Compression creep test tool and test method

Abstract

The invention relates to the technical field of mechanical testing of materials, and discloses a compression creep test tool and a test method.The compression creep test tool is ingenious in design and mainly comprises an upper clamp, a lower clamp, a pin, an extensometer, a cushion block and the like. The tool fixes the upper and lower clamps through a pin structure to ensure the stability of the test device. The extensometer and the clamp move synchronously, creep deformation of the sample is monitored in real time, an electric signal is transmitted to a control system through a cable to be analyzed, and the creep rate and the total deformation are calculated. In order to improve the test efficiency and accuracy, coaxial guide and translation guide designs are introduced in the second embodiment, so that the test sample is quickly put in and taken out, and the coaxiality of the clamp is ensured. In the third embodiment, the stability and reliability of the experiment in a long term and a short term are ensured by introducing a pressure source switching mechanism and utilizing gravity traction and a mechanical traction assembly. The whole tool is easy and convenient to assemble and convenient to operate, and important data support is provided for material performance research and structural design.

Description

Technical Field

[0001] The invention relates to the technical field of material mechanics testing, in particular to a compression creep test tool and a test method. Background Art

[0002] The compression creep test is a material mechanics test method that applies continuous compression force to the material under specific conditions to observe and record the deformation behavior of the material under long-term action. This method aims to evaluate the stability, durability and creep performance of the material under pressure, and is of great significance for material performance research, structural design and safety assessment.

[0003] The existing compression creep test tooling has the following main shortcomings:

[0004] 1. Fixture falling off and stability issues: Some traditional compression creep test fixtures use threaded structures, which can easily lead to thread aging and damage in long-term high-temperature experimental environments, causing the fixture to fall off, affecting experimental accuracy and safety.

[0005] 2. It is difficult to put in samples and the efficiency is low: some tooling samples are inconvenient to put in and take out, and manual clamps need to be disassembled before putting in the samples. The operation is cumbersome and it is difficult to meet the needs of rapid testing.

[0006] 3. Long-term experimental pressure source reliability issues: Traditional electric or hydraulic drive sources may have failure risks in long-term applications, affecting the stability and reliability of the experiment.

[0007] In the face of the above problems, we propose a compression creep test tool and test method to solve the problems in the above background. Summary of the invention

[0008] The purpose of the present invention is to provide a compression creep test fixture and test method to solve the problem that the existing compression creep test fixture mentioned in the above background technology mainly uses a threaded structure for connection, and the threaded structure is easily damaged by the test temperature, which affects the service life.

[0009] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0010] A compression creep test fixture comprises a compression component and a creep measurement component; the compression component cooperates with a permanent creep tester to compress a sample to be tested, the compression component comprises an upper clamp and a lower clamp, both the upper clamp and the lower clamp are U-shaped rods, the upper clamp and the lower clamp are buckled with each other, the open end of the upper clamp is connected to an upper chuck via a pin, and the open end of the lower clamp is connected to a lower chuck via a pin; two groups of creep measurement components are provided and are respectively fixed to the upper clamp or the lower clamp by plug-in type via pins.

[0011] A test method for a compression creep test fixture:

[0012] S1. Install pad 1 and pad 2 on the upper fixture and the lower fixture respectively, place the test sample between pad 1 and pad 2, and use the extensometer to pin the fixture to achieve synchronous movement;

[0013] S2. The upper clamp and the lower clamp are buckled together, and the upper clamp and the lower clamp are respectively connected to the corresponding upper chuck and the lower chuck through the pin structure to ensure their stability;

[0014] S3. The upper chuck and the lower chuck are connected respectively by an upper pull rod and a lower pull rod to apply an upward pulling force and a downward pressure;

[0015] S4. The upper chuck and the lower chuck are respectively connected to a pressure source switching mechanism. During the experiment, the pressure source is switched by an electric push rod as needed to achieve gravity traction or mechanical traction;

[0016] S5. Ensure that the coaxial guide rod cooperates with the coaxial guide groove to ensure the coaxiality of the upper fixture and the lower fixture. When the limit block enters the limit groove, the proximity switch is triggered. When the active offset assembly works normally, the lower fixture is pushed to offset relative to the upper fixture, so that the test sample can be quickly and conveniently placed in and taken out.

[0017] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0018] The compression creep test fixture of the present invention effectively solves the stability and convenience problems of long-term creep tests by designing a unique mechanical structure and a pressure source switching mechanism, and significantly improves the accuracy and efficiency of the test. Its working principle is: the sample to be tested is fixed by the upper and lower clamps and the pin structure, and the compression pressure is applied by the tension provided by the persistent creep tester. At the same time, the extensometer records the deformation changes of the sample in real time and converts them into electrical signals. The control system analyzes and calculates key parameters such as creep rate and total deformation. In order to facilitate and quickly replace the test sample, a sliding device and a coaxial guide rod are designed to ensure that the coaxiality between the clamps is maintained during the sample replacement process. At the same time, in order to avoid the failure of the traditional drive source during long-term use, a pressure source switching mechanism is specially introduced. Through the combination of the gravity traction component and the mechanical traction component, the pressure source can be flexibly switched according to the experimental requirements to ensure the stability and reliability of the experiment. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the overall external structure of the first embodiment of the present invention;

[0020] Figure 2 This is a schematic diagram of the bottom structure of the first embodiment of the present invention;

[0021] Figure 3Schematic diagram of the upper clamp structure of the first embodiment of the present invention;

[0022] Figure 4 Schematic diagram of the lower clamp structure of the first embodiment of the present invention;

[0023] Figure 5 It is a schematic diagram of the unfolded structure of the upper clamp of the first embodiment of the present invention;

[0024] Figure 6 This is a schematic diagram of the unfolded structure of the lower clamp of the first embodiment of the present invention;

[0025] Figure 7 It is a schematic diagram of the overall side view structure of the second embodiment of the present invention;

[0026] Figure 8 It is a schematic diagram of the expanded structure of the upper clamp and the lower clamp of the second embodiment of the present invention;

[0027] Fig. 9 It is a schematic diagram of the overall side cross-sectional structure of the second embodiment of the present invention;

[0028] Fig.10 This is a schematic diagram of the installation position structure of the coaxial guide rod according to the second embodiment of the present invention;

[0029] Fig.11 This is a schematic diagram of the side view structure of the upper clamp of the second embodiment of the present invention;

[0030] Fig.12 This is a schematic diagram of the structure of an active offset assembly according to a second embodiment of the present invention;

[0031] Fig.13 It is a schematic diagram of the upper structure of the third embodiment of the present invention;

[0032] Fig.14 It is a schematic diagram of the top view of the structure of the third embodiment of the present invention;

[0033] Fig.15 For the present invention Fig.14 A schematic diagram of the structure at the local A of the enlarged part;

[0034] Fig.16 It is a schematic diagram of the expanded structure of the bevel gear assembly of the present invention.

