Pseudo-static test apparatus

Abstract

The application belongs to the technical field of static test, and relates to a quasi-static test device. The device comprises a support frame, two first hydraulic push rods symmetrically arranged on the support frame, a sliding block, a pressure frame slidably connected to the sliding block, a base fixed to the lower part of the support frame, connecting frames symmetrically arranged and slidably connected to the base, a counterforce frame rotatably connected to the connecting frames, torsional springs fixed between the counterforce frame and the connecting frames, and extrusion frames symmetrically arranged and slidably connected to the base. The positions of the two extrusion frames are adjusted to determine the position of the counterforce frame for supporting the sample, so that the end-fixed sample and the end-hinged sample are simulated. The height of the extrusion frame is changed to adjust the compression degree and the inclination degree of the counterforce frame during force receiving, so that the quasi-static test of the sample under various boundary conditions is realized, and the diversity of test results is improved.

Description

Technical Field

[0001] This invention relates to the field of static testing technology, and more particularly to a quasi-static testing device. Background Technology

[0002] Quasi-static testing, also known as low-cycle cyclic loading testing, is a key method in structural engineering and materials science for evaluating the mechanical properties of materials, components, or structural nodes under low-frequency cyclic loading such as simulated earthquakes. The accuracy of the test results highly depends on whether the test equipment can accurately simulate the boundary conditions and stress state of the specimen in actual working conditions. Existing quasi-static testing equipment usually fixes the specimen directly when applying loads, which means that the stress analysis of the specimen under fixed conditions can only be achieved in the simulation of the specimen boundary conditions. However, in real life, specimens have various connection methods such as fixed connection, hinged connection, and elastic support, and the connection strength of each connection method is different. This leads to the test conditions being out of touch with engineering reality, and the test results are singular and cannot fully reflect the true mechanical behavior of the specimen under different constraints. Summary of the Invention

[0003] In order to overcome the shortcomings mentioned in the background art, the present invention provides a quasi-static testing device.

[0004] The technical implementation of the present invention is as follows: a quasi-static testing device includes a support frame, on which two symmetrically distributed first hydraulic push rods are mounted. The first hydraulic push rods are connected to an external hydraulic system, which is equipped with a pressure sensor. A sliding block is fixedly connected to the telescopic part of the first hydraulic push rod. A pressure frame is slidably connected to the sliding block. The two pressure frames are in contact with each other. A base is fixedly connected to the lower part of the support frame. A symmetrically distributed connecting frame is slidably connected to the base. The symmetrically distributed connecting frames are rotatably connected to a reaction frame. A torsion spring is fixedly connected between the reaction frame and the connecting frame. A symmetrically distributed extrusion frame is slidably connected to the base. The extrusion frame is used to extrude the reaction frame. A symmetrically distributed first motor is mounted on the support frame. The output shaft of the first motor is fixedly connected to a first threaded rod rotatably connected to the support frame. The first threaded rod is threadedly connected to the adjacent extrusion frame.

[0005] As a preferred embodiment of the present invention, an elastic pad is provided between the base and the reaction frame, the base is equipped with symmetrically distributed hydraulic telescopic rods, the connecting frame is used to compress the telescopic parts of the symmetrically distributed hydraulic telescopic rods, and the hydraulic telescopic rods are connected to an external hydraulic system.

[0006] As a preferred embodiment of the present invention, one of the pressure frames is provided with an arc-shaped portion, and the other pressure frame is provided with an arc-shaped groove, wherein the arc-shaped portion slides within the arc-shaped groove.

[0007] As a preferred embodiment of the present invention, the rotation axis of the arc-shaped portion is located on the lower side of the contact surfaces of the two pressure frames.

[0008] As a preferred embodiment of the present invention, the pressure frame is slidably connected with a plurality of weights distributed at intervals.

