Modularized rubber stress relaxation testing device and testing method

Abstract

The invention relates to the technical field of material mechanical property testing, in particular to a modularized rubber stress relaxation testing device and method.The modularized rubber stress relaxation testing device comprises a base, a stretching assembly, a compression assembly and a force sensor, and the stretching assembly and the base are detachably connected to form a stretching testing module; according to the invention, the common base and the detachable and replaceable stretching assembly and compression assembly are adopted, so that the same set of device can be flexibly assembled into a stretching test module or a compression test module according to test requirements, and therefore, the test efficiency is improved, and the test cost is reduced. Compared with the prior art that special equipment needs to be prepared for different test modes respectively, the universality and the use flexibility of the device are improved, and the scientific research and test cost is effectively reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of material mechanical property testing, and in particular to a modular rubber stress relaxation testing device and a testing method. Background Art

[0002] Rubber is a key material for components such as tires, seals, cushions, and cables. These components are essential components of engineering structures and play a vital role in their reliability and safety. However, exposure to thermal oxidative environments and long-term use inevitably lead to chemical reactions with oxygen, causing aging and a decrease in mechanical properties. Stress relaxation is an important indicator for characterizing the effects of thermal oxidative aging. At high temperatures, it can indicate the fracture process of the rubber molecular chain network caused by thermal oxidative aging. At the same time, permanent deformation occurs when the rubber material returns to its natural state after thermal oxidative aging at a given strain rate. This phenomenon can explain the net effect of the fracture process and crosslinking process of the molecular chain network. Therefore, accurately measuring the stress relaxation of rubber materials at high temperatures is beneficial for exploring the relationship between the macroscopic mechanical behavior of rubber materials and the molecular chain network under the influence of thermal oxidative aging.

[0003] "Rubber vulcanized or thermoplastic rubber - Determination of compressive stress relaxation at room temperature and elevated temperature" (GB / T1685-2008) and "Rubber vulcanized or thermoplastic rubber - Determination of aging properties - Tensile stress relaxation test" (GB / T9871-2008) respectively specify the technical requirements for the relaxation device, force measurement device, temperature chamber, specimens, etc. for compressive stress relaxation and tensile stress relaxation of rubber materials, but lack detailed design technical content.

[0004] "Rubber, vulcanized or thermoplastic — Determination of compression set — Part 1: At ambient and elevated temperatures" (GB / T77759.1-2015) provides a detailed description of compression fixtures, but the resulting device cannot produce stress relaxation data for rubber specimens. "Rubber, vulcanized or thermoplastic — Determination of tensile set at constant elongation and tensile set, elongation, and creep under constant tensile load" (GB / T1685-2008) describes a tensile device, but only produces data on permanent set and creep.

[0005] Since rubber materials are subjected to tension, compression, and shear loads simultaneously during actual use (shear load can be replaced by plane tension), and scientific research related to thermal oxidative aging often requires testing multiple groups of specimens to ensure the reliability and regularity of the test results.

[0006] At present, there is an urgent need for a simple, small-sized stress relaxation testing device that can realize compression and tension loading modes to characterize the thermal oxidative aging mechanical behavior of rubber materials. Summary of the Invention

[0007] The present invention aims to solve the problems that stress relaxation testing devices in the prior art have a single function and are difficult to meet the requirements of both tensile and compression test modes at the same time, and that some devices have complex structures and are not convenient for large-scale parallel testing. The purpose is to provide a modular rubber stress relaxation testing device and testing method. The modular testing device can be used for both tensile stress relaxation and compressive stress relaxation monitoring, and can be placed in a temperature chamber for large-scale use. It realizes online monitoring and evaluation of the impact of thermal oxidative aging on the mechanical behavior of rubber, accelerates the development of constitutive models for thermal oxidative aging of rubber materials, and improves the reliability of rubber materials used in engineering.