[0035] Among them: 1. Upper chuck; 2. Pin 1; 3. Upper clamp; 4. Pad 2; 5. Positioning pin; 6. Pad 1; 7. Clamping hole; 8. Extensometer 1; 9. Lower clamp; 10. Clamping groove; 11. Extensometer 2; 12. Extensometer clip; 13. Pin 2; 14. Lower chuck; 21. Coaxial guide rod; 22. Translation guide block; 23. Coaxial guide groove; 24. Translation guide groove; 25. Limiting groove; 26. Limiting block; 27. Clamping block; 28. Connecting shaft; 29. ​​Mounting seat; 30. Electric telescopic rod; 3 1. Stabilizing frame; 32. Top frame; 301. Pulley frame; 302. First pulley; 303. Second pulley; 304. Traction rope; 305. Weight plate; 306. Electric push rod 1; 307. Support plate; 308. Turning knob; 311. Driving screw; 312. Lifting slide; 313. First bevel gear; 314. Second bevel gear; 315. Servo motor; 316. Electric push rod 2; 317. Fixing plate; 318. Driving block; 401. Connecting sleeve; 402. Tension sensor; 403. Latch. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] Embodiment 1:

[0038] See also Figure 1-6 , the present invention provides a technical solution:

[0039] A compression creep test fixture and test method, comprising a compression component and a creep measurement component;

[0040] like Figure 1 As shown, the compression assembly includes an upper clamp 3 and a lower clamp 9, both of which are U-shaped rods, and the upper clamp 3 and the lower clamp 9 are buckled with each other, the upper clamp 1 is installed at the open end of the upper clamp 3, and the lower clamp 14 is connected to the open end of the lower clamp 9;

[0041] Furthermore, pin holes are provided on both sides of the open end of the upper clamp 3, and a pin 2 is installed between the upper clamp 3 and the upper clamp 1. The pin 2 passes through both sides of the open end of the upper clamp 3 and the interior of the upper clamp 1, and the side surface of the upper clamp 1 fits with the inner side of the upper clamp 3, thereby fixing the upper clamp 1 inside the upper clamp 3; the connection method between the lower clamp 14 and the lower clamp 9 is the same as the connection method between the upper clamp 1 and the upper clamp 3;

[0042] Furthermore, the pin 1 2 is a spring pin, and after passing through the two ends of the upper clamp 1 and the upper fixture 3, the spring end automatically pops out to prevent falling off, thereby ensuring the stability of the device.

[0043] The creep measurement assembly includes two extensometers 1 8 and two extensometers 2 11. The two extensometers 1 8 are connected to one end of the upper fixture 3 away from the upper clamp 1, and the two extensometers 2 11 are connected to one end of the lower fixture 9 away from the lower clamp 14.

[0044] The compression assembly is connected to the endurance creep tester and works in coordination, the upper clamp 3 of the compression assembly is fixedly connected to the upper pull rod of the endurance creep tester, and the lower clamp 9 of the compression assembly is fixedly connected to the lower pull rod of the endurance creep tester;

[0045] Furthermore, a pad 6 is installed on the inner side of one end of the upper clamp 3 away from the upper chuck 1, and a pad 2 4 is installed on the inner side of one end of the lower clamp 9 away from the lower chuck 14. Positioning grooves are provided inside pads 1 6 and 2 4. The two ends of the test sample are respectively engaged with the positioning grooves of pads 1 6 and 2 4, so that the test sample remains stable and prevents it from sliding or tilting during the compression creep experiment, which is beneficial to improving the accuracy of the compression creep test data.

[0046] The upper pull rod of the creep testing machine is connected to the upper chuck 1 to provide an upward pulling force, and the lower pull rod is connected to the lower chuck 14 to provide a downward pulling force, thereby applying pressure to the test sample placed between the pad 1 6 and the pad 2 4. The creep testing machine applies a load to the pull rod to achieve the compression function of the test sample. The compression creep amount of the sample is measured by the extensometer assembled on the upper clamp 3 and the lower clamp 9 as described below.

[0047] The above design meets the coaxiality requirement of the compression creep test, and it should be particularly pointed out that the fixture abandons the threaded structure and chooses a pin structure instead, thereby avoiding the phenomenon of damage to the test fixture due to excessively high experimental temperature and increasing the service life of the test fixture.

[0048] Furthermore, the connection method of the extensometer 8 and the upper clamp 3 is as follows: the two extensometers 8 are located on both sides of the upper clamp 3, an extensometer clip 12 is arranged between the two extensometers 8, the extensometer clip 12 is located on the outer side of one end of the upper clamp 3 close to the cushion block 6, and the cushion block 6, one side of the upper clamp 3 close to the extensometer clip 12 and the middle of the extensometer clip 12 are coaxially provided with a socket, a pin 2 13 is arranged inside the pin hole, and the pin 2 13 passes through the sockets of the cushion block 6, the upper clamp 3 and the extensometer clip 12, thereby connecting and fixing the cushion block 6, the upper clamp 3 and the extensometer clip 12.

