Tensile strength testing device and its use in single or double material components

Abstract

The application discloses a tensile strength testing device and application thereof in single-material or double-material components, and is characterized in that the tensile strength testing device is connected by a clamping assembly, a connecting assembly and a support, so that after the first support and / or the second support are connected with a force applying unit for connecting an external force applying unit, the force applying unit can provide a force to make the first support and the second support relatively move in a mutual approaching direction, the first connecting assembly connected with the first support and the second connecting assembly connected with the second support can respectively drive the first clamping assembly and the second clamping assembly to move in a mutual moving away direction, and the test piece clamped on the first clamping assembly and the second clamping assembly is subjected to a tensile force, so that the tensile force is applied. The device is flexible in operation, good in test piece adaptability, convenient for experimenters to operate, and high in experimental efficiency and applicability.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of tensile testing device and component testing technology, in particular to a tensile strength testing device and its application in single material or double material components. BACKGROUND

[0002] The tensile strength of rock, concrete and rock-concrete composite components is an important mechanical parameter in engineering construction. There are two methods for measuring the tensile strength of single material or double material, namely direct measurement method and indirect measurement method. Among them, the indirect measurement method is the splitting tensile test method, and the direct measurement method is the uniaxial tensile test method. For the uniaxial tensile test method, the center of the test specimen and the experimental fixture need to be on a straight line to ensure that the load is applied to the center of the test specimen, so that the tensile strength of the test specimen can be accurately measured. Since the experimental fixture needs to precisely clamp the experimental component and ensure that the tensile force line passes through the center of the component, the operation is difficult, and many studies have not used the direct tensile method to obtain the tensile strength of single material or double material. For the indirect measurement method, cubic or disc configurations are mainly used. Although these components are easy to process and the test is relatively simple, the indirect splitting tensile method makes the stress state of rock or concrete complex and diverse, and the tensile strength obtained by the test is greatly different from that obtained by the uniaxial tensile test method. In particular, there is a large error in solving the interfacial tensile strength of double material test specimens by splitting tensile test, because the single material splitting tensile solution formula cannot be directly applied to the splitting solution of double material test specimens, and the stress distribution of double material test specimens is asymmetric, while the single material splitting tensile formula is derived based on homogeneous material and symmetric stress distribution conditions.