[0008] The present invention is achieved through the following technical solutions: A modular rubber stress relaxation testing device comprising: base; a tensile assembly detachably connected to the base to form a tensile testing module, the tensile assembly comprising: a tensile fixture for clamping a tensile specimen and a tensile connecting rod, the tensile connecting rod being provided with a plurality of positioning portions, the positioning portions being used to fix the spacing between the tensile fixtures to set the tensile deformation of the tensile specimen; A compression assembly, which is detachably connected to the base to form a compression test module, the compression assembly comprising: a compression fixture for applying a load to the compression specimen and a limit block, the limit block being disposed between the compression fixture and the base, the limit block being used to limit the position of the compression surface of the compression fixture relative to the base to set the compression deformation of the compression specimen; A force sensor is used to measure tensile force when constituting a tensile test module, or is used to measure compressive force when constituting a compressive test module.

[0009] Furthermore, it also includes an insulation box and a data recording device, the tensile test module or the compression test module is arranged in the insulation box; the data recording device is arranged outside the insulation box and is electrically connected to the force sensor.

[0010] Optionally, the tensile clamp includes: a fixed clamp and a movable clamp, the fixed clamp is detachably connected to the base and / or the lower end of the tensile connecting rod, and clamps the lower end of the tensile specimen, the movable clamp is connected to the tensile connecting rod through a positioning portion, and clamps the upper end of the tensile specimen, and the force sensor is a tensile force sensor and is connected to the movable clamp.

[0011] Optionally, the fixing fixture is provided with a threaded hole therethrough, the base is provided with a threaded blind hole, the lower end of the tensile connecting rod is provided with an external thread, and the fixing fixture is detachably connected to the base via the tensile connecting rod passing through the threaded hole and then connected to the threaded blind hole; The positioning portion is a plurality of positioning holes axially arranged on the stretch connecting rod, the movable fixture is provided with connecting holes adapted to the positioning holes, and the movable fixture is connected via positioning pins passing through the positioning holes and the connecting holes.

[0012] Optionally, the fixing fixture includes a first lower clamping block and a second lower clamping block, and the lower end of the tensile specimen is clamped between the first lower clamping block and the second lower clamping block; The movable fixture comprises a first upper clamping block and a second upper clamping block, and the upper end of the tensile specimen is clamped between the first upper clamping block and the second upper clamping block; The first lower clamping block and the second lower clamping block, and the first upper clamping block and the second upper clamping block are all connected by clamping bolts and clamping nuts.

[0013] Optionally, the number of the clamping bolts and clamping nuts is at least three, and they are respectively located at three different positions of the tensile specimen.

[0014] Optionally, the compression fixture comprises: a compression plate, an upper plate and a compression connecting rod, wherein the compression connecting rod is used to connect the upper plate to the base; the compression specimen is placed on the base and below the compression plate; The force sensor is a pressure sensor and is disposed between the compression plate and the upper plate, and is used to transmit the load of the upper plate to the compression plate; The limit blocks are a group of limit blocks with different heights, and are used to set different compression deformation amounts by selecting limit blocks of different heights.

[0015] Optionally, a threaded blind hole is provided on the base, and the lower section of the compression connecting rod is provided with a lower section thread adapted to the threaded blind hole; The upper plate is provided with a through hole corresponding to the compression connecting rod, the upper section of the compression connecting rod is provided with an upper thread, and the upper section of the compression connecting rod passes through the through hole and is limited by a compression nut.

[0016] A testing method for a modular rubber stress relaxation testing device is provided, based on the modular rubber stress relaxation testing device described above, wherein the testing method includes a tensile relaxation stress testing method, comprising the following steps: Clamp both ends of the tensile specimen between the fixed fixture and the movable fixture respectively; Insert the positioning pin into the selected positioning hole on the tensile connecting rod to fix the position of the mobile fixture and set the tensile deformation of the tensile specimen; Place the tensile test module with set tensile deformation in the thermal insulation box; Connecting a tensile force sensor to the data recording device to record the initial tensile force and the change in tensile stress value over time at a preset temperature; The ratio of the tensile stress value to the initial tensile force was calculated to obtain the tensile stress relaxation curve.