[0049] Both ends of the extensometer clip 12 are provided with snap-on holes 7, and one end of the extensometer 8 is provided with a mounting hole. A positioning pin 5 is inserted between the mounting hole and the snap-on hole 7. The extensometer 8 and the extensometer clip 12 are connected and fixed by the positioning pin 5, so that the extensometer 8 moves synchronously with the upper fixture 3, and the displacement of the upper fixture 3 is accurately measured;

[0050] The difference between the connection mode of the extensometer 11 and the lower fixture 9 and the connection mode of the extensometer 1 and the upper fixture 3 is that: an axial hole is coaxially provided between the lower fixture 9 and the cushion block 4, a long pin is inserted into the axial hole, the long pin passes through the interior of the lower fixture 9 and the cushion block 4, and the two ends of the long pin extend to the exterior of the two sides of the lower fixture 9, and a clamping groove 10 is provided at the end of the long pin located outside the lower fixture 9. The end of the extensometer 11 and the extensometer 1 are also provided with a mounting hole, and the positioning pin 5 passes through the mounting hole of the extensometer 11 and the interior of the clamping groove 10, so that the extensometer 11 is fixedly connected with the long pin, so that the long pin moves with the lower fixture 9, and the extensometer 11 moves with the long pin, thereby accurately measuring the displacement of the lower fixture 9;

[0051] During the compression creep process, the displacement of the upper clamp 3 and the lower clamp 9 is monitored, so that the deformation of the test sample during the compression creep process can be calculated.

[0052] In the compression creep test, the specimen will slowly creep under the action of continuous compression force. In order to monitor this deformation, we connect the upper fixture 3 and the lower fixture 9 to the extensometer respectively. The extensometer is a high-precision sensor with a built-in displacement sensor, such as a strain gauge or a photoelectric sensor, which can convert tiny length changes into electrical signals. The extensometer is fixed to the fixture by the extensometer clip 12 or a long pin as a connector, ensuring its synchronous movement with the fixture. When the specimen creeps, the extensometer 18 moves with the connected upper fixture 3, and the extensometer 2 11 moves with the lower fixture 9. This movement causes the length of the extensometer 8 to change, which in turn causes the strain change on the strain gauge, converting the displacement change into electrical signals, which are then transmitted to the control system of the permanent creep tester via cables. The control system records and analyzes these electrical signals in real time, converts them into displacement data, and then calculates parameters such as creep rate and total deformation to realize the monitoring and evaluation of the creep behavior of the specimen. Through this series of steps, the testing machine can accurately monitor the deformation changes of the specimen during the compression creep process.

[0053] Embodiment 2:

[0054] See also Figure 7-12 , and combined with Example 1, further obtaining:

[0055] In order to facilitate the quick and convenient placement of the test sample between the pad 1 6 and the pad 2 4 inside the upper clamp 3 and the lower clamp 9 during the compression creep experiment, the lower clamp 9 can slide horizontally relative to the upper clamp 3 at a limited position, so that the space between the upper clamp 3 and the lower clamp 9 is opened, so that the test sample can be conveniently and quickly placed on the pad 1 6, and then the lower clamp 9 and the pad 2 4 are reset, so that the pad 2 4 and the pad 1 6 slide coaxially, thereby compacting the test sample, which is conducive to stable and effective compression creep testing of the test sample. When the experiment is completed, the above steps are reversed to remove the test sample from between the upper clamp 3 and the lower clamp 9, which facilitates the experimental operation and avoids the need to disassemble the upper clamp 3 and the lower clamp 9 and their connected accessories when taking and placing the test sample, resulting in complicated operation and low efficiency.

[0056] The difference from Example 1 is that the distance between the inner walls on both sides of the upper clamp 3 is greater than the width of the lower clamp 9, and preferably, the distance between the inner walls on both sides of the upper clamp 3 is three times the width of the lower clamp 9. During the compression creep test, the lower clamp 9 is located in the middle of the upper clamp 3, and the pad 1 6 and the pad 2 4 move along the axis of the positioning groove with the upper clamp 3 and the lower clamp 9 respectively, so that the pad 1 6 and the pad 2 4 are closer or farther away from each other.

[0057] A coaxial guide groove 23 is provided at one end of the upper clamp 3 near the pad 6, and a translation guide groove 24 is connected to one side of the coaxial guide groove 23. The translation guide groove 24 is perpendicular to the coaxial guide groove 23. A coaxial guide rod 21 is fixedly connected to the inner side of the lower clamp 9. The shape of the coaxial guide rod 21 is adapted to the inner side of the guide groove. A translation guide block 22 is fixedly connected to one end of the inner side of the lower clamp 9 near the lower clamp 14. The translation guide block 22 can slide along the inner side of the coaxial guide groove 23. When it moves to the position where the coaxial guide groove 23 is connected to the translation guide groove 24, the coaxial guide rod 21 is separated from the inner side of the guide groove, and the translation guide block 22 can slide along the inner side of the translation guide groove 24.

[0058] Furthermore, a limit block 26 is provided at one end of the lower clamp 9 close to the upper clamp 1, and a limit groove 25 adapted to the limit block 26 is opened on one side of the upper clamp 1 close to the limit block 26. The limit groove 25 and the translation guide groove 24 are located on the same side of the coaxial guide groove 23 and have the same length.

[0059] Furthermore, a proximity switch 1 is installed on the top of the limit block 26. When the limit block 26 conflicts with the inside of the limit groove 25, the proximity switch 1 on the limit block 26 is triggered, and the electrical signal of the proximity switch is transmitted to the control system of the creep tester to prompt the lower clamp 9 and the limit block 26 to move to the top. At this time, the translation guide block 22 moves to the end of the translation guide groove 24, and the translation guide block 22 can slide into the translation guide groove 24. At the same time, the coaxial guide rod 21 is separated from the inside of the guide groove, and the lower clamp 9 can slide horizontally perpendicular to the axis direction of the positioning groove. The lower clamp 9 is offset to one side of the middle part of the upper clamp 3, thereby opening the space between the upper clamp 3 and the lower clamp 9. Since the lower clamp 9 and the limit block 26 move to the top at this time, the distance between the pad 1 6 and the pad 2 4 is the largest, it is very convenient to put the test sample between the pad 1 6 and the pad 2 4, and place the test sample in the positioning groove on the side of the pad 1 6;