[0003] Currently, some researchers have made many improvements and innovations to directly obtain the tensile strength of brittle materials. For example, Cao Rihong [1] invented a rock direct tensile device, which can obtain the tensile strength of rock under different pressure measurement conditions. Based on a rock shear rheometer, the inner and outer frames of the device are sleeved. During the experiment, the vertical shear device of the rock shear rheometer applies a load to the top of the inner frame, while the outer frame is fixed, and the rock is directly vertically stretched stably. The tensile strength of the rock can be accurately obtained. Zhang Xutao [2] designed a bonding centering device, which is composed of a stand, a bottom plate, an upper and lower pull head positioning sleeve and other components. The bonding centering device is also provided with a knob that can adjust the thickness of the adhesive and can be finely adjusted. The rock is placed in the bonding centering device, the tensile device is connected to the universal testing machine, and the computer automatically records the tensile force-displacement information. Finally, the tensile stress value of the test specimen can be measured. He Xin, Liu Jianfeng, etc. [3]Others have also disclosed a rock tensile testing apparatus of their design incorporated into a triaxial lateral compressive stress rock tensile test. This apparatus includes a support frame, a top plate fixedly mounted on the top of the support frame, a force-bearing plate mounted above the top plate, and multiple vertical force transmission rods mounted on the force-bearing plate. These force transmission rods vertically penetrate the top plate and slide within it. A tensile base is mounted at the lower end of each force transmission rod. A lower spherical head gripper, slidingly engaging with the tensile base, is mounted on the tensile base. The lower spherical head gripper has a lower clamping blind groove at its top. An upper spherical head gripper, slidingly engaging with the top plate, is mounted on the top plate. An upper clamping blind groove is located at the bottom of the upper spherical head gripper, with the centerline of the upper clamping blind groove coinciding with the centerline of the lower clamping blind groove. This ensures that the load and the center of the specimen are on the same horizontal line. (Liu Shi) [4] Laser technology was incorporated into a direct tensile testing instrument for rocks under triaxial loading. When all laser beams reach the specimen surface at equal distances, it indicates that the specimen's axis and the tensile force axis are aligned, signifying successful centering. This allows for rapid and precise centering of the specimen with the vacuum sleeve assembly. A ring-type lever clamping assembly was also added to secure the specimen; the inner diameter of the circular space can be adjusted by rotating the nut. Tensile tests were conducted on specimens under different confining pressures through the combined action of a confining pressure controller and hydraulic fluid within the flexible material. (Ding Xiaotang et al.) [5] In the direct tensile test, a simplified improvement was made to the ordinary hydraulic universal testing machine. A rigid frame consisting of a tie rod and a crossbeam was designed, and the complete tensile stress-strain curve of concrete was measured. The publicly disclosed testing device also included four 8mm steel bars as additional rigid components. To reduce the effect of eccentricity, a hinge joint was added between the specimen and the bolt-driven force transmission rod. The hinge joint consists of three parts: a hemispherical hinge with a threaded rod, a steel sleeve, and a threaded base. The hemispherical hinge can be finely adjusted under load, ensuring that the center of load application is as collinear as possible with the physical center of the specimen. (Yang Wusheng, Xue Mingxia) [6] A WAW-E600C microcomputer-controlled electro-hydraulic servo universal testing machine was designed. Computer-controlled closed-loop operation is employed. The electro-hydraulic control valves react quickly and accurately to changes in the control signals fed back from the outside, rapidly adjusting the oil inlet and outlet of the testing machine's cylinders, thus enabling the testing machine to operate precisely according to the set control parameters. When applying the load, due to gaps in the clamping and connection points of the specimen, and potential issues such as improper installation of the displacement sensor used for feedback signals, a constant load control mode is used when the specimen is initially stretched. After stabilizing the stretching, the system switches to a deformation control mode until the test ends. This prevents unexpected specimen breakage. (Pang Linge, Wang Jianguo) [7]A multi-inclination Brazilian splitting device was designed, which is symmetrical on the left and right, and the upper bearing plate has a detachable blade-shaped pressure head that can be replaced according to the experimental conditions. The two sides of the blade have two triangular grooves, which can make the rock break under concentrated force from top to bottom. The upper part of the turntable has a pointer groove, which can accurately record different inclinations. This device can realize splitting experiments at different angles, is easy to operate, and has high precision. Chen Xudong, Wang Xuyang [8] A simple tensile device for testing the tensile strength of rock was invented, which creates an area that can withstand uniform tensile stress, overcomes the eccentricity problem of existing devices, and uses the loading pad column to transmit the loading pressure to the loading pad by abutting the pad plates symmetrically distributed along the vertical axis. The tensile stress strength of the rock is obtained by splitting experiment.

[0004] Currently, the experimental configuration for directly measuring the tensile strength of brittle materials mainly includes straight tensile experiment configuration and splitting experiment configuration. In the above-mentioned schemes, one or more of the following problems still exist:

[0005] ① Most of the devices involve straight tensile experiment configuration, which is more complicated to make and requires high precision.

[0006] ② Most experimental devices involve fixed experimental component sizes, and the equipment cannot simultaneously satisfy multiple different size experimental configurations.

[0007] ③ Most of the equipment can only do static tensile experiment.

[0008] References

[0009] [1] Cao, R., Lin, Q., Cao, P., et al. A rock direct tensile experiment device and its application method [P]. Hunan Province: CN109115613A, 2019-01-01.

[0010] [2] Zhang, X., Zhang, Q., Yuan, S., et al. Development and application of rock axial direct tensile test device [J]. Chinese Journal of Rock Mechanics and Engineering, 2014, 33(12): 2517-2523. DOI:10.13722 / j.cnki.jrme.2014.12.017.

