Pulse current auxiliary tension compression self-centering test device

Abstract

The invention provides a pulse current assisted tensile compression self-centering test device, and belongs to the technical field of material mechanics tensile and compression performance test equipment.The pulse current assisted tensile compression self-centering test device comprises a testing machine, a clamping fixture, a compression mechanism, a clamping mechanism, an electrode plate, a buckling-restrained mechanism and a centering clamping mechanism, and the clamping fixture is connected to the testing machine and clamps and fixes a sample; the clamping mechanism is pulled to move through the compression mechanism, and the clamping mechanism can clamp and fix the electrode plate, so that the electrode plate can provide pulse current for the sample; the buckling-restrained mechanism slidably abuts against the sample and can prevent the sample from buckling, and the centering clamping mechanism can keep the sample to be centered in the length direction. The pulse current-assisted tensile compression self-centering test device provided by the invention can realize self-centering of a sample, and ensures the safety and accuracy of a tensile and compression test process, thereby promoting wide application of a pulse current-assisted tensile and compression test technology in material mechanical property tests.

Description

Technical Field

[0001] The present invention belongs to the technical field of testing equipment for tensile and compressive properties of materials mechanics, and more specifically, relates to a pulse current-assisted tensile and compressive self-aligning test device. Background Art

[0002] In the field of testing the mechanical properties of materials, pulse current-assisted tensile and compressive tests are important means to evaluate the mechanical properties of materials (such as strength, ductility, etc.). Its core value lies in the coordination of electrical energy and mechanical energy to break through the inherent deformation limit of materials and achieve the advanced manufacturing goal of "lighter, stronger, and more efficient". With the rapid development of new energy, aerospace and other fields, pulse current-assisted forming technology will become one of the key technologies for the development of high-performance materials and the forming of complex components.

[0003] Electrically-assisted tensile testing can deeply explore the influence law of pulse current on solid-state phase transformation, systematically reveal the mechanism of tissue evolution under the assistance of current, and lay a theoretical foundation for the electrically-assisted forming process; while electrically-assisted compression can regulate the deformation behavior of materials through current, study the microstructural changes under the coupling action of stress-electricity-heat, and help optimize the compression forming process parameters of complex components. Both tests involve the influence of multiple factors such as temperature field, electromagnetic field, and mechanical changes, expanding the application boundaries of electrically-assisted forming technology from different dimensions and providing important support for solving the pain points of traditional hot forming processes and promoting the upgrading of material processing and manufacturing technologies.

[0004] At present, traditional tensile testing equipment applies tensile force to specimens through mechanical loading. Traditional test fixtures have limitations in testing pulse current-assisted tensile testing and pulse current-assisted compressive testing, such as the on-off of pulse current, the insulation between the tensile machine and the energized specimen, and the alignment of the test piece relative to the testing machine, which restrict the testing accuracy and safety. With the increasing demand for high-performance materials in new energy, aerospace and other fields, there is an urgent need to develop a test device integrating current assistance, self-alignment and anti-buckling functions. Summary of the Invention

[0005] The purpose of the present invention is to provide a pulse current-assisted tensile and compressive self-aligning test device, aiming to solve the technical problems that traditional tensile testing equipment applies tensile force to specimens through mechanical loading and traditional test fixtures have limitations in testing pulse current-assisted tensile and compressive tests.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is: to provide a pulse current-assisted tensile and compressive self-aligning test device, including: A testing machine, having an upper chuck and a lower chuck; A clamping fixture, connected to the upper chuck and the lower chuck, and the clamping fixture is suitable for clamping and fixing both ends of the specimen; A compression mechanism, connected to the clamping fixture, the compression mechanism having a telescopic end with a degree of freedom of expansion and contraction in the thickness direction of the specimen; A clamping mechanism, connected to the telescopic end of the compression mechanism, the clamping mechanism having a degree of freedom of movement in the thickness direction of the specimen by means of the compression mechanism; Electrode plates, including an upper electrode plate and a lower electrode plate, the clamping mechanism being used to clamp and fix the upper electrode plate and the lower electrode plate, and making the upper electrode plate and the lower electrode plate respectively abut against both side walls of the specimen by means of the compression mechanism, so that the electrode plates provide a pulsed current to the specimen; An anti-buckling mechanism, arranged between the upper chuck and the lower chuck, the anti-buckling mechanism being adapted to slidably clamp the specimen and prevent the specimen from buckling during the compression test; An alignment and clamping mechanism, connected to the upper chuck or the lower chuck, the alignment and clamping mechanism being adapted to clamp the anti-buckling mechanism during the compression test and clamp the specimen during the tensile test, so that the specimen is arranged in alignment in its length direction.

[0007] In a possible implementation, the clamping fixture includes: An upper clamping fixture, connected to the upper chuck and adapted to clamp and fix one end of the specimen, the clamping force of the upper clamping fixture on the specimen being adjustable; A lower clamping fixture, connected to the lower chuck and adapted to clamp and fix the other end of the specimen, the clamping force of the lower clamping fixture on the specimen being adjustable.

[0008] In a possible implementation, the upper clamping fixture includes an upper left fixed clamp body and an upper right fixed clamp body that are fixedly connected to the upper chuck and are spaced apart, an upper left movable clamp body is connected to one side of the upper left fixed clamp body close to the upper right fixed clamp body, an upper right movable clamp body is connected to one side of the upper right fixed clamp body close to the upper left fixed clamp body, and a clamping space for the specimen is formed between the upper left movable clamp body and the upper right movable clamp body; The lower clamping fixture includes a lower left fixed clamp body and a lower right fixed clamp body that are fixedly connected to the lower chuck and are spaced apart, a lower left movable clamp body is connected to one side of the lower left fixed clamp body close to the lower right fixed clamp body, a lower right movable clamp body is connected to one side of the lower right fixed clamp body close to the lower left fixed clamp body, and a clamping space for the specimen is formed between the upper left movable clamp body and the upper right movable clamp body.