[0060] Then move the lower clamp 9 to reset it to the middle of the upper clamp 3, the pad 2 4 is located directly above the pad 1 6, the positioning grooves of the pad 2 4 and the pad 1 6 are on the same axis, and the translation guide block 22 is moved to the inside of the coaxial guide groove 23, and the coaxial guide rod 21 and the coaxial guide groove 23 are located on the same straight line, and the upper pull rod of the endurance creep tester applies an upward pulling force to the upper chuck 1, and the lower pull rod applies a downward pulling force to the lower chuck 14, thereby applying pressure to the test sample between the pad 1 6 and the pad 2 4, and the pull rod is applied by the endurance creep tester. By adding load, the compression function of the test sample is realized. As the upper pull rod of the permanent creep testing machine applies an upward pulling force to the upper chuck 1 and the lower pull rod applies a downward pulling force to the lower chuck 14, the coaxial guide rod 21 always slides inside the coaxial guide groove 23, and the upper clamp 3 and the lower clamp 9 both move along the direction of the coaxial guide groove 23, so that the positioning grooves of the pad 2 4 and the pad 1 6 are always on the same axis, ensuring the coaxiality requirements of the compression creep test. Through the above steps, the testing machine can accurately test the deformation changes of the sample during the compression creep process.

[0061] A proximity switch 2 is provided inside one end of the translation guide groove 24 away from the coaxial guide groove 23, and a proximity switch 3 is provided inside one side of the translation guide block 22 away from the translation guide groove 24. When the proximity switch 3 on the translation guide block 22 fits with the coaxial guide groove 23, the proximity switch 3 is triggered to prompt that the translation guide block 22 is completely inside the coaxial guide groove 23. At this time, the upper clamp 3 and the lower clamp 9 keep coaxial movement in the axial direction of the positioning groove.

[0062] When the proximity switch 2 is triggered, it indicates that the translation guide block 22 enters the translation guide slot 24 away from the end of the coaxial guide slot 23. At this time, the lower fixture 9 is offset to one side of the upper fixture 3, which is convenient for placing or removing the sample to be tested.

[0063] The working principle of proximity switch 2 and proximity switch 3 is the same as that of the proximity switch on the limit block 26;

[0064] Furthermore, in order to prevent the connection between the lower pull rod and the lower clamp 14 of the persistent creep testing machine from affecting the displacement of the lower clamp 9, an active displacement component is installed on the lower clamp 14, and the lower clamp 14 includes a clamp block 27 and a connecting shaft 28. The connecting shaft 28 and the clamp block 27 are movably connected. The lower pull rod of the persistent creep testing machine is fixedly connected to the connecting shaft 28 of the lower clamp 14, and the clamp block 27 is connected to the end of the lower clamp 9. A slide groove is provided at one end of the clamp block 27 close to the connecting shaft 28, and a displacement slide is slidably connected inside the slide groove. The connecting shaft 28 is fixedly connected to the middle part of the side of the displacement slide away from the lower clamp 9, and a mounting seat 29 is provided at one end of the displacement slide. An electric telescopic rod 30 is fixedly connected inside the mounting seat 29, and the telescopic end of the electric telescopic rod 30 is fixedly connected to the side of the clamp block 27; and the circuit of the electric telescopic rod 30 is connected to the control system of the persistent creep testing machine for controlling the extension and retraction of the electric telescopic rod 30.

[0065] When the lower clamp 9 needs to be offset, the electric telescopic rod 30 pushes the lower clamp 9 to offset to the side where the translation guide groove 24 is provided on the upper clamp 3;

[0066] When the test sample is installed or removed, the electric telescopic rod 30 contracts to restore the lower clamp 9 to the middle of the upper clamp 3. At the same time, the connecting shaft 28 is located in the middle of the lower end of the clamp block 27, which is conducive to the stable pressure and tension of the lower pull rod of the creep tester on the lower clamp 14.

[0067] Embodiment three:

[0068] See also Figure 13-16 , and combined with Example 2, further obtained:

[0069] When conducting long-term experiments, traditional electric drive sources and hydraulic drives may fail. Therefore, a compression creep test fixture is designed that can switch the pressure source between long-term creep experiments or short-term creep experiments.

[0070] The difference from the second embodiment is that the present device is further provided with a stabilizing frame 31 and a pressure source switching mechanism, one end of the stabilizing frame 31 is fixedly connected to the endurance creep tester, the compression assembly is slidably arranged inside the stabilizing frame 31, and the upper chuck 1 and the lower chuck 14 in the compression assembly are respectively provided with a pressure switching assembly, and the pressure switching assembly includes a gravity traction assembly and a mechanical traction assembly;

[0071] Taking the connection relationship between the above chuck 1 and the pressure switching assembly as an example, the installation and working principle of the pressure switching assembly are explained. The connection method of the pressure switching assembly and the lower chuck 14 are similar, and the working principle is the same, so it will not be repeated.

[0072] One end of the stabilizing frame 31 close to the upper clamp 1 is fixedly connected to a top frame 32, the top frame 32 is U-shaped, and its U-shaped open end is fixedly connected to the upper end of the stabilizing frame 31, and the stabilizing frame 31 provides fixed support for the top frame 32;

[0073] The gravity traction assembly and the mechanical traction assembly are installed on the top frame 32, and the top frame 32 keeps the gravity traction assembly and the mechanical traction assembly stable. The gravity traction assembly includes a pulley frame 301, on which a first pulley 302 and a second pulley 303 are installed. The pulley frame 301 is also provided with a traction rope 304, which passes through the upper part of the first pulley 302 and the second pulley 303, and its two ends are vertically downward, and one end of the traction rope 304 is connected to the upper clamp. 1, and the other end thereof is fixedly connected with a weight plate 305, the weight plate 305 is used to place weights, and the weights and the weight plate 305 generate tension on the traction rope 304; the first pulley 302 is arranged above the upper clamp 1, and the second pulley 303 is arranged on the outer side of the upper end of the top frame 32, so that the top frame 32 does not affect the natural falling of the weight plate 305, and the traction rope 304 generates a vertical upward pulling force on the upper clamp 1 through the second pulley 303;

[0074] Furthermore, a connecting assembly is provided between the traction rope 304 and the upper clamp 1, and the connecting assembly includes a connecting sleeve 401 and a tension sensor 402. One end of the tension sensor 402 is fixedly connected to the connecting sleeve 401. The connecting sleeve 401 is sleeved on the outer part of the upper end of the traction head and is plugged and fixed by a pin 403. A knob 308 is provided between the traction rope 304 and the pressure sensor, and the traction rope 304 and the tension sensor 402 are rotationally connected by the knob 308.