[0017] Further, the test method includes a compression relaxation stress test method, comprising the following steps: The compression specimen is placed on the base, and a stop block of a specific height is selected from a group of stop blocks with different heights and placed on the base; Assemble the compression plate, pressure sensor and upper plate on top of the compression specimen in sequence; By tightening the compression nut used to limit the compression connecting rod, the compression plate is pressed down until it is supported by the limit block, thereby setting the compression deformation of the compression specimen; Place the compression test module with set compression deformation in the thermal insulation box; Connect the pressure sensor to a data recording device to record the initial compression force and the change in compression stress value over time at a preset temperature; The ratio of the compressive stress value to the initial compressive force is calculated to obtain the compressive stress relaxation curve.

[0018] Compared with the prior art, the present invention has the following advantages and beneficial effects: The present invention uses a common base and detachable and replaceable tensile and compression components, so that the same set of equipment can be flexibly assembled into two test modules, tensile or compression, according to test requirements. Therefore, compared with the existing technology that requires special equipment to be prepared for different test modes, the present invention improves the versatility and flexibility of the device and effectively reduces scientific research and testing costs.

[0019] The overall structure of the device of the present invention is compact. After assembly, each component forms an independent test module. Multiple test modules can be placed in the same insulation box in large quantities for long-term thermal oxygen aging and stress relaxation testing. This not only greatly improves test efficiency, but also ensures that the environmental conditions experienced by all samples are completely consistent, providing a guarantee for obtaining highly reliable experimental data and strongly supporting the research on material aging mechanisms. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings illustrate exemplary embodiments of the present invention and, together with the description thereof, are used to explain the principles of the present invention. These drawings are included to provide a further understanding of the present invention, and the accompanying drawings are included in and constitute a part of this specification and do not constitute a limitation of the embodiments of the present invention.

[0021] Figure 1 It is a structural schematic diagram of a modular rubber stress relaxation testing device according to the present invention.

[0022] Figure 2 2 is a schematic structural diagram of the tensile testing module according to the present invention.

[0023] Figure 3 is an exploded view of the tensile testing module according to the present invention.

[0024] Figure 4 2 is a schematic structural diagram of a compression test module according to the present invention.

[0025] Figure 5 is an exploded view of the compression test module according to the present invention.

[0026] Figure markings: 1-base; 2-data recording device; 3-tension sensor; 4-first lower clamping block; 5-second lower clamping block; 6-first upper clamping block; 7-second upper clamping block; 8-tension connecting rod; 9-tension specimen; 10-locating pin; 11-clamping bolt; 12-clamping nut; 13-compression nut; 14-gasket; 15-pressure sensor; 16-limiting block; 17-compression connecting rod; 18-upper plate; 19-compression plate; 20-compression specimen; 21-insulation box. DETAILED DESCRIPTION

[0027] To make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the relevant content and are not intended to limit the present invention.

[0028] It should also be noted that, for the convenience of description, only the parts related to the present invention are shown in the drawings.

[0029] In the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0030] Example 1 like Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5As shown, this embodiment discloses a modular rubber stress relaxation testing device and a complete testing system thereof. The design concept is to build a platform with high versatility and flexibility, which can adapt to two completely different mechanical testing modes by replacing different functional components.

[0031] The overall operational process involves selecting the appropriate components based on the experimental objective (tension or compression) and assembling them with a universal base 1 to create a dedicated test module. The module's unique mechanical limiter mechanism then sets and locks a precise strain. Finally, the module is placed in a temperature-controlled environment, where sensors and data logging equipment monitor the entire stress relaxation process.

[0032] Below, the key steps and composition of the technical solution are interpreted in detail. The test device includes: a base 1, a tensile component, a compression component and a force sensor.

[0033] The base 1 is a universal platform. Based on the base 1 , two modes can be configured: a tensile test mode and a compression test mode.

