends of the pipe to be tested are respectively sealed to the clamping cover 1 and the clamping cover 2.

[0009] During the fatigue test, a pressure medium is introduced into the cylinder and the pipe to be tested. The drive unit of the fatigue testing machine drives the piston to reciprocate and apply load. The pressure inside the pipe to be tested is changed by the movement of the piston, and the fatigue test is carried out.

[0010] In the polyethylene pipe fatigue testing apparatus provided according to at least one embodiment of the present disclosure, a medium valve is provided on the piston.

[0011] In the polyethylene pipe fatigue testing apparatus provided according to at least one embodiment of the present disclosure, a discharge valve is provided on the clamping cover 2.

[0012] In the polyethylene pipe fatigue testing device provided according to at least one embodiment of the present disclosure, a pressure gauge is provided on the clamping cover 2.

[0013] In the polyethylene pipe fatigue testing device provided according to at least one embodiment of the present disclosure, the two ends of the pipe to be tested are respectively connected to the clamping cover one and the clamping cover two by hot-melt welding.

[0014] In the polyethylene pipe fatigue testing apparatus provided according to at least one embodiment of the present disclosure, the pressure medium includes, but is not limited to, air, water, oil, and natural gas.

[0015] One or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages:

[0016] 1. To fill the gap in actual fatigue simulation testing machines for polyethylene pipe fittings;

[0017] 2. Different atmospheric environments can be tested by changing the pressure medium, eliminating the need for an environmental chamber;

[0018] 3. The device has a simple structure, is easy to manufacture, and can be mass-produced. Attached Figure Description

[0019] Figure 1 This is a structural diagram of the polyethylene pipe fatigue testing device in the embodiments of this application;

[0020] Figure 2a This is a front view of the piston power assembly in an embodiment of this application;

[0021] Figure 2b This is a cross-sectional view of the piston power assembly in an embodiment of this application;

[0022] Figure 2c This is a top view of the piston power assembly in an embodiment of this application;

[0023] Figure 3 This is a structural diagram of the fatigue testing machine in an embodiment of this application;

[0024] Figure 4aThis is a front view of the pipe clamping assembly in an embodiment of this application;

[0025] Figure 4b This is a cross-sectional view of the pipe clamping assembly in an embodiment of this application. Detailed Implementation

[0026] This application provides a fatigue testing device for polyethylene pipes to solve the problem that existing fatigue testing equipment cannot simulate the actual fatigue conditions of pipe fittings. By changing the pressure medium, different atmospheric environments can be tested, eliminating the need for an environmental chamber. The device has a simple structure, is easy to manufacture, and can be mass-produced.

[0027] The technical solution in this application embodiment is to solve the problem of being unable to simulate the actual fatigue working conditions of pipe fittings. The overall approach is as follows:

[0028] The pipe to be tested is clamped using a pipe clamping assembly. The pipe is then connected to the piston power assembly on the fatigue testing machine via a media valve. Pressure media is input into both the pipe and the piston power assembly. Test parameters are input into the fatigue testing machine (e.g., waveform (triangular wave), displacement (±1.0mm), frequency (2Hz), etc.). Test stop parameters are set (e.g., fixed cycle time (10,000 times), sudden pressure drop (polyethylene pipe rupture), etc.). The test begins. Different atmospheric environments can be tested by changing the pressure media, eliminating the need for an environmental chamber. This allows for the simulation of actual fatigue conditions of the pipe, improving the production quality of the pipe.

[0029] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0030] Example 1

[0031] like Figure 1As shown, the polyethylene pipe fatigue testing device in this embodiment includes a fatigue testing machine 100, a piston power assembly 200, and a pipe clamping assembly 400. The fatigue testing machine 100 has a test bench, and a driving component is arranged above the test bench. The piston power assembly 200 is disposed on the test bench 110, and the piston power assembly 200 includes a cylinder 210 and a piston 220 movably disposed within the cylinder 210. The inner wall of the cylinder 210 and the piston 220 are tightly fitted to form an inner cavity. A second medium valve 240 is provided on the cylinder 210, and the piston 220 is connected to the driving component; the pipe clamping assembly 400 is connected to the second medium valve 240 through the medium conveying pipe 300, and the pipe clamping assembly 400 is used to clamp the pipe to be tested. The pipe clamping assembly 400 includes a first clamping cover 420 and a second clamping cover 430. A third medium valve 440 is provided on the first clamping cover 420, and the two ends of the pipe to be tested are respectively sealed to the first clamping cover 420 and the second clamping cover 430.

[0032] During the fatigue test, a pressure medium is input into the cylinder and the pipe to be tested. The drive component of the fatigue testing machine 100 drives the piston 220 to reciprocate and apply load. The pressure inside the pipe to be tested 410 is changed by the movement of the piston 220, and the fatigue test is carried out.

[0033] In this embodiment, the two ends of the test tube 410 are connected to the clamping cover 420 and the clamping cover 430 respectively by hot-melt welding.

[0034] like Figures 1-3 As shown, the cylinder 210 is fixed to the test bench 110 of the fatigue testing machine 100 by four positioning bolts 250 and four cylinder fixing lugs 212 on the cylinder 210, and the upper end of the piston 220 is connected to the fatigue testing machine 100.

[0035] The pressure medium described in this embodiment includes, but is not limited to, air, water, oil, and natural gas. It can be selected based on the actual working medium of the polyethylene pipe or the testing requirements. Different atmospheric environments can be tested by changing the pressure medium, eliminating the need for an environmental chamber. In this example, hydraulic oil is used as the pressure medium.