[0075] An electric push rod 306 is fixedly installed on the outer side of one end of the pulley frame 301 close to the second pulley 303. The telescopic end of the electric push rod 306 is fixedly connected to a support plate 307 that is compatible with the bottom of the weight plate 305. The support plate 307 is arranged below the weight plate 305. When the electric push rod 306 contracts, it drives the support plate 307 to lift the weight plate 305, so that the weight and the weight plate 305 do not generate pulling force on the traction rope 304, thereby switching the pressure source of the compression creep tooling to control the gravity traction component between the traction state and the non-traction state.

[0076] The mechanical traction assembly includes a driving screw 311, a bevel gear set, a servo motor 315 and an electric push rod 316. The driving screw 311 is provided with a thread on its surface and passes through the upper end of the top frame 32. The driving screw 311 is connected to the upper end of the top frame 32 by threads. The end of the driving screw 311 close to the upper chuck 1 is rotatably connected to the tension sensor 402. The driving screw 311 is hollow inside. The traction rope 304 vertically passes through the driving screw 311. The bevel gear set is installed between the driving screw 311 and the servo motor 315. The servo motor 316 is connected to the upper end of the top frame 32. 15 drives the bevel gear group to drive, and drives the driving screw 311 to rotate through the bevel gear group. The driving screw 311 cooperates with the internal thread of the top frame 32. When the driving screw 311 rotates in the positive direction, the driving screw 311 rotates and moves upward, thereby generating an upward pulling force on the tension sensor 402. The tension sensor 402 pulls the upper clamp 1 upward through the connecting sleeve 401, and the upper clamp 1 generates an upward pulling force on the upper clamp 3. At the same time, the tension sensor 402 monitors the tension between the driving screw 311 and the connecting sleeve 401 to collect experimental data;

[0077] Further, the bevel gear set includes a first bevel gear 313 and a second bevel gear 314 matched with the first bevel gear 313. The first bevel gear 313 is rotatably connected to the upper portion of the top frame 32, and the first bevel gear 313 is slidably matched with the driving screw 311, so that the first bevel gear 313 drives the driving screw 311 to rotate while the driving screw 311 can slide up and down;

[0078] The specific connection mode between the first bevel gear 313 and the driving screw 311 is as follows: a lifting slot 312 is provided on the side of the driving screw 311 along the axial direction; a center hole is provided inside the first bevel gear 313 and the sleeve is arranged on the outside of the driving screw 311; a driving block 318 matching the inside of the lifting slot 312 is arranged in the center hole of the first bevel gear 313; the driving block 318 is slidably arranged inside the lifting slot 312; the second bevel gear 314 is vertically arranged on the side of the first bevel gear 313; the rotating shaft of the servo motor 315 is fixedly connected to the center of the second bevel gear 314; the second bevel gear 314 is driven to rotate by the servo motor 315; the first bevel gear 313 is driven to rotate by the second bevel gear 314; the first bevel gear drives the driving screw 311 to rotate; and the driving screw 311 can move upward or downward while rotating;

[0079] Furthermore, the servo motor 315 is slidably connected to the upper part of the top frame 32, and a fixing plate 317 is installed on the upper part of the top frame 32. The two ends of the electric push rod are fixedly connected to the fixing plate 317 and the servo motor 315 respectively. The electric push rod pushes the servo motor 315 to slide on the top frame 32, so that the servo motor 315 drives the second bevel gear to engage or disengage with the first bevel gear, thereby realizing the switching of the mechanical traction assembly between the traction state and the non-traction state.

[0080] The mechanical traction component controls the traction force on the upper chuck 1, which is easy to control and has high precision, and is conducive to being used as a pressure source in short-term compression creep experiments; in order to overcome the failure of the mechanical traction component due to power outages or circuit failures in long-term compression creep experiments, which affects the progress of the experiment and even causes the failure of the entire long-term compression creep experiment, it can be switched to a gravity traction component with gravity as the pressure source, which has better stability and is conducive to ensuring the stability of long-term compression creep experiments, and the above-mentioned mechanical traction component and the electric push rod 306 of the gravity traction component are electrically connected to the control system of the long-term creep testing machine. Before the experiment, the mode switching between the mechanical traction component and the gravity traction component can be automatically performed through the control system, which is convenient and fast to operate, improves the experimental efficiency, and switches the modules according to the compression creep situation to maximize the accuracy of the compression creep experiment.

[0081] The working principle of the first embodiment is as follows:

[0082] First, the compression assembly is composed of an upper clamp 3, a lower clamp 9, and accessories such as pins connecting them. The upper clamp 3 and the lower clamp 9 are both U-shaped rods and are interlocked. The pin 1 passes through both sides of the open end of the upper clamp 3 and the interior of the upper clamp 1, so that the upper clamp 1 is fixed inside the upper clamp 3. The pin 1 2 is a spring pin, and its spring end automatically pops out to prevent falling off, thereby ensuring the stability of the device.

[0083] Secondly, the extensometer is fixed to the fixture by the extensometer clip 12 or the long pin as a connecting piece, ensuring the synchronous movement of the extensometer and the fixture.

[0084] The sample to be tested is placed between pad 1 6 and pad 2 4, and is connected to the upper chuck 1 through the upper pull rod of the creep testing machine to provide an upward pulling force, and the lower pull rod is connected to the lower chuck 14 to provide a downward pulling force, thereby applying pressure to the sample to be tested placed between pad 1 6 and pad 2 4.