[0009] As a preferred embodiment of the present invention, the pressure frame is equipped with a second motor, and the output shaft of the second motor is fixedly connected to a plurality of spaced-apart extrusion blocks via a rotating shaft. The number of extrusion blocks is the same as the number of weights, and the extrusion blocks are used to limit the movement of adjacent weights.

[0010] As a preferred embodiment of the present invention, the contact surfaces of the two pressure frames are used as projection surfaces, the projection of the rotation axis on the output shaft of the second motor is used as the vertex, and the included angle between the projections of the central axes of adjacent extrusion blocks is 90°.

[0011] As a preferred embodiment of the present invention, the reaction frame is slidably connected to a reaction plate, and the reaction plate is provided with a groove.

[0012] As a preferred embodiment of the present invention, one of the extrusion frames is slidably connected to a laser emitter, and the other extrusion frame is slidably connected to a laser receiver. The laser receiver is used to receive signals from the laser emitter. Both the laser emitter and the laser receiver are rotatably connected to a second threaded rod, and the second threaded rod is threadedly connected to the adjacent extrusion frame.

[0013] As a preferred embodiment of the present invention, a second hydraulic push rod is installed inside the base, and a compression plate is fixedly connected to the telescopic part of the second hydraulic push rod. The compression plate is used to compress the elastic pad.

[0014] In summary, this application includes the following beneficial technical effects: The present invention adjusts the positions of the two extrusion frames to determine the position where the reaction frame supports the sample, simulating samples with fixed and hinged ends. Furthermore, by changing the height of the extrusion frames, the compressibility and tilt of the reaction frame during the stress process are adjusted, enabling quasi-static tests of the sample under various boundary conditions and improving the diversity of test results. When distributed and concentrated loads need to be applied to the sample surface, the positions of multiple extrusion blocks are adjusted to control the positions of multiple weights, thereby increasing the number of stress points on the sample during the test and improving the diversity of quasi-static tests. After the sample test is completed, the deformation of the sample surface is monitored using a laser emitter and laser receiver. Moreover, when testing samples of different thicknesses, the height of the laser emitter and laser receiver is adjusted by rotating the second threaded rod, increasing the applicability of the testing device. When conducting quasi-static tests on samples connected by elastic supports, the extrusion pressure generated by the extrusion plate on the elastic pad is adjusted, thereby adjusting the elastic support force provided by the elastic pad to the sample through the reaction frame, adapting to the elastic support strength experienced by different samples in actual use and improving the accuracy of test results. Attached Figure Description

[0015] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0016] Figure 2 This is a three-dimensional structural diagram of the pressure frame of the present invention;

[0017] Figure 3 This is a three-dimensional structural schematic diagram of the reaction frame of the present invention;

[0018] Figure 4 This is a three-dimensional structural diagram of the weight block of the present invention;

[0019] Figure 5 This is an exploded view of the three-dimensional structure of the extrusion block of the present invention;

[0020] Figure 6 This is a three-dimensional structural diagram of the reaction plate of the present invention.

[0021] In the attached figures, the following are the reference numerals: 1: support frame, 2: first hydraulic push rod, 3: sliding block, 4: pressure frame, 5: base, 6: reaction frame, 601: connecting frame, 7: extrusion frame, 8: first motor, 9: first threaded rod, 10: elastic pad, 11: hydraulic telescopic rod, 12: arc-shaped part, 13: arc-shaped groove, 14: weight, 15: second motor, 16: extrusion block, 17: reaction plate, 18: groove, 19: laser emitter, 20: laser receiver, 21: second threaded rod, 22: second hydraulic push rod, 23: extrusion plate. Detailed Implementation

[0022] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but this does not limit the scope of protection and application of the present invention.

[0023] Example 1

[0024] In real life, samples have various connection methods such as fixed connection, hinged connection and elastic support, and the connection strength of each connection method is different. This will lead to the disconnect between the test conditions and the actual engineering, and the test results will be singular and unable to fully reflect the real mechanical behavior of the specimen under different constraints.