[0034] When a tensile test is required, the tensile assembly is detachably connected to the base 1 to form a tensile test module. The tensile assembly includes a tensile clamp for clamping a tensile specimen 9 and a tensile connecting rod 8 .

[0035] When a compression test is required, the compression assembly is detachably connected to the base 1 to form a compression test module. The compression assembly includes: a compression fixture for applying a load to the compression specimen 20 and a limit block 16 .

[0036] In addition, a key point of this scheme is to achieve constant strain of the specimen through physical limitation.

[0037] In the tensile mode, this is achieved by means of a plurality of positioning parts on the tensile connecting rod 8, which are used to fix the spacing of the tensile clamps to set the tensile deformation of the tensile specimen 9; the distance between the tensile clamps is precisely defined and locked by physical limits, thereby applying a known and constant tensile deformation.

[0038] In compression mode, a stopper 16 is positioned between the compression fixture and base 1. This stopper 16 defines the position of the compression fixture's compression surface relative to base 1, thereby setting the compression deformation of the compression specimen 20. During compression, when the compression surface of the compression fixture contacts this stopper 16, it cannot move further downward. Therefore, the height of the stopper 16 directly determines the final height of the compressed specimen, thereby setting a precise and constant compression deformation.

[0039] Force sensors are used to measure tensile force when forming a tensile test module, or to measure compressive force when forming a compression test module. Generally, force sensors are integrated into the force transmission path of the test module to sense changes in stress inside the specimen in real time.

[0040] The assembled test module is placed in an insulated box 21 to simulate the material's high-temperature operating conditions. Therefore, the tensile or compression test module is located inside the insulated box 21. The data recording device 2 is located outside the insulated box 21 and is electrically connected to the force sensor, continuously receiving and storing the mechanical data measured by the sensor.

[0041] In summary, the working principle of this embodiment is: a test module with specific functions is constructed through a modular combination of a replaceable tensile component or compression component and the universal base 1.

[0042] The procedure involves: first, selecting and assembling the appropriate test module based on the test requirements; second, using discrete positioning features on the tensile connecting rod 8 or a stopper 16 of a specific height to precisely set and lock the specimen's constant deformation through physical positioning; finally, placing the module in an insulated chamber 21, and using a force sensor and data recording device 2 to monitor and record the entire stress decay process of the specimen under constant strain and a specific temperature. This modular structure and precise physical positioning achieve a dual-purpose, simple, and reliable stress relaxation test.

[0043] By installing multiple test modules, it is possible to conduct large-scale tests on the stress relaxation and permanent deformation of rubber aged at high temperatures for different periods of time, while ensuring the number of repeatable tests and improving testing efficiency. This facilitates the exploration of the effects of thermo-oxidative aging on the mechanical behavior of rubber and the molecular chain network fracture process, as well as the relationship between stress relaxation and permanent deformation caused by thermo-oxidative aging, providing an experimental basis for constitutive modeling of rubber under the influence of thermo-oxidative aging.

[0044] The testing device can also be used for the test of the elastomer of similar rubber material, for example hydrogel and plastics.In addition the base 1 of the testing device, the tensile fixture, the compression plate 19, the connecting rod, the profile of the stop block 16 can all be changed.

[0045] Example 2 like Figure 2 and Figure 3 As shown, this embodiment focuses on the specific structure of the tensile testing module, and elaborates on the construction and connection method of its internal components and the complete mechanical process for achieving precise strain setting.

[0046] The tensile fixture includes: a fixed fixture and a movable fixture.

[0047] The fixing fixture is the reference part of the device, located at the bottom, and is detachably connected to the lower end of the base 1 and / or the tensile connecting rod 8, and clamps the lower end of the tensile specimen 9. The mobile fixture serves as the loading part of the device, is located at the top, is connected to the tensile connecting rod 8 through the positioning part, and clamps the upper end of the tensile specimen 9.