[0085] During the compression creep test, the sample will slowly creep under the action of continuous compression force. At this time, the extensometer 1 8 moves with the connected upper fixture 3, and the extensometer 2 11 moves with the lower fixture 9. This movement causes the length of the extensometer to change, which in turn causes the strain change on the strain gauge, converting the displacement change into an electrical signal.

[0086] These electrical signals are then transmitted to the control system of the permanent creep tester via cables. The control system records and analyzes these electrical signals in real time, converts them into displacement data, and calculates parameters such as creep rate and total deformation, thus realizing the monitoring and evaluation of the creep behavior of the specimen.

[0087] Through this series of steps, the testing machine can accurately monitor the deformation changes of the sample during the compression creep process, providing important data support for material performance research, structural design, etc. At the same time, the tooling abandons the threaded structure and chooses a pin structure instead, avoiding the phenomenon of damage to the test fixture due to excessively high experimental temperature and increasing the service life of the test fixture.

[0088] The working principle of the second embodiment is described in detail as follows:

[0089] The second embodiment improves the design of the first embodiment, mainly for the purpose of realizing the rapid placement and removal of the test sample, while ensuring the coaxiality between the upper clamp 3 and the lower clamp 9 during the experiment, thereby improving the accuracy and efficiency of the compression creep test.

[0090] The main steps are as follows: when the test sample needs to be placed, the lower fixture 9 can slide in the horizontal direction relative to the upper fixture 3 through the design of the coaxial guide rod 21 and the translation guide block 22. When the proximity switch is triggered, the limit block 26 contacts the limit groove 25, indicating that the lower fixture 9 has moved to the topmost position. At this time, the translation guide block 22 enters the translation guide groove 24, the coaxial guide rod 21 is separated from the guide groove, and the lower fixture 9 can slide upward, thereby opening the space between the upper fixture 3 and the lower fixture 9.

[0091] The sample to be tested is placed directly above the pad 1 6, and its positioning groove is aligned with the guide groove of the upper fixture 3. Then, the lower fixture 9 is reset, and the coaxial guide rod 21 and the coaxial guide groove 23 cooperate to ensure that the pad 2 4 is directly above the pad 1 6, and the positioning grooves of the two are kept in the same straight line.

[0092] The upper pull rod and the lower pull rod of the creep tester apply upward pulling force and downward pressure to the upper clamp 1 and the lower clamp 14, and apply compressive force to the sample to be tested between the pad 1 6 and the pad 2 4. In this process, the cooperation of the coaxial guide rod 21 and the coaxial guide groove 23 ensures the coaxial movement of the upper clamp 3 and the lower clamp 9, meeting the coaxiality requirement of the compression creep test.

[0093] After the experiment is completed, the lower clamp 9 moves in the opposite direction through a similar process, that is, the translation guide block 22 leaves the translation guide groove 24, the coaxial guide rod 21 is reconnected with the guide groove, and the lower clamp 9 and the limit block 26 move downward to open the space between the upper clamp 3 and the lower clamp 9, so that the sample to be tested can be easily taken out.

[0094] In order to prevent the connection between the lower tie rod and the lower clamp 14 of the permanent creep tester from affecting the deflection of the lower clamp 9, an active deflection component is installed on the lower clamp 14. The component controls the deflection of the lower clamp 14 by extending and retracting the electric telescopic rod 30, ensuring that the lower clamp 9 can be flexibly deflected to the desired position when installing or removing the test sample, and return to the original position after the operation is completed, so that the lower tie rod applies a stable pressure to the lower clamp 14.

[0095] Through the above steps, the second embodiment realizes the quick and convenient placement and removal of the test sample, while ensuring the accuracy and efficiency of the compression creep test.

[0096] The compression creep test fixture designed in Example 3 is mainly aimed at the problem that the traditional electric and hydraulic drive sources may fail in long-term experiments. By introducing a pressure source switching mechanism, the stability and reliability of the experiment are ensured. Its working principle is as follows:

[0097] One end of the stabilizing frame 31 is fixedly connected to the endurance creep testing machine, and the other end is fixedly connected to the top frame 32. The U-shaped opening end of the top frame 32 is fixedly connected to the upper end of the stabilizing frame 31, thereby ensuring the stability of the entire tooling during the experiment.

[0098] The compression assembly is slidably disposed inside the stabilizing frame 31, and the upper clamp 1 and the lower clamp 14 are respectively provided with a pressure switching assembly. The pressure switching assembly includes a gravity traction assembly and a mechanical traction assembly.

[0099] The gravity traction assembly generates a pulling force on the traction rope 304 through the weight and the weight plate 305. One end of the traction rope 304 is connected to the upper clamp 1, and the other end is fixedly connected to the weight plate 305. The first pulley 302 is arranged above the upper clamp 1, and the second pulley 303 is arranged on the outer side of the upper end of the top frame 32, so that the top frame 32 does not affect the natural falling of the weight plate 305, and at the same time, the traction rope 304 generates a vertical upward pulling force on the upper clamp 1 through the second pulley 303.

[0100] The mechanical traction assembly is connected to the upper clamp 1 through the tension sensor 402. When the driving screw 311 rotates, the driving screw 311 is driven to move upward through the bevel gear set and the servo motor 315, and an upward pulling force is generated on the upper clamp 1.

[0101] By providing a connection assembly, the traction rope 304 and the tension sensor 402 can be rotatably connected to achieve monitoring and adjustment of the traction force.

[0102] When the experiment needs to switch the pressure source, the electric push rod 306 can be retracted to drive the support plate 307 to lift the weight plate 305, so that the weight and the weight plate 305 do not produce a pulling force on the traction rope 304, thereby switching to a mechanical traction component. Conversely, when the experiment needs to use gravity as the pressure source, it can be automatically switched to a gravity traction component through the control system.

[0103] The electric push rod 1 306 and the electric push rod 2 316 are both electrically connected to the control system of the endurance creep testing machine, so as to automatically switch the pressure source mode before the experiment and improve the experimental efficiency.

[0104] The compression creep test fixture of the third embodiment achieves stability and reliability in long-term and short-term experiments through the pressure source switching mechanism, providing a strong guarantee for the experiment.