[0009] In a possible implementation, the compression mechanism includes: An upper outer compression mechanism, connected to the clamping fixture and close to the upper chuck; An upper inner compression mechanism, connected to the clamping fixture and close to the upper chuck, and arranged side by side with the upper outer compression mechanism in the horizontal direction; The lower outer compression mechanism is connected to the clamping fixture and is close to the lower chuck. The lower inner compression mechanism is connected to the clamping fixture and is close to the lower chuck, and is arranged in parallel with the lower outer compression mechanism in the horizontal direction; the upper outer compression mechanism, the upper inner compression mechanism, the lower outer compression mechanism and the lower inner compression mechanism all have a telescopic end with a telescopic degree of freedom in the thickness direction of the specimen, and the telescopic end is arranged close to the specimen. Wherein, the upper outer compression mechanism and the upper inner compression mechanism are used for telescoping towards one end of the specimen, and the lower outer compression mechanism and the lower inner compression mechanism are used for telescoping towards the other end of the specimen.

[0010] In a possible implementation manner, the upper outer compression mechanism, the upper inner compression mechanism, the lower outer compression mechanism and the lower inner compression mechanism all include: A compression base, which has a cavity inside. A telescopic shaft, which is located in the cavity and is slidably inserted into one side of the compression base, and the telescopic shaft has a degree of freedom of moving along its axial direction. A compression spring, which is sleeved outside the telescopic shaft, and the compression spring is used to pull the telescopic shaft to move along its axial direction towards the inner side of the compression base. A bolt, which is connected to the compression base, and the bolt is used to limit one end of the compression spring.

[0011] In a possible implementation manner, the clamping mechanism includes: A lead screw slide rail base, one end of which is connected to the end of the telescopic shaft extending out of the compression base, and the lead screw slide rail base has a degree of freedom of moving along the axial direction of the telescopic shaft by means of the telescopic shaft. A lead screw chuck, which is connected to the lead screw slide rail base, and the lead screw chuck is suitable for clamping and fixing the upper electrode plate or the lower electrode plate, and the lead screw chuck moves by means of the telescopic shaft to make the upper electrode plate or the lower electrode plate abut against the side wall of the specimen.

[0012] In a possible implementation manner, the anti-buckling mechanism includes: Anti-buckling plates, which are two groups and are respectively arranged on both sides of the specimen. Wear-resistant smooth insulating plates, which are two groups and are respectively arranged on both sides of the specimen. The two groups of wear-resistant smooth insulating plates are located inside the two groups of anti-buckling plates, and the wear-resistant smooth insulating plates are used for slidingly abutting against the specimen. An alignment assembly, which is connected to one side of the specimen and is located between the wear-resistant smooth insulating plate and the anti-buckling plate, and the alignment assembly is suitable for clamping the wear-resistant smooth insulating plate and the specimen. Connecting bolts, which are multiple and are used for locking and fixing the two groups of anti-buckling plates, and the two groups of wear-resistant smooth insulating plates and the alignment assembly are clamped and fixed. There are multiple support springs, which are respectively sleeved outside the multiple connecting bolts. The support springs are used to elastically push against the anti-buckling plates and lock the two groups of anti-buckling plates.

[0013] In a possible implementation, the centering assembly includes: The first comb-shaped clamping and guiding plate; The second comb-shaped clamping and guiding plate, which forms a sliding insertion connection with the first comb-shaped clamping and guiding plate. A space suitable for clamping the wear-resistant smooth insulating plate is formed between the second comb-shaped clamping and guiding plate and the first comb-shaped clamping and guiding plate; The centering spring, with both ends respectively connected to the first comb-shaped clamping and guiding plate and the second comb-shaped clamping and guiding plate. The centering spring is used to pull the first comb-shaped clamping and guiding plate and the second comb-shaped clamping and guiding plate to move towards each other by spring force, thereby adjusting the width of the space.

[0014] In a possible implementation, the centering and clamping mechanism includes: The base, which is connected to the upper chuck or the lower chuck; The first guide rod, with one end hinged to the base. The first guide rod has a rotational freedom around its hinged end; The second guide rod, with one end rotatably connected to the other end of the first guide rod. The second guide rod has a rotational freedom along the direction of its rotating end; The two-way screw clamping and centering assembly, which is connected to the other end of the second guide rod. The two-way screw clamping and centering assembly is suitable for clamping the anti-buckling mechanism during the compression test and clamping the specimen during the tensile test, so that the specimen is centered in its length direction.

[0015] In a possible implementation, the two-way screw clamping and centering assembly includes: The right clamp, with one side connected to the end of the second guide rod; The left clamp, with one end hinged to the right clamp. A clamping space suitable for clamping and fixing the anti-buckling mechanism is formed between the left clamp and the right clamp; The two-way screw, which passes through and is simultaneously screwed to the left clamp and the right clamp. The two-way screw is used to adjust the width of the clamping space between the left clamp and the right clamp.