[0048] The force sensor is a tension sensor 3 and is connected to the mobile fixture. The sensor directly measures the real-time reaction force acting on the upper end of the sample due to the internal stress of the material.

[0049] The fixing fixture is provided with a threaded hole passing through it, the base 1 is provided with a threaded blind hole, and the lower end of the tensile connecting rod 8 is provided with an external thread. During assembly, the fixing fixture is detachably connected to the base 1 through the tensile connecting rod 8 that passes through the threaded hole and is connected to the threaded blind hole; thereby, the fixing fixture is firmly pressed against the base 1 to form a stable lower frame.

[0050] The positioning portion is a plurality of positioning holes axially arranged on the tensile connecting rod 8, and the mobile clamp is provided with connecting holes adapted to the positioning holes. When setting the strain, the operator pulls the mobile clamp to a certain height so that its connecting hole is aligned with a specific positioning hole on the connecting rod, and then passes a positioning pin 10 through the two holes at the same time, firmly locking the position of the mobile clamp, thereby realizing the setting of the tensile deformation amount.

[0051] To ensure that the specimen is clamped securely and evenly to avoid slipping or stress concentration during testing, both the fixed and movable fixtures consist of two independent clamping blocks, between which the specimen is sandwiched.

[0052] That is, the fixed fixture includes a first lower clamping block 4 and a second lower clamping block 5, and the lower end of the tensile specimen 9 is clamped between the first lower clamping block 4 and the second lower clamping block 5; the movable fixture includes a first upper clamping block 6 and a second upper clamping block 7, and the upper end of the tensile specimen 9 is clamped between the first upper clamping block 6 and the second upper clamping block 7.

[0053] The first and second lower clamping blocks 4 and 5, as well as the first and second upper clamping blocks 6 and 7, are connected by clamping bolts 11 and clamping nuts 12. There are at least three clamping bolts 11 and clamping nuts 12, located at three different locations on the tensile specimen 9. This multi-point, multi-directional tightening design aims to evenly distribute the clamping force across the specimen, effectively preventing specimen damage or measurement errors caused by excessive force at a single point.

[0054] Example 3 like Figure 4 and Figure 5As shown, this embodiment focuses on the specific structure of the compression test module, and elaborates on the construction and connection method of its internal components and the complete mechanical process for achieving precise strain setting.

[0055] The compression fixture includes a compression plate 19 , an upper plate 18 and a compression connecting rod 17 .

[0056] The compression connecting rod 17 is used to connect the upper plate 18 and the base 1 to form a closed force-bearing frame.

[0057] The compression specimen 20 is placed on the base 1 and is located below the compression plate 19. The compression plate 19 is a component that directly contacts the compression specimen 20 and applies a load. The force sensor is a pressure sensor 15 and is arranged between the compression plate 19 and the upper plate 18 to transfer the load of the upper plate 18 to the compression plate 19.

[0058] The limit blocks 16 are a group of limit blocks 16 with different heights, which are used to set different compression deformation amounts by selecting limit blocks 16 of different heights. Technicians can select one with a specific target height from this group of limit blocks 16 according to the requirements of the experimental plan.

[0059] During testing, the selected stopper 16 is placed on the base 1, next to the compression specimen 20. When the compression plate 19 is pressed downward by the fastening device, its bottom eventually contacts and is firmly supported by the upper surface of the stopper 16. Because the stopper 16 is made of a highly rigid material, its height prevents the compression plate 19 from descending further. The final height of the compression specimen 20 after compression is precisely locked to the height of the selected stopper 16, thus achieving a precise setting of the compression deformation.

[0060] A threaded blind hole is provided on the base 1, and the lower section of the compression connecting rod 17 is provided with a lower section thread adapted to the threaded blind hole; by screwing the connecting rod into the base 1, it can be firmly fixed at the bottom.