[0025] A quasi-static testing device, referring to Figures 1-5 As shown, the system includes a support frame 1, on which a control terminal (not shown) is mounted. The support frame 1 also has two symmetrically distributed first hydraulic push rods 2, both electrically connected to the control terminal. The first hydraulic push rods 2 are connected to an external hydraulic system, which is equipped with a pressure sensor electrically connected to the control terminal. The pressure sensor monitors the applied load and displacement of the telescopic portion of the first hydraulic push rod 2 to monitor changes in the load and displacement of the sample (i.e., the object being compressed). A sliding block 3 is fixedly connected to the telescopic portion of the first hydraulic push rod 2, and a pressure frame 4 is slidably connected to the sliding block 3. The two pressure frames 4 are in contact and apply a load to the sample. A base 5 is fixedly connected to the lower part of the support frame 1, and two symmetrically distributed connecting frames 601 are slidably connected to the base 5. The two connecting frames 601 are rotatably connected to a reaction frame 6, which supports the sample and applies boundary conditions to it. The reaction frame 6 is connected to the connecting... A torsion spring is fixed between the connecting frames 601. The base 5 is slidably connected to two symmetrically distributed extrusion frames 7. The extrusion frames 7 are used to extrude the reaction frame 6 to adjust the height position of the reaction frame 6, thereby adjusting the height difference between the two sides of the reaction frame 6. The different connection strengths at both ends of the sample are simulated, and the connection methods (fixed connection, hinged connection) at both ends of the sample are simulated. The support frame 1 is equipped with two symmetrically distributed first motors 8. Both first motors 8 are electrically connected to the control terminal. The output shaft of the first motor 8 is fixedly connected to a first threaded rod 9 that is rotatably connected to the support frame 1. The first threaded rod 9 is threadedly connected to the adjacent extrusion frame 7. By rotating the first threaded rod 9, the position of the adjacent extrusion frame 7 is adjusted. The right pressure frame 4 is provided with an arc-shaped part 12, and the left pressure frame 4 is provided with an arc-shaped groove 13. The arc-shaped part 12 slides in the arc-shaped groove 13. When the two pressure frames 4 rotate relative to each other, the rotation axis of the arc-shaped part 12 is located on the lower side of the contact surface of the two pressure frames 4.

[0026] Reference Figure 2 and Figure 3As shown, an elastic pad 10 is provided between the base 5 and the reaction frame 6. The base 5 is equipped with two hydraulic telescopic rods 11 symmetrically distributed front and rear. The connecting frame 601 is used to compress the telescopic parts of the two hydraulic telescopic rods 11. The hydraulic telescopic rods 11 are connected to the external hydraulic system. When the two compression frames 7 are no longer supporting the reaction frame 6, and the connecting frame 601 moves downward to compress the telescopic parts of the hydraulic telescopic rods 11, the elastic pad 10 supports the reaction frame 6. When the elastic pad 10 deforms, the telescopic parts of the hydraulic telescopic rods 11 move downward and squeeze the hydraulic oil inside into the external hydraulic system. A quasi-static test is performed on the strength of the sample under elastic support.

[0027] The specific working principle is as follows:

[0028] When this device is needed to perform a quasi-static test on a sample, the operator places the sample on the reaction frame 6 and then activates the two first hydraulic push rods 2 through the control terminal. The telescopic part of the first hydraulic push rod 2 drives the pressure frame 4 to move downward through the sliding block 3. The pressure frame 4 applies pressure to the sample, and the reaction frame 6 provides a reaction force to the sample. The pressure sensor monitors the applied load and displacement of the telescopic part on the first hydraulic push rod 2 to monitor the changes in the load and displacement of the sample (i.e., the object being squeezed).