[0016] The beneficial effects of a pulse current-assisted tensile and compressive self-aligning test device provided by the present invention are as follows: Compared with the prior art, the pulse current-assisted tensile and compressive self-aligning test device of the present invention includes a testing machine, a clamping fixture, a compression mechanism, a clamping mechanism, electrode plates, an anti-buckling mechanism, and a centering and clamping mechanism. By clamping the specimen with the clamping fixture and using the compression mechanism to push against the clamping mechanism, the clamping mechanism can clamp and fix the electrode plates. The anti-buckling mechanism can prevent the specimen from buckling and deforming, and the centering and clamping mechanism can keep the specimen centered in the length direction. The pulse current-assisted tensile and compressive self-aligning test device provided by the present invention can achieve self-alignment of the specimen, ensure the safety and accuracy of the tensile and compressive test processes, thereby promoting the wide application of pulse current-assisted tensile and compressive test technologies in the testing of material mechanical properties, solving the technical problems of the limitations of traditional test fixtures in pulse current-assisted tensile and compressive tests, and having the functions of integrating current assistance, self-alignment, and anti-buckling. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0018] Figure 1 FIG. is a schematic structural diagram of a pulse current-assisted tensile and compressive self-aligning test device provided by an embodiment of the present invention; Figure 2 FIG. is a schematic structural diagram of an upper chuck of a pulse current-assisted tensile and compressive self-aligning test device provided by an embodiment of the present invention; Figure 3 FIG. is a schematic structural diagram of a lower chuck of a pulse current-assisted tensile and compressive self-aligning test device provided by an embodiment of the present invention; Figure 4 FIG. is a schematic structural diagram of an upper clamping fixture of a pulse current-assisted tensile and compressive self-aligning test device provided by an embodiment of the present invention; Figure 5 FIG. is a schematic structural diagram of a lower clamping fixture of a pulse current-assisted tensile and compressive self-aligning test device provided by an embodiment of the present invention; Figure 6 FIG. is a schematic structural diagram of a compression mechanism and a clamping mechanism of a pulse current-assisted tensile and compressive self-aligning test device provided by an embodiment of the present invention; Figure 7 FIG. is an exploded structural diagram of an anti-buckling mechanism of a pulse current-assisted tensile and compressive self-aligning test device provided by an embodiment of the present invention; Figure 8 For Figure 7 Schematic diagram of the centering component and the buckling restraint plate connection structure in Figure 9 For Figure 7 Usage state diagram of the buckling restraint mechanism in Figure 10 Schematic diagram of the structure of the centering component of a pulse current assisted tensile compression self-centering test device provided by an embodiment of the present invention; Figure 11 Schematic diagram of the structure of the centering component of a pulse current assisted tensile compression self-centering test device provided by an embodiment of the present invention; Figure 12 Schematic diagram of the structure of the centering clamping mechanism of a pulse current assisted tensile compression self-centering test device provided by an embodiment of the present invention; Figure 13 Schematic diagram of the structure of the two-way screw clamping centering component of a pulse current assisted tensile compression self-centering test device provided by an embodiment of the present invention.

[0019] Explanation of reference numerals: 1. Upper chuck; 2. Lower chuck; 3. Compression mechanism; 31. Upper outer compression mechanism; 311. Compression base; 312. Telescopic shaft; 313. Compression spring; 314. Bolt; 32. Upper inner compression mechanism; 33. Lower outer compression mechanism; 4. Clamping mechanism; 41. Lead screw slide rail base; 42. Lead screw chuck; 5. Electrode plate; 51. Upper electrode plate; 52. Lower electrode plate; 53. Bolt hole; 6. Buckling restraint mechanism; 61. Buckling restraint plate; 62. Wear-resistant smooth insulating plate; 63. Centering component; 631. First tooth comb-shaped clamping and guiding plate; 632. Second tooth comb-shaped clamping and guiding plate; 633. Centering spring; 64. Connecting bolt; 65. Support spring; 66. Perspective window; 7. Centering clamping mechanism; 71. Base; 72. First guide rod; 73. Second guide rod; 74. Two-way bolt clamping centering component; 741. Left clamp; 742. Right clamp; 743. Two-way screw; 8. Upper clamping fixture; 81. Upper left fixed clamp body; 82. Upper right fixed clamp body; 83. Upper left movable clamp body; 84. Upper right movable clamp body; 9. Lower clamping fixture; 91. Lower left fixed clamp body; 92. Lower right fixed clamp body; 93. Lower left movable clamp body; 94. Lower right movable clamp body; 10. Specimen. Detailed implementation manners

[0020] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clear and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0021] In a material mechanics test, when the specimen is kept centered during the tensile and compression tests, it means that the axis of the specimen coincides with the loading axis of the testing machine in the fixture or other fixing device of the testing machine. Simply put, it means that the specimen should be placed correctly and straight, without being skewed. The centering degree of the load chain can be simply understood as whether the center lines of the force sensor, fixture, adapter and specimen are on the same straight line. In a tensile test, if the centering degree of the load chain is not good, it will cause the test sample to be subjected to an additional skew force during the loading process, resulting in uneven stress and affecting the authenticity of the test results. Therefore, when testing the specimen 10, keeping the specimen 10 centered helps to improve the accuracy of the test results.

[0022] Please refer to Figures 1 to 13 together. Now, a pulse current-assisted tensile and compression self-centering test device provided by the present invention will be described. The pulse current-assisted tensile and compression self-centering test device includes a testing machine, a clamping fixture, a compression mechanism 3, a clamping mechanism 4, electrode plates 5, an anti-buckling mechanism 6 and a centering clamping mechanism 7. The testing machine has an upper chuck 1 and a lower chuck 2; the clamping fixture is connected to the upper chuck 1 and the lower chuck 2, and the clamping fixture is suitable for clamping and fixing both ends of the specimen 10; the compression mechanism 3 is connected to the clamping fixture, and the compression mechanism 3 has a telescopic end with a telescopic degree of freedom in the thickness direction of the specimen 10; the clamping mechanism 4 is connected to the telescopic end of the compression mechanism 3, and the clamping mechanism 4 has a moving degree of freedom in the thickness direction of the specimen 10 by means of the compression mechanism 3; the electrode plates 5 include an upper electrode plate 51 and a lower electrode plate 52, and the clamping mechanism 4 is used to clamp and fix the upper electrode plate 51 and the lower electrode plate 52, and make the upper electrode plate 51 and the lower electrode plate 52 respectively abut against the side walls of both ends of the specimen 10 by means of the compression mechanism 3, so that the electrode plates 5 provide a pulse current to the specimen 10; the anti-buckling mechanism 6 is arranged between the upper chuck 1 and the lower chuck 2, and the anti-buckling mechanism 6 is suitable for slidingly clamping the specimen 10 and preventing the specimen 10 from buckling during the compression test; the centering clamping mechanism 7 is connected to the upper chuck 1 or the lower chuck 2, and the centering clamping mechanism 7 is suitable for clamping the anti-buckling mechanism 6 during the compression test and clamping the specimen 10 during the tensile test, so that the specimen 10 is centered in its length direction.