[0061] The upper plate 18 is provided with a through hole corresponding to the compression connecting rod 17. The upper section of the compression connecting rod 17 is provided with an upper thread. The upper section of the compression connecting rod 17 passes through the through hole and is restrained by the compression nut 13. By tightening the compression nut 13, downward pressure is applied to the upper plate 18, causing the upper plate 18 and the compression plate 19 to move downward synchronously until the compression plate 19 is stopped by the stop block 16. The compression nut 13 is the actuator for applying and locking the preload force, and to prevent slippage, a gasket 14 is provided between the compression nut 13 and the upper plate 18 bracket.

[0062] Example 4 This embodiment provides a testing method for a modular rubber stress relaxation testing device. Based on the modular rubber stress relaxation testing device described above, the testing method includes tensile relaxation stress testing and compressive relaxation stress testing. The testing process is as follows: first, a constant strain is applied to the specimen using the mechanical structure of the device; second, the specimen in a constant strain state is placed in a specific temperature environment; finally, a sensor system is used to continuously monitor and record the natural decay of its internal stress over time.

[0063] A tensile relaxation stress test method is provided, comprising the following steps: The two ends of a tensile specimen 9 (eg, a dumbbell-shaped specimen) are clamped between a fixed fixture and a movable fixture, respectively.

[0064] The operator moves the movable fixture upward to a predetermined position, inserts the positioning pin 10 into the selected positioning hole on the tensile connecting rod 8, fixes the position of the movable fixture, and sets the tensile deformation of the tensile specimen 9.

[0065] The tensile testing module with the set tensile deformation is placed in the thermal insulation box 21 to create the required testing temperature environment.

[0066] The tension sensor 3 is connected to the data recording device 2 to record the initial tensile force and the change in the tensile stress value over time at a preset temperature. After the insulated box 21 reaches and maintains the preset temperature, the data recording device 2 begins to continuously and in real time record the value of the tensile force decaying over time.

[0067] Calculate the ratio of the tensile stress value to the initial tensile force, and draw a curve describing the change of the ratio over time. This curve is the tensile stress relaxation curve of the material under this condition.

[0068] Finally, the testing device is taken out from the heat preservation box 21 , the clamp is disassembled and the tensile specimen 9 is taken out. After the tensile specimen 9 is cooled at room temperature for at least 12 hours, the tensile permanent deformation value of the tensile specimen 9 is measured.

[0069] The test method includes a compression relaxation stress test method, comprising the following steps: A compression specimen 20 (eg, a cylindrical specimen) is placed on the base 1 , and a stopper 16 of a specific height is selected from a group of stoppers 16 with different heights and placed on the base 1 .

[0070] The compression plate 19 , the pressure sensor 15 , and the upper plate 18 are assembled in sequence above the compression specimen 20 .

[0071] By tightening the compression nut 13 for limiting the compression connecting rod 17 , the compression plate 19 is pressed down until it is supported by the limiting block 16 , thereby setting the compression deformation of the compression specimen 20 .

[0072] Place the compression test module with set compression deformation in the heat preservation box 21; The pressure sensor 15 is connected to the data recording device 2 to record the initial compression force and the change of the compression stress value over time at a preset temperature.

[0073] The ratio of the compressive stress value to the initial compressive force is calculated to obtain the compressive stress relaxation curve.

[0074] Finally, the test device is taken out from the heat preservation box 21 , the clamp is disassembled and the compression sample 20 is taken out. After the compression sample 20 is cooled at room temperature for at least 12 hours, the tensile permanent deformation value of the compression sample 20 is measured.

[0075] Example 5 This embodiment further describes a method for performing a derived stress relaxation test using the modular testing device disclosed in the aforementioned embodiment, including a step-by-step temperature rise test and a step-by-step strain loading test.

[0076] First, perform the basic process test as in Example 4, and then perform the derivative test: Step-by-step heating test: In the data acquisition step of the basic process, after the target temperature is maintained for a period of time, the temperature in the insulation box 21 can be further increased in stages to multiple new temperature platforms, and maintained at each platform for a period of time to obtain the stress response data of the material at different temperatures.