[0029] Before conducting the quasi-static test on the sample, if the sample is fixed at both ends during actual use, the two first motors 8 are turned on by the control terminal. The output shaft of the first motor 8 drives the first threaded rod 9 to rotate, causing the two extrusion frames 7 to move in opposite directions. The two extrusion frames 7 jointly support the reaction frame 6. Then, the two first motors 8 are turned off by the control terminal to conduct the quasi-static test on the sample in the fixed state. After the test is completed, the telescopic parts of the two first hydraulic push rods 2 and the output shafts of the two first motors 8 are reset by the control terminal, the two first hydraulic push rods 2 are turned off, and the sample after the test is removed.

[0030] If the sample is hinged at one end during actual use, the left first motor 8 is activated via the control terminal. The output shaft of the left first motor 8 drives the adjacent first threaded rod 9 to rotate. The left extrusion frame 7 supports the reaction frame 6, while the right extrusion frame 7 does not contact the reaction frame 6. Both first motors 8 are deactivated via the control terminal. When the two pressure frames 4 apply pressure to the sample, the left side of the reaction frame 6 is supported by the extrusion frame 7, and the right side of the reaction frame 6 is supported by the elastic pad 10. The two pressure frames 4 compress the sample, causing deformation on the right side of the elastic pad 10. The right pressure frame 4 moves downward a greater distance than the left pressure frame 4, causing the two pressure frames 4 to rotate relative to each other. The right sliding block 3 then interacts with the adjacent pressure... The frame 4 slides relative to each other, and the right pressure frame 4 rotates, so that the left end of the sample is clamped by the reaction frame 6 and the left pressure frame 4. The right side of the sample is continuously compressed and bends. The arc-shaped part 12 slides out of the arc-shaped groove 13, the reaction frame 6 twists, the torsion spring of the reaction frame 6 stores force, the elastic pad 10 is compressed, and the applied load and displacement of the telescopic part on the two first hydraulic push rods 2 are different. The operator performs a pseudo-static test on the sample in the hinged state. After the test is completed, the telescopic part of the two first hydraulic push rods 2 and the output shaft of the first motor 8 are reset through the control terminal. The torsion spring of the reaction frame 6 rebounds and drives it to reset. The elastic pad 10 rebounds and resets. The two first hydraulic push rods 2 are closed and the sample after the test is removed.

[0031] When a quasi-static test is required on a sample under elastic support, the operator activates two first motors 8 via a control terminal. The output shafts of the first motors 8 drive the extrusion frame 7 to move via the first threaded rod 9, causing the two extrusion frames 7 to move in opposite directions. Neither of the two extrusion frames 7 supports the reaction frame 6. During the sample compression process, the reaction frame 6 is supported by the elastic pad 10. When the elastic pad 10 deforms, the telescopic part of the hydraulic telescopic rod 11 moves downward and squeezes the hydraulic oil inside into the external hydraulic system to monitor the deformation of the elastic pad 10. A quasi-static test is then conducted on the sample's strength under elastic support. After the test is completed, the telescopic parts of the two first hydraulic push rods 2 and the output shafts of the two first motors 8 are reset via the control terminal. The elastic pad 10 rebounds and resets, and the hydraulic oil in the external hydraulic system is injected back, causing the hydraulic telescopic rod 11 to reset. The two first hydraulic push rods 2 are then closed, and the tested sample is removed.

[0032] When conducting quasi-static tests on samples, the positions of the two compression frames 7 are adjusted to determine the position where the reaction frame 6 supports the sample, simulating samples with fixed ends and hinged ends. Furthermore, by adjusting the position of the compression frames 7, the degree of compression and inclination of the reaction frame 6 during the force process can be adjusted, thereby realizing quasi-static tests on samples under various boundary conditions and improving the diversity of test results.