[0023] A pulse current-assisted tensile and compressive self-centering test device provided by the present invention, compared with the prior art, clamps the specimen 10 by the clamping fixture, connects the clamping fixture to the testing machine and clamps and fixes the specimen 10. By pulling the clamping mechanism 4 to move through the compression mechanism 3, the clamping mechanism 4 can clamp and fix the electrode sheet 5, so that the electrode sheet 5 can provide a pulse current to the specimen 10; when the specimen is subjected to a compression test, the anti-buckling mechanism 6 slides and abuts against the specimen 10 and can prevent the specimen 10 from buckling. By clamping the anti-buckling mechanism 6 and the specimen 10 respectively during the compression and tensile tests through the centering and clamping mechanism 7, the specimen 10 can be kept centered in the length direction, ensuring the safety and accuracy of the tensile and compression test processes, thereby promoting the wide application of the pulse current-assisted tensile and compression test technology in the testing of the mechanical properties of materials, and solving the technical problem of the limitations of traditional test fixtures in the pulse current-assisted tensile and compression tests.

[0024] In this embodiment, the testing machine is a universal testing machine, which can perform tensile and compression tests on the specimen 10. The clamping fixture is installed on the upper chuck 1 and the lower chuck 2 to realize the clamping and fixing of the upper and lower ends of the specimen 10. Through the cooperation of the compression mechanism 3 and the clamping mechanism 4, the electrode sheet 5 can always be in contact with the specimen 10, ensuring that a pulse current can be provided during the test, realizing pulse current-assisted tensile and compression; at the same time, by using the anti-buckling mechanism 6 and the centering and clamping mechanism 7, the self-centering of the specimen 10 during the compression test can be realized, effectively improving the experimental accuracy and preventing the occurrence of non-centering phenomena. Bolt holes 53 are provided on both the upper electrode sheet 51 and the lower electrode sheet 52, and the cable is connected to the electrode sheet 5 through the bolt holes 53 to form a pulse current loop. By changing the parameters of the pulse power supply, such as the current magnitude, pulse frequency, and duty cycle, the influence of different current characteristics on the electroplastic effect of the material can be evaluated.

[0025] In some embodiments, refer to Figures 1 to 5 , the clamping fixture includes an upper clamping fixture 8 and a lower clamping fixture 9. The upper clamping fixture 8 is connected to the upper chuck 1 and is suitable for clamping and fixing one end of the specimen 10, and the clamping force of the upper clamping fixture 8 on the specimen 10 can be adjusted; the lower clamping fixture 9 is connected to the lower chuck 2 and is suitable for clamping and fixing the other end of the specimen 10, and the clamping force of the lower clamping fixture 9 on the specimen 10 can be adjusted. The upper clamping fixture 8 and the lower clamping fixture 9 are arranged in alignment in the vertical direction. Grooves are provided at the bottom of the upper chuck 1 and the top of the lower chuck 2, and the upper clamping fixture 8 and the lower clamping fixture 9 are respectively arranged inside the two grooves, which are power-connected to the upper chuck 1 or the lower chuck 2. By providing power inside the upper chuck 1 and the lower chuck 2, the upper clamping fixture 8 and the lower clamping fixture 9 can clamp and fix the specimen 10. By providing different degrees of power, the clamping force on the specimen 10 can be adjusted.

[0026] In some embodiments, refer to Figures 1 to 5, the upper clamping fixture 8 includes an upper left fixed clamp body 81 and an upper right fixed clamp body 82 that are fixedly connected to the upper chuck 1 and are spaced apart. An upper left movable clamp body 83 is connected to the side of the upper left fixed clamp body 81 close to the upper right fixed clamp body 82, and an upper right movable clamp body 84 is connected to the side of the upper right fixed clamp body 82 close to the upper left fixed clamp body 81. A clamping space for the specimen 10 is formed between the upper left movable clamp body 83 and the upper right movable clamp body 84; the lower clamping fixture 9 includes a lower left fixed clamp body 91 and a lower right fixed clamp body 92 that are fixedly connected to the lower chuck 2 and are spaced apart. A lower left movable clamp body 93 is connected to the side of the lower left fixed clamp body 91 close to the lower right fixed clamp body 92, and a lower right movable clamp body 94 is connected to the side of the lower right fixed clamp body 92 close to the lower left fixed clamp body 91. A clamping space for the specimen 10 is formed between the upper left movable clamp body 83 and the upper right movable clamp body 84. The upper left fixed clamp body 81 and the upper right fixed clamp body 82 are symmetrically arranged, and the lower left fixed clamp body 91 and the lower right fixed clamp body 92 are symmetrically arranged. The upper left movable clamp body 83 and the upper right movable clamp body 84 are approximately symmetrically arranged, and their structures are slightly different. The lower left movable clamp body 93 and the lower right movable clamp body 94 are approximately symmetrically arranged, and their structures are slightly different. The above-mentioned fixed clamp body is in a fixed state, and the movable clamp body is in a movable state, and it is power-connected to the upper chuck 1 or the lower chuck 2. By providing different degrees of power, the clamping degree or strength between the above-mentioned movable clamp bodies can be controlled, so that the specimen 10 can be clamped and fixed.