[0077] Stepped tensile strain loading test: In the data acquisition step of the basic process, after the constant strain is maintained for a period of time, the operator can pull out the positioning pin 10 and move it to the next positioning hole on the tensile connecting rod 8 to achieve a step-by-step increase in tensile strain, which is used to study the influence of different strain levels on the stress relaxation behavior of the material.

[0078] Stepped compressive strain loading test: In the basic process of compression testing, after the specimen is kept under constant strain for a period of time using the first limit block 16 of a specific height, the operator rotates and loosens the compression nut 13 to release the downward pressure on the upper plate 18, separating the compression plate 19 from the specimen and the limit block 16; from a group of limit blocks 16 with different heights, a lower limit block 16 is selected and replaced, and the compression nut 13 is tightened clockwise again to press the compression plate 19 down again until it is firmly supported by the new, lower limit block 16, so as to achieve a step-by-step increase in compressive strain, which is used to study the influence of different strain levels on the stress relaxation behavior of the material.

[0079] In the description of this specification, the description with reference to the terms "one embodiment / method", "some embodiments / methods", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment / method or example are included in at least one embodiment / method or example of the present application. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment / method or example. Moreover, the specific features, structures, materials or characteristics described may be combined in an appropriate manner in any one or more embodiments / methods or examples. In addition, those skilled in the art may combine and combine different embodiments / methods or examples described in this specification and the features of different embodiments / methods or examples, unless they are contradictory.

[0080] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. Throughout the description of this application, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0081] It should be understood by those skilled in the art that the above embodiments are merely for the purpose of illustrating the present invention clearly, and are not intended to limit the scope of the present invention. For those skilled in the art, other changes or modifications may be made based on the above invention, and these changes or modifications are still within the scope of the present invention.

Claims

1. A modular rubber stress relaxation testing device, characterized in that: include: Base (1); A tensile assembly is detachably connected to the base (1) to form a tensile test module, the tensile assembly comprising: a tensile clamp for clamping a tensile specimen (9) and a tensile connecting rod (8), the tensile connecting rod (8) being provided with a plurality of positioning portions, the positioning portions being used to fix the spacing of the tensile clamps to set the tensile deformation of the tensile specimen (9); A compression assembly is detachably connected to the base (1) to form a compression test module, the compression assembly comprising: a compression fixture and a limit block (16) for applying a load to the compression specimen (20), the limit block (16) being arranged between the compression fixture and the base (1), the limit block (16) being used to limit the position of the compression surface of the compression fixture relative to the base (1) to set the compression deformation of the compression specimen (20); A force sensor is used to measure tensile force when constituting a tensile test module, or is used to measure compressive force when constituting a compressive test module.

2. A modular rubber stress relaxation testing device according to claim 1, characterized in that: It also includes an insulation box (21) and a data recording device (2), wherein the tensile test module or the compression test module is arranged in the insulation box (21); and the data recording device (2) is arranged outside the insulation box (21) and is electrically connected to the force sensor.

3. A modular rubber stress relaxation testing device according to claim 2, characterized in that: The tensile clamp comprises: a fixed clamp and a movable clamp, wherein the fixed clamp is detachably connected to the base (1) and / or the lower end of the tensile connecting rod (8), and clamps the lower end of the tensile specimen (9); the movable clamp is connected to the tensile connecting rod (8) via a positioning portion, and clamps the upper end of the tensile specimen (9); the force sensor is a tensile force sensor (3) and is connected to the movable clamp.

4. A modular rubber stress relaxation testing device according to claim 3, characterized in that: The fixing fixture is provided with a threaded hole extending therethrough, the base (1) is provided with a threaded blind hole, the lower end of the stretching connecting rod (8) is provided with an external thread, and the fixing fixture is detachably connected to the base (1) via the stretching connecting rod (8) which passes through the threaded hole and is connected to the threaded blind hole; The positioning portion is a plurality of positioning holes axially arranged on the stretch connecting rod (8), the movable clamp is provided with a connecting hole adapted to the positioning hole, and the movable clamp is connected via a positioning pin (10) passing through the positioning hole and the connecting hole.