[0036] For example, the piston 220 is provided with a medium valve 230, which facilitates the input of pressure medium into the cylinder 210, improving operational convenience. Specifically, as... Figure 2b As shown, the first medium valve 230 is fixed on the piston medium hole 221 and is used to input pressure medium into the inner cavity, and the second medium valve 240 is fixed on the cylinder medium hole 211 and is used to output pressure medium into the medium conveying pipeline 300.

[0037] For example, the clamping cover 430 is provided with a discharge valve 450, which facilitates the discharge of pressure medium and pressure control within the pipe fitting 400 to be tested. Specifically, as shown... Figure 4a , 4b As shown,

[0038] The discharge valve 450 is fixed on the medium output port 431 of the pipe fitting retaining cover 2 430 and is used to release the pressure medium in the polyethylene pipe 410. The medium valve 3 440 is fixed on the medium input port 421 of the pipe fitting retaining cover 1 420 and is used to deliver the pressure medium into the polyethylene pipe 410.

[0039] Furthermore, a pressure gauge 460 is provided on the clamping cover 430 for pressure monitoring. Figure 4a , 4b As shown, the pressure gauge 460 is fixed on the pressure gauge hole 432 of the pipe fitting support cover 430 and is used to measure the pressure inside the polyethylene pipe 410.

[0040] The technical solutions described in the embodiments of this application have at least the following technical effects or advantages:

[0041] The polyethylene pipe fatigue testing device of this application can simulate the actual fatigue conditions of pipe fittings and achieve different atmospheric environment tests by changing the pressure medium, without the need for an environmental chamber.

[0042] The operation process of this embodiment is implemented as follows:

[0043] The pressure media applicable to the embodiments of this disclosure include, but are not limited to, air, water, oil, natural gas, etc., and can be selected according to the actual working medium of the polyethylene pipe or the test requirements. The pressure media selected in this example is hydraulic oil.

[0044] 1. Before the test, the equipment components should be arranged according to... Figure 1 As shown in the diagram, strain gauges are attached to the surface of the polyethylene pipe.

[0045] 2. Open medium valve 1 230, medium valve 2 240, medium valve 3 440 and discharge valve 450, and input hydraulic oil through medium valve 1 230 until hydraulic oil flows out continuously from discharge valve 450.

[0046] 3. Close the drain valve 450, continue to input hydraulic oil until the specified test pressure is reached (e.g., 0.5MPa), and close the medium valve 230.

[0047] 4. Turn on the fatigue testing machine 100, input the test parameters (e.g., waveform (triangular wave), displacement (±1.0mm), frequency (2Hz), etc.), set the test stop parameters (e.g., fixed cycle (10,000 times), pressure drop (polyethylene pipe rupture), etc.), and start the test.

[0048] 5. After the experiment, record the data.

[0049] 6. Open the drain valve to drain the hydraulic oil, and then turn off the fatigue testing machine.

[0050] It should be noted that a fatigue testing machine is a machine mainly used to determine the fatigue performance of metals and their alloys under tensile, compressive, or alternating tensile and compressive loads at room temperature. This is existing technology, and its usage is well known to those skilled in the art.

[0051] Although preferred embodiments of this disclosure have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this disclosure.

[0052] Obviously, those skilled in the art can make various modifications and variations to this disclosure without departing from the spirit and scope of this utility model. Therefore, if these modifications and variations of this disclosure fall within the scope of the claims of this disclosure and their equivalents, this disclosure is also intended to include these modifications and variations.

Claims

1. A fatigue testing device for polyethylene pipes, characterized in that, include: A fatigue testing machine, wherein the fatigue testing machine has a test bench and a driving component is provided above the test bench; A piston power assembly is provided on the test bench. The piston power assembly includes a cylinder and a piston movably disposed in the cylinder. The inner wall of the cylinder is tightly fitted with the piston to form an inner cavity. A medium valve is provided on the cylinder. The piston is connected to the driving component. A pipe clamping assembly is provided, which is connected to the medium valve 2 via a medium delivery pipeline. The pipe clamping assembly is used to clamp the pipe to be tested. The pipe clamping assembly includes a clamping cover 1 and a clamping cover 2. A medium valve 3 is provided on the clamping cover 1. Both ends of the pipe to be tested are respectively sealed to the clamping cover 1 and the clamping cover 2. During the fatigue test, a pressure medium is introduced into the cylinder and the pipe to be tested. The drive unit of the fatigue testing machine drives the piston to reciprocate and apply load. The pressure inside the pipe to be tested is changed by the movement of the piston, and the fatigue test is carried out.

2. The polyethylene pipe fatigue testing device as described in claim 1, characterized in that, The piston is equipped with a medium valve.

3. The polyethylene pipe fatigue testing apparatus as described in claim 1 or 2, characterized in that, The clamping cover is equipped with a discharge valve.

4. The polyethylene pipe fatigue testing device as described in claim 3, characterized in that, A pressure gauge is provided on the clamping cover 2.

5. The polyethylene pipe fatigue testing device as described in claim 1, characterized in that, The two ends of the pipe fitting to be tested are connected to clamping cover one and clamping cover two respectively by hot melt welding.

6. The polyethylene pipe fatigue testing apparatus as described in claim 1, characterized in that, The pressure medium includes, but is not limited to, air, water, oil, and natural gas.

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