[0027] In some embodiments, please refer to Figures 1 to 6 , the compression mechanism 3 includes an upper outer compression mechanism 31, an upper inner compression mechanism 32, a lower outer compression mechanism 33 and a lower inner compression mechanism (not shown in the figure). The upper outer compression mechanism 31 is connected to the clamping fixture and is close to the upper chuck 1; the upper inner compression mechanism 32 is connected to the clamping fixture and is close to the upper chuck 1, and is arranged side by side with the upper outer compression mechanism 31 in the horizontal direction; the lower outer compression mechanism 33 is connected to the clamping fixture and is close to the lower chuck 2; the lower inner compression mechanism is connected to the clamping fixture and is close to the lower chuck 2, and is arranged side by side with the lower outer compression mechanism 33 in the horizontal direction; the upper outer compression mechanism 31, the upper inner compression mechanism 32, the lower outer compression mechanism 33 and the lower inner compression mechanism all have a telescopic end with a telescopic freedom degree in the thickness direction of the specimen 10, and the telescopic end is arranged close to the specimen 10; wherein, the upper outer compression mechanism 31 and the upper inner compression mechanism 32 are used for telescoping towards one end of the specimen 10, and the lower outer compression mechanism 33 and the lower inner compression mechanism are used for telescoping towards the other end of the specimen 10. The upper outer compression mechanism 31 and the upper inner compression mechanism 32 are a group and are spaced apart, and are arranged at the upper chuck 1 and are located on one side of the specimen 10; the lower outer compression mechanism 33 and the lower inner compression mechanism are a group and are spaced apart, and are arranged at the lower chuck 2 and are located on one side of the specimen 10, and are on the same side of the specimen 10 as the upper outer compression mechanism 31.

[0028] Specifically, a space for accommodating the upper outer compression mechanism 31 and the upper inner compression mechanism 32 is provided on the upper left movable clamping body 83, and a space for accommodating the lower outer compression mechanism 33 and the lower inner compression mechanism is provided on the lower left movable clamping body 93, without affecting the clamping and fixing of the specimen 10.

[0029] In some embodiments, refer to Figures 1 to 6 , the upper outer compression mechanism 31, the upper inner compression mechanism 32, the lower outer compression mechanism 33 and the lower inner compression mechanism all include a compression base 311, a telescopic shaft 312, a compression spring 313 and a bolt 314. The inner side of the compression base 311 has a cavity; the telescopic shaft 312 is located in the cavity and is slidably inserted into one side of the compression base 311. The telescopic shaft 312 has a degree of freedom of movement along its axial direction; the compression spring 313 is sleeved outside the telescopic shaft 312. The compression spring 313 is used to pull the telescopic shaft 312 to move along its axial direction towards the inner side of the compression base 311; the bolt 314 is connected to the compression base 311, and the bolt 314 is used to limit one end of the compression spring 313. With the elastic force of the compression spring 313, the telescopic shaft 312 can provide a driving force that always makes the electrode plate 5 abut against the wall surface of the specimen 10. In this way, the current on the electrode plate 5 can be conducted to the specimen 10, wherein the clamping mechanism 4 is made of an insulating material to avoid current conduction. One end of the telescopic shaft 312 extends out of the compression base 311, and the other end is located inside the compression base 311. The compression spring 313 can provide a retracting force, so that the outer end of the telescopic shaft 312 (the end located outside the compression base 311) has a force that always contracts towards the inside of the compression base 311, so that the electrode plate 5 can abut against the wall surface of the specimen 10. Specifically, the bolt 314 is arranged at one end of the compression base 311 away from the clamping mechanism 4, and one end of the compression spring 313 abuts against the bolt 314, and the other end is connected to the telescopic shaft 312 and is used to pull the telescopic shaft 312 to move. The telescopic end of the compression mechanism 3 is the outer end of the telescopic column.

[0030] In some embodiments, refer to Figures 1 to 6, the clamping mechanism 4 includes a lead screw slide rail base 41 and a lead screw chuck 42. One end of the lead screw slide rail base 41 is connected to the end of the telescopic shaft 312 extending out of the compression base 311. The lead screw slide rail base 41 has a degree of freedom of axial movement along the telescopic shaft 312 by means of the telescopic shaft 312; the lead screw chuck 42 is connected to the lead screw slide rail base 41, and the lead screw chuck 42 is adapted to clamp and fix the upper electrode plate 51 or the lower electrode plate 52. The lead screw chuck 42 moves by means of the telescopic shaft 312 so that the upper electrode plate 51 or the lower electrode plate 52 abuts against the side wall of the specimen 10. The lead screw slide rail base 41 is a prior art, including a seat body provided with a slide rail and a lead screw threadedly connected to the seat body. The lead screw chuck 42 includes a lead screw nut, a fixed chuck and a movable chuck. The fixed chuck is fixedly connected to one side of the upper end of the seat body. The lead screw nut is threadedly connected to the lead screw, and the lead screw nut is also slidably connected to the slide rail. By rotating the lead screw, the lead screw nut slides on the slide rail. The movable chuck is connected to the lead screw nut, so the movable chuck moves simultaneously with the lead screw nut, and thus the distance between the movable chuck and the fixed chuck can be adjusted, and further the clamping and fixing of the electrode plates 5 with different thicknesses can be adjusted. By means of the compression spring 313, the lead screw slide rail base 41 can be pulled, so that the electrode plate 5 always moves towards the direction close to the specimen 10, and further closely adheres to the specimen 10.