5. The modular rubber stress relaxation testing device according to claim 3, characterized in that: The fixing fixture comprises a first lower clamping block (4) and a second lower clamping block (5), and the lower end of the tensile specimen (9) is clamped between the first lower clamping block (4) and the second lower clamping block (5); The movable clamp comprises a first upper clamping block (6) and a second upper clamping block (7), and the upper end of the tensile specimen (9) is clamped between the first upper clamping block (6) and the second upper clamping block (7); The first lower clamping block (4) and the second lower clamping block (5), and the first upper clamping block (6) and the second upper clamping block (7) are all connected via clamping bolts (11) and clamping nuts (12).

6. A modular rubber stress relaxation testing device according to claim 5, characterized in that: The number of the clamping bolts (11) and the clamping nuts (12) is at least three, and they are respectively located at three different positions of the tensile specimen (9).

7. The modular rubber stress relaxation testing device according to claim 2, characterized in that: The compression fixture comprises: a compression plate (19), an upper plate (18) and a compression connecting rod (17), wherein the compression connecting rod (17) is used to connect the upper plate (18) to the base (1); the compression specimen (20) is placed on the base (1) and is located below the compression plate (19); The force sensor is a pressure sensor (15) and is arranged between the compression plate (19) and the upper plate (18) and is used to transmit the load of the upper plate (18) to the compression plate (19); The limit blocks (16) are a group of limit blocks (16) with different heights, and are used to set different compression deformation amounts by selecting limit blocks (16) with different heights.

8. The modular rubber stress relaxation testing device according to claim 7, characterized in that: The base (1) is provided with a threaded blind hole, and the lower section of the compression connecting rod (17) is provided with a lower section thread adapted to the threaded blind hole; The upper plate (18) is provided with a through hole corresponding to the compression connecting rod (17), the upper section of the compression connecting rod (17) is provided with an upper thread, and the upper section of the compression connecting rod (17) passes through the through hole and is limited by the compression nut (13).

9. A testing method for a modular rubber stress relaxation testing device, characterized in that: Based on a modular rubber stress relaxation testing device according to any one of claims 2 to 8, the testing method includes a tensile relaxation stress testing method, comprising the following steps: Clamping the two ends of the tensile specimen (9) between a fixed fixture and a movable fixture respectively; Inserting the positioning pin (10) into the selected positioning hole on the tensile connecting rod (8) to fix the position of the movable fixture and set the tensile deformation of the tensile specimen (9); Placing the tensile test module with the set tensile deformation amount in the heat preservation box (21); Connecting a tensile force sensor (3) to the data recording device (2), recording the initial tensile force, and recording the change in tensile stress value over time at a preset temperature; The ratio of the tensile stress value to the initial tensile force was calculated to obtain the tensile stress relaxation curve.

10. The testing method of a modular rubber stress relaxation testing device according to claim 9, characterized in that: The test method includes a compression relaxation stress test method, comprising the following steps: The compression specimen (20) is placed on the base (1), and a stop block (16) of a specific height is selected from a group of stop blocks (16) with different heights and is placed on the base (1); Assembling the compression plate (19), the pressure sensor (15) and the upper plate (18) in sequence above the compression specimen (20); By tightening the compression nut (13) for limiting the compression connecting rod (17), the compression plate (19) is pressed down until it is supported by the limiting block (16), thereby setting the compression deformation of the compression specimen (20); Placing the compression test module with the set compression deformation amount in the heat preservation box (21); connecting a pressure sensor (15) to a data recording device (2) to record the initial compression force and the change in the compression stress value over time at a preset temperature; The ratio of the compressive stress value to the initial compressive force is calculated to obtain the compressive stress relaxation curve.

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