[0105] A test method for a compression creep test fixture:

[0106] S1. Install the pads 6 and 4 on the upper fixture 3 and the lower fixture 9 respectively, place the test sample between the pads 6 and 4, and fix the extensometer and the fixture pin to achieve synchronous movement;

[0107] S2. The upper clamp 3 and the lower clamp 9 are buckled with each other, and the upper clamp 3 and the lower clamp 9 are respectively connected to the corresponding upper clamp 1 and the lower clamp 14 through the pin structure to ensure its stability;

[0108] S3. The upper chuck 1 and the lower chuck 14 are connected by an upper pull rod and a lower pull rod, respectively, to apply an upward pulling force and a downward pressure;

[0109] S4. The upper chuck 1 and the lower chuck 14 are respectively connected to a pressure source switching mechanism. During the experiment, as needed, the pressure source is switched by the electric push rod to achieve gravity traction or mechanical traction;

[0110] S5. Ensure that the coaxial guide rod 21 cooperates with the coaxial guide groove 23 to ensure the coaxiality of the upper fixture 3 and the lower fixture 9. When the limit block 26 enters the limit groove 25, the proximity switch is triggered. When the active offset component works normally, the lower fixture 9 is pushed to offset relative to the upper fixture 3, so that the test sample can be quickly and conveniently placed in and taken out.

Claims

1. A compression creep test tool, comprising a compression component and a creep measurement component; the compression component cooperates with a permanent creep tester to compress a sample to be tested, characterized in that: The compression assembly comprises an upper clamp (3) and a lower clamp (9), both of which are U-shaped rods. The upper clamp (3) and the lower clamp (9) are interlocked with each other, the open end of the upper clamp (3) is connected to an upper clamp (1) via a pin, and the open end of the lower clamp (9) is connected to a lower clamp (14) via a pin; two groups of creep measurement assemblies are provided and are respectively fixed to the upper clamp (3) or the lower clamp (9) by plugging through pins.

2. A compression creep test fixture according to claim 1, characterized in that: Pin holes are provided on both sides of the open end of the upper clamp (3), and a pin (2) is installed between the upper clamp (3) and the upper chuck (1). The pin (2) passes through both sides of the open end of the upper clamp (3) and the interior of the upper chuck (1), and the side surface of the upper chuck (1) is in contact with the inner side of the upper clamp (3); the connection method between the lower chuck (14) and the lower clamp (9) is the same as the connection method between the upper chuck (1) and the upper clamp (3).

3. A compression creep test fixture according to claim 1, characterized in that: The creep measurement assembly comprises two extensometers 1 (8) and two extensometers 2 (11), the two extensometers 1 (8) being connected to one end of the upper fixture (3) away from the upper clamp (1), and the two extensometers 2 (11) being connected to one end of the lower fixture (9) away from the lower clamp (14); A cushion block 1 (6) is installed on the inner side of one end of the upper clamp (3) away from the upper clamp (1), and a cushion block 2 (4) is installed on one end of the lower clamp (9) away from the lower clamp (14). Positioning grooves are provided inside the cushion block 1 (6) and the cushion block 2 (4). The positioning grooves of the cushion block 1 (6) and the cushion block 2 (4) are used for placing the sample to be tested. The two extensometers (8) are located on both sides of the upper clamp (3), an extensometer clip (12) is arranged between the two extensometers (8), the extensometer clip (12) is located on the outer side of one end of the upper clamp (3) close to the cushion block (6), the cushion block (6), the side of the upper clamp (3) close to the extensometer clip (12) and the middle of the extensometer clip (12) are coaxially provided with insertion holes, a pin (13) is arranged inside the pin hole, the pin (13) passes through the insertion holes of the cushion block (6), the upper clamp (3) and the extensometer clip (12), so as to connect and fix the cushion block (6), the upper clamp (3) and the extensometer clip (12), the two ends of the extensometer clip (12) are provided with clamping holes (7), one end of the extensometer (8) is provided with a mounting hole, and a positioning pin (5) is inserted between the mounting hole and the clamping hole (7); An axial hole is coaxially provided between the lower clamp (9) and the second cushion block (4), and a long pin is inserted into the axial hole. The long pin passes through the interior of the lower clamp (9) and the second cushion block (4), and the two ends of the long pin extend to the outside of the two sides of the lower clamp (9). A clamping groove (10) is provided at the end of the long pin located outside the lower clamp (9), and the end of the extensometer second (11) and the extensometer first (8) are also provided with a mounting hole.

4. A compression creep test fixture according to claim 3, characterized in that: The distance between the inner walls on both sides of the upper fixture (3) is greater than the width of the lower fixture (9). When the compression creep test is in working state, the lower fixture (9) is located in the middle of the upper fixture (3). The positioning grooves of the engaging pad block 1 (6) and the pad block 2 (4) are circular and located on the same axis. The pad block 1 (6) moves with the upper fixture (3), and the pad block 2 (4) moves with the lower fixture (9). The upper clamp (3) is provided with a coaxial guide groove (23) at one end close to the pad (6), and a translation guide groove (24) is connected to one side of the coaxial guide groove (23). The translation guide groove (24) is perpendicular to the coaxial guide groove (23). A coaxial guide rod (21) is fixedly connected to the inner side of the lower clamp (9). The outer shape of the coaxial guide rod (21) is adapted to the inner part of the guide groove. A translation guide block (22) is fixedly connected to the inner side of the lower clamp (9) close to the lower clamp (14). The translation guide block (22) can slide along the inside of the coaxial guide groove (23). When it moves to the position where the coaxial guide groove (23) and the translation guide groove (24) are connected, the coaxial guide rod (21) is separated from the inside of the guide groove, and the translation guide block (22) can slide along the inside of the translation guide groove (24). A limit block (26) is arranged at one end of the lower clamp (9) close to the upper clamp (1); a limit groove (25) adapted to the limit block (26) is provided on one side of the upper clamp (1) close to the limit block (26); the limit groove (25) and the translation guide groove (24) are located on the same side of the coaxial guide groove (23) and have the same length; a proximity switch 1 is installed on the top of the limit block (26); a proximity switch 2 is arranged inside the end of the translation guide groove (24) away from the coaxial guide groove (23); and a proximity switch 3 is arranged inside the side of the translation guide block (22) away from the translation guide groove (24); The lower clamp (14) is provided with an active offset component. The lower clamp (14) comprises a clamp block (27) and a connecting shaft (28). The connecting shaft (28) and the clamp block (27) are movably connected. The lower pull rod of the endurance creep tester is fixedly connected to the connecting shaft (28) of the lower clamp (14). The clamp block (27) is connected to the end of the lower clamp (9). A sliding groove is provided at one end of the clamp block (27) close to the connecting shaft (28). A displacement slide is slidably connected inside the sliding groove. The connecting shaft (28) is fixedly connected to the middle part of the side of the displacement slide away from the lower clamp (9). A mounting seat (29) is provided at one end of the displacement slide. An electric telescopic rod (30) is fixedly connected inside the mounting seat (29). The telescopic end of the electric telescopic rod (30) is fixedly connected to the side of the clamp block (27). The circuit of the electric telescopic rod (30) is connected to the control system of the endurance creep tester.