[0031] In some embodiments, please refer to Figure 1 、 Figures 7 to 11 , the anti-buckling mechanism 6 includes anti-buckling plates 61, wear-resistant smooth insulating plates 62, centering components 63, connecting bolts 64 and supporting springs 65. There are two groups of anti-buckling plates 61 and they are respectively arranged on both sides of the specimen 10; there are two groups of wear-resistant smooth insulating plates 62 and they are respectively arranged on both sides of the specimen 10. The two groups of wear-resistant smooth insulating plates 62 are located inside the two groups of anti-buckling plates 61, and the wear-resistant smooth insulating plates 62 are used to slidably abut against the specimen 10; the centering component 63 is connected to one side of the specimen 10 and is located between the wear-resistant smooth insulating plate 62 and the anti-buckling plate 61. The centering component 63 is adapted to clamp the wear-resistant smooth insulating plate 62 and the specimen 10; there are multiple connecting bolts 64 and they are used to lock and fix the two groups of anti-buckling plates 61, and the two groups of wear-resistant smooth insulating plates 62 and the centering component 63 are clamped and fixed; there are multiple supporting springs 65 and they are respectively sleeved on the outer sides of the multiple connecting bolts 64. The supporting springs 65 are used to elastically push against the anti-buckling plates 61 and lock the two groups of anti-buckling plates 61. The two groups of wear-resistant smooth insulating plates 62 clamp the specimen 10. After clamping, the specimen 10 can slide between the two groups of wear-resistant smooth insulating plates 62. The two groups of anti-buckling plates 61 are connected and fixed by the connecting bolts 64, realizing the fixation of the two groups of wear-resistant smooth insulating plates 62 and the fixation of the centering component 63, so that the specimen 10 is prevented from buckling and deforming during the compression test and the centering setting of the specimen 10 is maintained.

[0032] Specifically, grooves are provided on the inner sides of the two sets of anti-buckling plates 61. The wear-resistant smooth insulating plate 62 and the centering assembly 63 can be snapped into the grooves. A perspective window 66 is provided in alignment with the middle parts of the anti-buckling plate 61 and the wear-resistant smooth insulating plate 62. The specimen 10 can be seen through the perspective window 66, so as to facilitate observing the changes occurring to the specimen 10 (measurement can be combined with the use of DIC equipment).

[0033] In some embodiments, refer to Figures 8 to 11 , the centering assembly 63 includes a first comb-shaped clamping and guiding plate 631, a second comb-shaped clamping and guiding plate 632, and a centering spring 633. One side of the first comb-shaped clamping and guiding plate 631 is arranged in a comb-shaped structure, and one side of the second comb-shaped clamping and guiding plate 632 is also arranged in a comb-shaped structure. The two sets of comb-shaped structures are inserted and matched with each other. The second comb-shaped clamping and guiding plate 632 forms a sliding insertion connection with the first comb-shaped clamping and guiding plate 631, and a space suitable for clamping the wear-resistant smooth insulating plate 62 is formed between the second comb-shaped clamping and guiding plate 632 and the first comb-shaped clamping and guiding plate 631; both ends of the centering spring 633 are respectively connected to the first comb-shaped clamping and guiding plate 631 and the second comb-shaped clamping and guiding plate 632. The centering spring 633 is used to spring-pull the first comb-shaped clamping and guiding plate 631 and the second comb-shaped clamping and guiding plate 632 to move towards each other, thereby adjusting the space width. The clamping and fixing of the wear-resistant smooth insulating plate 62 can be realized through the elastic pulling force of the centering spring 633.

[0034] In some embodiments, refer to Figures 12 to 13 , the centering and clamping mechanism 7 includes a base 71, a first guide rod 72, a second guide rod 73, and a bidirectional screw clamping and centering assembly 74. The base 71 is connected to the upper chuck 1 or the lower chuck 2; one end of the first guide rod 72 is hinged to the base 71, and the first guide rod 72 has a rotational degree of freedom around its hinged end; one end of the second guide rod 73 is rotatably connected to the other end of the first guide rod 72, and the second guide rod 73 has a rotational degree of freedom along the rotational end; the bidirectional screw clamping and centering assembly 74 is connected to the other end of the second guide rod 73. The bidirectional screw clamping and centering assembly 74 is suitable for clamping the anti-buckling mechanism 6 during the compression test and clamping the specimen during the tensile test, so that the specimen 10 is centered in its length direction. By screwing the bidirectional screw clamping and centering assembly 74, the clamping of the specimen 10 and the anti-buckling mechanism 6 can be realized, which are respectively used for the tensile test and the compression test of the specimen 10. Since the specimen 10 can be centered only by the bidirectional screw clamping and centering assembly 74 during the tensile test, and the specimen 10 will deform itself during the compression test, it is necessary to use the anti-buckling mechanism 6 and make the bidirectional screw clamping and centering assembly 74 clamp the anti-buckling mechanism 6, so that the centering setting of the specimen 10 can be maintained.

[0035] In some embodiments, refer to Figures 12 to 13, the bi-directional screw clamping and centering assembly 74 includes a left clamp 741, a right clamp 742 and a bi-directional screw 743. One side of the right clamp 742 ( Figure 12 the bottom in this case) is connected to the end of the second guide rod 73 ( Figure 12 the upper end in this case); one end of the right clamp 742 close to the left clamp 741 is hinged to the left clamp 741, and a clamping space suitable for clamping and fixing the anti-buckling mechanism 6 is formed between the left clamp 741 and the right clamp 742; the bi-directional screw 743 passes through and is simultaneously screwed to the left clamp 741 and the right clamp 742, and the bi-directional screw 743 is used to adjust the width of the clamping space between the left clamp 741 and the right clamp 742. Both the left clamp 741 and the right clamp 742 have mutually aligned screw holes, the bi-directional screw 743 passes through the two screw holes and extends out from the outside of the left clamp 741. The left clamp 741 and the right clamp 742 are approximately symmetric structures, similar to the structure of a clip. One end of the two forms a hinge, and the other end forms a clamping space for contacting and clamping the anti-buckling mechanism 6 or the specimen 10 ( Figures 12 - 13 in this case, the opening or clamping action is carried out horizontally).

[0036] Specifically, there are two parts of external threads with different helix directions on the bi-directional screw 743, which are respectively threadedly connected to the left clamp 741 and the right clamp 742. By screwing one end of the bi-directional screw 743, the left clamp 741 and the right clamp 742 can be simultaneously rotated, thereby expanding or reducing the clamping space, which is beneficial to clamping and fixing the anti-buckling mechanism 6 and keeping the specimen 10 in a centered state.