[0033] Example 2

[0034] Based on Example 1, referring to Figures 3-5 As shown, the pressure frame 4 is slidably connected to several spaced weights 14. The pressure frame 4 is equipped with a second motor 15 electrically connected to a control terminal. The output shaft of the second motor 15 is fixedly connected to several spaced extrusion blocks 16 via a rotating shaft. The number of extrusion blocks 16 is the same as the number of weights 14. In the figure, taking an example where each output shaft of the second motor 15 has three extrusion blocks 16, initially, none of the three extrusion blocks 16 are in contact with their corresponding weights 14. After the second motor 15 rotates 90°, one of the extrusion blocks 16 rotates to contact its corresponding weight 14, thus limiting the movement of the adjacent weights 14. The reaction frame 6 is slidably connected to a reaction plate 17, which has grooves 18. When a uniformly distributed load needs to be applied to the sample surface, all... None of the extrusion blocks 16 extrude the corresponding weight blocks 14. The sample is located on the reaction plate 17. The pressure frame 4 drives all the weight blocks 14 on it to move downward to extrude the sample. The weight blocks 14 extrude the sample and move upward. The pressure frame 4 and all the weight blocks 14 on it apply a uniformly distributed load to the sample surface. The contact surface of the two pressure frames 4 is the projection surface, and the projection of the rotation axis on the output shaft of the second motor 15 is the vertex. The angle between the projections of the central axes of adjacent extrusion blocks 16 is 90°, and the angle between the projections of the central axes of the two extrusion blocks 16 that are furthest apart is 180°. When all the extrusion blocks 16 rotate to the point where their lowest side is flush with the upper side of the weight block 14 at its limit position, after all the weight blocks 14 move upward to their limit state, the lower side of the weight block 14 is coplanar with the lower side of the pressure frame 4.

[0035] When a concentrated load needs to be applied to a specific point on the sample surface, slide the reaction plate 17 backward so that the groove 18 is below the pressure frame 4, place the sample above the groove 18, and turn on the output shaft of the second motor 15 through the control terminal. The output shaft of the second motor 15 drives all the extrusion blocks 16 on it to rotate through the rotating shaft, so that one of the extrusion blocks 16 rotates to contact the corresponding weight block 14. The extrusion block 16 applies a concentrated load to the sample until the sample bends into the groove 18, thereby performing various force analyses on the sample and improving the diversity of quasi-static tests. When the device is no longer in use, turn off the second motor 15 through the control terminal.

[0036] Example 3

[0037] Based on Example 2, referring to Figure 3As shown, one extrusion frame 7 is slidably connected to a laser emitter 19 electrically connected to a control terminal, and the other extrusion frame 7 is slidably connected to a laser receiver 20 electrically connected to a control terminal. The laser receiver 20 is used to receive signals from the laser emitter 19. Both the laser emitter 19 and the laser receiver 20 are rotatably connected to a second threaded rod 21, which is threadedly connected to the adjacent extrusion frame 7. Before the sample is tested, the laser emitter 19 and the laser receiver 20 are turned on through the control terminal to correct the flatness of the sample's upper surface. After the sample is compressed, the flatness of the sample surface is detected through the laser emitter 19 and the laser receiver 20. Furthermore, when it is necessary to test samples of different thicknesses, the heights of the laser emitter 19 and the laser receiver 20 are adjusted by rotating the two second threaded rods 21 to improve the applicability of this testing device. After the test is completed, the laser emitter 19 and the laser receiver 20 are turned off through the control terminal.

[0038] Example 4

[0039] Based on Example 3, referring to Figure 3 and Figure 6 As shown, a second hydraulic push rod 22 electrically connected to the control terminal is installed inside the base 5. The telescopic part of the second hydraulic push rod 22 is fixedly connected to a compression plate 23. The compression plate 23 is used to compress the elastic pad 10. The telescopic part of the second hydraulic push rod 22 is used to drive the compression plate 23 to move, so as to adjust the compression force generated by the compression plate 23 on the elastic pad 10, thereby adjusting the elastic support force that the elastic pad 10 brings to the sample through the reaction frame 6, so as to adapt to the elastic support strength of different samples in actual use and improve the accuracy of the test results.

[0040] The technical principles of the embodiments of the present invention have been described above with reference to specific examples. These descriptions are merely for explaining the principles of the embodiments of the present invention and should not be construed as limiting the scope of protection of the embodiments of the present invention in any way. Based on the explanation herein, those skilled in the art can conceive of other specific embodiments of the present invention without creative effort, and these embodiments will all fall within the scope of protection of the embodiments of the present invention.