5. The compression creep test fixture according to claim 1, characterized in that: It also includes a stabilizing frame (31) and a pressure source switching mechanism. One end of the stabilizing frame (31) is fixedly connected to the permanent creep testing machine. The compression assembly is slidably arranged inside the stabilizing frame (31). The upper chuck (1) and the lower chuck (14) in the compression assembly are respectively provided with a pressure switching assembly. The pressure switching assembly includes a gravity traction assembly and a mechanical traction assembly.

6. A compression creep test fixture according to claim 5, characterized in that: One end of the stabilizing frame (31) close to the upper clamp (1) is fixedly connected to a top frame (32); the top frame (32) is U-shaped, and its U-shaped open end is fixedly connected to the upper end of the stabilizing frame (31); and a gravity traction component and a mechanical traction component are mounted on the top frame (32).

7. A compression creep test fixture according to claim 6, characterized in that: The gravity traction assembly comprises a pulley frame (301), on which a first pulley (302) and a second pulley (303) are mounted, and a traction rope (304) is also arranged on the pulley frame (301), the traction rope (304) passes through the upper parts of the first pulley (302) and the second pulley (303), and both ends of the traction rope (304) are vertically downward, one end of the traction rope (304) is connected to the upper clamp (1), and the other end of the traction rope (304) is fixedly connected to a weight plate (305), and the weight plate (305) is used for placing weights; the first pulley (302) is arranged above the upper clamp (1), and the second pulley (303) is arranged on the outer side of the upper end of the top frame (32).

8. A compression creep test fixture according to claim 7, characterized in that: A connecting assembly is provided between the traction rope (304) and the upper clamp (1), and the connecting assembly comprises a connecting sleeve (401) and a tension sensor (402). One end of the tension sensor (402) is fixedly connected to the connecting sleeve (401). The connecting sleeve (401) is sleeved on the outside of the upper end of the traction head and is plugged and fixed by a latch (403). A knob (308) for rotational connection is provided between the traction rope (304) and the pressure sensor. An electric push rod (306) is fixedly installed on the outer side of one end of the pulley frame (301) close to the second pulley (303). The telescopic end of the electric push rod (306) is fixedly connected to a support plate (307) adapted to the bottom of the weight plate (305), and the support plate (307) is provided below the weight plate (305).

9. The compression creep test fixture according to claim 5, characterized in that: The mechanical traction assembly comprises a driving screw (311), a bevel gear set, a servo motor (315) and a second electric push rod (316). The driving screw (311) is provided with a thread on its surface and passes through the interior of the upper end of the top frame (32). The driving screw (311) is threadedly connected to the interior of the upper end of the top frame (32). One end of the driving screw (311) close to the upper chuck (1) is rotatably connected to the tension sensor (402). The interior of the driving screw (311) is hollow. The traction rope (304) vertically passes through the interior of the driving screw (311). The bevel gear set is installed between the driving screw (311) and the servo motor (315). The servo motor (315) drives the bevel gear set to transmit. The bevel gear set comprises a first bevel gear (313 ) and a second bevel gear (314) matched with the first bevel gear (313), the first bevel gear (313) is rotatably connected to the upper part of the top frame (32), and the first bevel gear (313) and the driving screw (311) are slidably matched; the second bevel gear (314) is vertically arranged on the side of the first bevel gear (313), and the rotating shaft of the servo motor (315) is fixedly connected to the center of the second bevel gear (314); the servo motor (315) is slidably connected to the upper part of the top frame (32), and a fixing plate (317) is installed on the upper part of the top frame (32), the two ends of the electric push rod are respectively fixedly connected to the fixing plate (317) and the servo motor (315), and the electric push rod pushes the servo motor (315) to slide on the top frame (32).

10. A test method for a compression creep test fixture, implemented based on a compression creep test fixture according to any one of claims 1 to 15, characterized in that: S1. Install the pad 1 (6) and the pad 2 (4) on the upper fixture (3) and the lower fixture (9) respectively, place the test sample between the pad 1 (6) and the pad 2 (4), and use the extensometer to connect and fix it with the fixture pin to achieve synchronous movement; S2. The upper clamp (3) and the lower clamp (9) are buckled together, and the upper clamp (3) and the lower clamp (9) are respectively connected to the corresponding upper clamp (1) and the lower clamp (14) through a pin structure to ensure their stability; S3. The upper chuck (1) and the lower chuck (14) are connected respectively by an upper pull rod and a lower pull rod to apply an upward pulling force and a downward pressure; S4. The upper chuck (1) and the lower chuck (14) are respectively connected to a pressure source switching mechanism. During the experiment, as needed, the pressure source is switched by the electric push rod to achieve gravity traction or mechanical traction; S5. Ensure that the coaxial guide rod (21) cooperates with the coaxial guide groove (23) to ensure the coaxiality of the upper fixture (3) and the lower fixture (9). When the limit block (26) enters the limit groove (25), the proximity switch is triggered. When the active offset component works normally, the lower fixture (9) is pushed to offset relative to the upper fixture (3) so that the test sample can be quickly and conveniently placed in and taken out.

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