[0037] The process and embodiments of the tensile test of the present invention: Install and fix the upper clamping fixture 8 to the upper chuck 1 of the universal testing machine, and install and fix the lower clamping fixture 9 to the lower chuck 2 of the universal testing machine; Install the upper electrode plate 51 to the upper clamping mechanism 4 and fix it by using the inner and outer two clamping mechanisms 4; Install the lower electrode plate 2 to the lower clamping mechanism 4 and also fix it by using the inner and outer two clamping mechanisms 4; Place the specimen 10 in the upper chuck 1 and the lower chuck 2 of the testing machine; Clamp the specimen 10 through the centering and clamping mechanism 7 (when the specimen 10 undergoes a tensile test, the anti-buckling mechanism 6 is not used, and only the centering and clamping mechanism 7 is used) to achieve its self-centering; Pull the upper electrode plate 51 outwards, and clamp the upper end of the specimen 10 through the compression force of the upper two compression mechanisms 3. Pull the lower electrode plate 52 outwards, and clamp the lower end of the specimen 10 through the compression force of the lower two compression mechanisms 3; Do not install the anti-buckling mechanism 6; Achieve the on-off of the current during the tensile process and the self-centering of the test piece through the above steps; Clamp the upper chuck 1 and the lower chuck 2 of the testing machine to install the specimen 10; Start the tensile test and measure on the front of the specimen through the DIC device to obtain the tensile test data assisted by the pulsed current.

[0038] Process and embodiments of the compression test of the present invention: Install and fix the upper clamping fixture 8 to the upper chuck 1 of the universal testing machine, and install and fix the lower clamping fixture 9 to the lower chuck 2 of the universal testing machine; Install the upper electrode plate 51 at the upper clamping mechanism 4 and fix it through the inner and outer clamping mechanisms 4; Install the lower electrode plate 52 at the lower clamping mechanism 4 and also fix it through the inner and outer clamping mechanisms 4; Place the specimen 10 inside the upper chuck 1 and the lower chuck 2 of the testing machine; Match and install the anti-buckling mechanism 6 with the specimen 10, pull apart the centering component 63 of the anti-buckling mechanism 6, place the specimen 10 in, and achieve the centering position relationship between the specimen 10 and the anti-buckling mechanism 6. Clamp the specimen 10 through the connecting bolt 64 and the support spring 65, and adjust the support force of the support spring 65 and the tightening force of the connecting bolt 64 according to the mechanical properties of the specimen 10. Complete the installation of the specimen 10 and the anti-buckling mechanism 6 through the above steps, and achieve the pre-clamping of the specimen 10 and the centering relative to the anti-buckling mechanism 6; Clamp the anti-buckling mechanism 6 with the specimen 10 installed through the centering clamping mechanism 7 to achieve the self-centering of the specimen 10 with the anti-buckling mechanism 6 installed; Pull the upper electrode plate 51 outwards, clamp the upper end of the specimen 10 through the compression force of the upper two compression mechanisms 3, pull the lower electrode plate 52 outwards, and clamp the lower end of the specimen 10 through the compression force of the lower two compression mechanisms 3; Achieve the on-off of the current during the compression process, the self-centering of the test piece, and the anti-buckling during the compression process through the above steps; Clamp the upper chuck 1 and the lower chuck 2 of the testing machine to complete the installation of the specimen 10; Start the compression. Through the DIC device, measurements can be carried out on the front and side of the specimen 10 to verify the data integrity and obtain the compression test data under the assistance of pulsed current.

[0039] The present invention can meet the process requirements of various types and specifications of specimens 10, can simultaneously implement the pulsed current-assisted tensile test and the pulsed current-assisted compression test, can ensure the self-centering of the specimen 10 relative to the testing machine, has high experimental result accuracy, can ensure the consistency of the energized environment, is convenient to operate, and has strong test versatility.

[0040] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A pulse current-assisted tensile compression self-aligning test device, characterized in that Comprising: A testing machine, having an upper chuck and a lower chuck; A clamping fixture, connected to the upper chuck and the lower chuck, the clamping fixture being adapted to clamp and fix both ends of a specimen; A compression mechanism, connected to the clamping fixture, the compression mechanism having a telescopic end with a degree of freedom of expansion and contraction in the thickness direction of the specimen; A clamping mechanism, connected to the telescopic end of the compression mechanism, the clamping mechanism having a degree of freedom of movement in the thickness direction of the specimen by means of the compression mechanism; Electrode plates, including an upper electrode plate and a lower electrode plate, the clamping mechanism being used to clamp and fix the upper electrode plate and the lower electrode plate, and causing the upper electrode plate and the lower electrode plate to respectively abut against the side walls at both ends of the specimen by means of the compression mechanism, so that the electrode plates provide a pulsed current to the specimen; An anti-buckling mechanism, provided between the upper chuck and the lower chuck, the anti-buckling mechanism being adapted to slidably clamp the specimen and prevent the specimen from buckling during a compression test; An alignment clamping mechanism, connected to the upper chuck or the lower chuck, the alignment clamping mechanism being adapted to clamp the anti-buckling mechanism during a compression test and clamp the specimen during a tensile test, so that the specimen is aligned in its length direction.

2. The pulse current-assisted tensile and compressive self-centering test device according to claim 1, characterized in that, The clamping fixture includes: An upper clamping fixture, connected to the upper chuck and adapted to clamp and fix one end of the specimen, the clamping force of the upper clamping fixture on the specimen being adjustable; A lower clamping fixture, connected to the lower chuck and adapted to clamp and fix the other end of the specimen, the clamping force of the lower clamping fixture on the specimen being adjustable.