[0011] [3] He, X., Liu, J., Tang, Y., et al. Rock direct tensile test device suitable for all pressure testing machines [P]. Sichuan Province: CN218330974U, 2023-01-17.

[0012] [4] Liu, S., Wen, Z., Jiben, P. Direct tensile experiment instrument for rock under triaxial loading [P]. Shaanxi Province: CN115326574A, 2022-11-11.

[0013] [5] Ding Xiaotang, Ding Xin, Liu Haixia, Zheng Yan. Comparison of softening curve determined by concrete direct tension test and three-point bending fracture test

J

[0014] [6] Yang Wusheng, Xue Mingxia. Test method and device of concrete uniaxial tension stress-strain full curve

J

[0015] [7] Pan Gelin, Wang Jiangguo, Wang Xiaojie. A multi-inclination brazilian splitting experiment splitting device [P]. Shandong: CN206378367U, 2017-08-04.

[0016] [8] Chen Xudong, Wang Xuyang, Li Zuoyu, et al. An indirect tension device and method for testing rock tensile strength [P]. Jiangsu Province: CN113218769B, 2022-06-10. SUMMARY

[0017] Therefore, the purpose of the present application is to provide a tensile strength testing device with simple structure, reliable implementation, strong adaptability to component size, and the ability to adapt to static tension and other tension loading methods, as well as its application in single-material or double-material components.

[0018] In order to achieve the above technical purpose, the technical solution adopted by the present application is:

[0019] A tensile strength testing device for loading and fixing a test piece, comprising:

[0020] A first clamping assembly for clamping and fixing one end of the test piece;

[0021] A second clamping assembly arranged opposite to the first clamping assembly and used for clamping and fixing the other end of the test piece;

[0022] A first support connected to one end of the first clamping assembly and the second clamping assembly through a first connecting assembly;

[0023] A second support connected to the other end of the first clamping assembly and the second clamping assembly through a second connecting assembly.

[0024] Wherein, the first support and the second support can move relatively in the direction of approaching each other, so that the first connecting assembly connected to the first support and the second connecting assembly connected to the second support respectively drive the first clamping assembly and the second clamping assembly to move in the direction of moving away from each other, so that the test piece clamped on the first clamping assembly and the second clamping assembly is subjected to tension;

[0025] In addition, the first support and the second support are used for connecting or one of them is used for connecting an external force applying unit for generating a force, and when one of the first support and the second support is connected with the force applying unit, the other is connected with a supporting unit for limiting the movement of the first support or the second support along the force applying direction of the force applying unit.

[0026] As a possible implementation, further, the first clamping assembly of the present solution comprises:

[0027] A first connecting block, wherein a first through hole is arranged in the middle part;

[0028] A first expansion module, arranged in the first through hole, and a first expansion area is formed in the middle part of the first expansion module;

[0029] A plurality of first clamping blocks are arranged in the first expansion area in a ring array, and a first clamping area adapted to the contour of one end of the test piece is formed between the plurality of first clamping blocks. The side wall of the first expansion module is close to the plurality of first clamping blocks, and the plurality of first clamping blocks are driven by the first expansion module to fold on each other, so as to clamp the test piece in the first clamping area.

[0030] As a preferred implementation, the second clamping assembly of the present solution comprises:

[0031] A second connecting block, wherein a second through hole is arranged in the middle part, and one of the end faces of the second connecting block corresponding to the second through hole is opposite to one of the end faces of the first connecting block corresponding to the first through hole;

[0032] A second expansion module, arranged in the second through hole, and a second expansion area is formed in the middle part of the second expansion module;

[0033] A plurality of second clamping blocks are arranged in the second expansion area in a ring array, and a second clamping area adapted to the contour of the other end of the test piece is formed between the plurality of second clamping blocks. The side wall of the second expansion module is close to the plurality of second clamping blocks, and the plurality of second clamping blocks are driven by the second expansion module to fold on each other, so as to clamp the test piece in the second clamping area.

[0034] As a preferred implementation, the first expansion module and the second expansion module of the present solution are both expansion sleeves.