Claims

1. A quasi-static testing device, comprising a support frame (1), wherein the support frame (1) is equipped with two symmetrically distributed first hydraulic push rods (2), the first hydraulic push rods (2) being connected to an external hydraulic system, the external hydraulic system being equipped with a pressure sensor, and a sliding block (3) being fixedly connected to the telescopic portion of the first hydraulic push rods (2), characterized in that, The sliding block (3) is slidably connected to the pressure frame (4), and the two pressure frames (4) are in contact. The lower part of the support frame (1) is fixedly connected to the base (5). The base (5) is slidably connected to the symmetrically distributed connecting frame (601). The symmetrically distributed connecting frame (601) is rotatably connected to the reaction frame (6). The reaction frame (6) and the connecting frame (601) are fixedly connected to the torsion spring. The base (5) is slidably connected to the symmetrically distributed extrusion frame (7). The extrusion frame (7) is used to extrude the reaction frame (6) to adjust the height position of the reaction frame (6), thereby adjusting the height difference on both sides of the reaction frame (6). The different connection strengths at both ends of the sample are simulated, and the connection methods of the fixed connection and the hinge connection at both ends of the sample are simulated. The support frame (1) is equipped with a symmetrically distributed first motor (8). The output shaft of the first motor (8) is fixedly connected to the first threaded rod (9) which is rotatably connected to the support frame (1). The first threaded rod (9) is threadedly connected to the adjacent extrusion frame (7). An elastic pad (10) is provided between the base (5) and the reaction frame (6). The base (5) is equipped with symmetrically distributed hydraulic telescopic rods (11). The connecting frame (601) is used to squeeze the telescopic parts of the symmetrically distributed hydraulic telescopic rods (11). The hydraulic telescopic rods (11) are connected to an external hydraulic system. One of the pressure frames (4) is provided with an arc-shaped part (12), and the other pressure frame (4) is provided with an arc-shaped groove (13), and the arc-shaped part (12) slides in the arc-shaped groove (13); The rotation axis of the arc-shaped part (12) is located on the lower side of the contact surface of the two pressure frames (4).

2. The quasi-static testing device according to claim 1, characterized in that, The pressure frame (4) is slidably connected to several weights (14) distributed at intervals.

3. The quasi-static testing device according to claim 2, characterized in that, The pressure frame (4) is equipped with a second motor (15). The output shaft of the second motor (15) is fixed with a plurality of spaced extrusion blocks (16) through a rotating shaft. The number of extrusion blocks (16) is the same as the number of weights (14). The extrusion blocks (16) are used to limit the movement of adjacent weights (14).

4. The quasi-static testing device according to claim 3, characterized in that, With the contact surfaces of the two pressure frames (4) as the projection surfaces, the projection of the rotation axis on the output shaft of the second motor (15) as the vertex, and the included angle between the projections of the central axes of the adjacent extrusion blocks (16) is 90°.

5. The quasi-static testing device according to claim 1, characterized in that, The reaction frame (6) is slidably connected to a reaction plate (17), and the reaction plate (17) is provided with a groove (18).

6. The quasi-static testing device according to claim 1, characterized in that, One of the extrusion frames (7) is slidably connected to a laser emitter (19), and the other extrusion frame (7) is slidably connected to a laser receiver (20). The laser receiver (20) is used to receive the signal from the laser emitter (19). Both the laser emitter (19) and the laser receiver (20) are rotatably connected to a second threaded rod (21). The second threaded rod (21) is threadedly connected to the adjacent extrusion frame (7).

7. The quasi-static testing device according to claim 1, characterized in that, A second hydraulic push rod (22) is installed inside the base (5). The telescopic part of the second hydraulic push rod (22) is fixedly connected to a pressing plate (23). The pressing plate (23) is used to press the elastic pad (10).

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