3. The pulse current assisted tensile-compressive self-centering test device according to claim 2, characterized in that, The upper clamping fixture includes an upper left fixed clamp body and an upper right fixed clamp body that are fixedly connected to the upper chuck and are spaced apart, an upper left movable clamp body is connected to the side of the upper left fixed clamp body close to the upper right fixed clamp body, and an upper right movable clamp body is connected to the side of the upper right fixed clamp body close to the upper left fixed clamp body. A clamping space for the specimen is formed between the upper left movable clamp body and the upper right movable clamp body; The lower clamping fixture includes a lower left fixed clamp body and a lower right fixed clamp body that are fixedly connected to the lower chuck and are spaced apart, a lower left movable clamp body is connected to the side of the lower left fixed clamp body close to the lower right fixed clamp body, and a lower right movable clamp body is connected to the side of the lower right fixed clamp body close to the lower left fixed clamp body. A clamping space for the specimen is formed between the upper left movable clamp body and the upper right movable clamp body.

4. A pulse current-assisted tensile-compressive self-aligning test device according to claim 1, characterized in that, The compression mechanism includes: An upper outer compression mechanism, connected to the clamping fixture and close to the upper chuck; An upper inner compression mechanism, connected to the clamping fixture and close to the upper chuck, and arranged side by side with the upper outer compression mechanism in the horizontal direction; A lower outer compression mechanism, connected to the clamping fixture and close to the lower chuck; A lower inner compression mechanism, connected to the clamping fixture and close to the lower chuck, and arranged side by side with the lower outer compression mechanism in the horizontal direction; the upper outer compression mechanism, the upper inner compression mechanism, the lower outer compression mechanism, and the lower inner compression mechanism all have a telescopic end with a degree of freedom of expansion and contraction in the thickness direction of the specimen, and the telescopic end is close to the specimen; Wherein, the upper outer compression mechanism and the upper inner compression mechanism are used to expand and contract towards one end of the specimen, and the lower outer compression mechanism and the lower inner compression mechanism are used to expand and contract towards the other end of the specimen.

5. The pulse current-assisted tensile and compressive self-aligning test device according to claim 4, wherein The upper outer compression mechanism, the upper inner compression mechanism, the lower outer compression mechanism, and the lower inner compression mechanism all include: A compression base with a cavity inside. A telescopic shaft located in the cavity, slidably inserted into one side of the compression base, and the telescopic shaft has a degree of freedom of axial movement along its axis. A compression spring sleeved outside the telescopic shaft, and the compression spring is used to pull the telescopic shaft to move along its axis in the direction close to the inner side of the compression base. A bolt connected to the compression base, and the bolt is used to limit one end of the compression spring.

6. The pulse current-assisted tensile and compressive self-aligning test device according to claim 5, characterized in that, The clamping mechanism includes: A lead screw slide rail base, one end of which is connected to the end of the telescopic shaft extending out of the compression base, and the lead screw slide rail base has a degree of freedom of axial movement along the telescopic shaft by means of the telescopic shaft. A lead screw chuck connected to the lead screw slide rail base, and the lead screw chuck is suitable for clamping and fixing the upper electrode plate or the lower electrode plate. The lead screw chuck moves by means of the telescopic shaft to make the upper electrode plate or the lower electrode plate abut against the side wall of the specimen.

7. The pulse current-assisted tensile compression self-aligning test device according to claim 1, wherein The anti-buckling mechanism includes: Two anti-buckling plates respectively arranged on both sides of the specimen. Two wear-resistant smooth insulating plates respectively arranged on both sides of the specimen. The two wear-resistant smooth insulating plates are located inside the two anti-buckling plates, and the wear-resistant smooth insulating plates are used to slidably abut against the specimen. An alignment assembly connected to one side of the specimen and located between the wear-resistant smooth insulating plate and the anti-buckling plate. The alignment assembly is suitable for clamping the wear-resistant smooth insulating plate and the specimen. A plurality of connecting bolts for locking and fixing the two anti-buckling plates, and the two wear-resistant smooth insulating plates and the alignment assembly are clamped and fixed. A plurality of support springs respectively sleeved outside the plurality of connecting bolts, and the support springs are used to elastically push the anti-buckling plate and lock the two anti-buckling plates.

8. The pulse current assisted tensile compression self-aligning test device according to claim 7, wherein, The alignment assembly includes: A first comb-shaped clamping and guiding plate. A second comb-shaped clamping and guiding plate that forms a sliding insertion with the first comb-shaped clamping and guiding plate. A space suitable for clamping the wear-resistant smooth insulating plate is formed between the second comb-shaped clamping and guiding plate and the first comb-shaped clamping and guiding plate. An alignment spring, the two ends of which are respectively connected to the first comb-shaped clamping and guiding plate and the second comb-shaped clamping and guiding plate. The alignment spring is used to pull the first comb-shaped clamping and guiding plate and the second comb-shaped clamping and guiding plate to move towards each other by spring force, thereby adjusting the width of the space.

9. The pulse current-assisted tensile and compressive self-centering test device according to claim 1, characterized in that The alignment clamping mechanism includes: A base connected to the upper chuck or the lower chuck. A first guide rod, one end of which is hinged to the base, and the first guide rod has a degree of freedom of rotation around its hinged end. A second guide rod, one end of which is rotatably connected to the other end of the first guide rod, and the second guide rod has a degree of freedom of rotation along the rotation end. A two-way screw clamping and alignment assembly connected to the other end of the second guide rod. The two-way screw clamping and alignment assembly is suitable for clamping the anti-buckling mechanism during the compression test and clamping the specimen during the tensile test to align the specimen in its length direction.

10. A pulse current-assisted tensile compression self-aligning test device according to claim 9, characterized in that, The two-way screw clamping and alignment assembly includes: A right clamp, one side of which is connected to the end of the second guide rod. The left clamp, one end of which is hinged to the right clamp, a clamping space for clamping and fixing the anti-buckling mechanism is formed between the left clamp and the right clamp; A bidirectional screw rod passes through and is simultaneously screwed to the left clamp and the right clamp, and the bidirectional screw rod is used to adjust the width of the clamping space between the left clamp and the right clamp.

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