[0035] As a preferred implementation, the first clamping block and the second clamping block of the present solution are both arc-shaped blocks, and the outer peripheral contour of the plurality of first clamping blocks and the plurality of second clamping blocks after being enclosed is a circle adapted to the inner ring contour of the expansion sleeve.

[0036] As a preferred implementation selection, preferably, the first clamping area formed by the plurality of first clamping blocks and the second clamping area formed by the plurality of second clamping blocks are rectangular or circular.

[0037] As a preferred implementation selection, preferably, the first connecting block is provided with a pair of first protrusions opposite to each other on the end face close to the second connecting block, the second connecting block is provided with a pair of second protrusions opposite to each other on the end face close to the first connecting block, and the first protrusions are in contact with the side walls of the second protrusions when the first connecting block and the second connecting block are in contact.

[0038] As a preferred implementation selection, preferably, the first support is a cylindrical structure with one end closed, and the first connecting components include a first connecting rod and a second connecting rod, wherein one end of the first connecting rod and the second connecting rod is rotatably connected between a pair of first connecting parts, one end of the first connecting block is provided with a second connecting part, one end of the second connecting block is provided with a third connecting part, the other end of the first connecting rod is rotatably connected with the second connecting part, and the other end of the second connecting rod is rotatably connected with the third connecting part.

[0039] As a preferred implementation selection, preferably, the second support is a plate-shaped structure, and the second connecting components include a third connecting rod and a fourth connecting rod, wherein one end of the third connecting rod and the fourth connecting rod is rotatably connected between a pair of fourth connecting parts, the other end of the first connecting block is provided with a fifth connecting part, the other end of the second connecting block is provided with a sixth connecting part, the other end of the third connecting rod is rotatably connected with the fifth connecting part, and the other end of the fourth connecting rod is rotatably connected with the sixth connecting part.

[0040] As a preferred implementation selection, preferably, the number of the second connecting rod and the fourth connecting rod is a pair, one end of the first connecting rod is located between one end of the pair of second connecting rods, and one end of the third connecting rod is located between one end of the pair of fourth connecting rods; the number of the second connecting part is a pair and is oppositely arranged, the other end of the first connecting rod is rotatably connected between a pair of second connecting parts, and the other end of the second connecting rod is rotatably connected on both sides of the third connecting part.

[0041] As a preferred implementation selection, preferably, the number of the fifth connecting part is a pair and is oppositely arranged, the other end of the third connecting rod is rotatably connected between a pair of fifth connecting parts, and the other end of the fourth connecting rod is rotatably connected on both sides of the sixth connecting part.

[0042] The first connecting rod, the second connecting rod, the third connecting rod and the fourth connecting rod are all rotationally connected with the corresponding first connecting part, second connecting part, third connecting part, fourth connecting part, fifth connecting part and sixth connecting part through a cylindrical pin.

[0043] Based on the above, the present application also provides a single material or double material component tensile test system, which comprises the tensile strength test device described above, and further comprises at least one force applying unit, which is used to actively output acting force and is connected with a force measuring unit for collecting the size of the acting force;

[0044] The first support and the second support of the tensile strength test device are both connected with the force applying unit, and the first support and the second support are relatively moved in the direction of approaching each other by the power provided by the force applying unit; when one of the first support and the second support is connected with the force applying unit, the other is connected with a supporting unit for limiting the movement of the first support or the second support in the direction of the acting force of the force applying unit;

[0045] In addition, the test piece is a single material or double material component.

[0046] By adopting the technical scheme described above, the present application has the beneficial effects compared with the prior art: the present scheme ingeniously connects the first clamping assembly and the second clamping assembly with the first support and the second support through the connecting assembly (the first connecting assembly and the second connecting assembly) to form a tensile strength test device, so that after the first support and / or the second support is connected with the force applying unit for generating acting force, the acting force can be provided by the force applying unit to relatively move the first support and the second support in the direction of approaching each other, so that the first connecting assembly connected with the first support and the second connecting assembly connected with the second support respectively drive the first clamping assembly and the second clamping assembly to move in the direction of moving away from each other, so that the test piece clamped on the first clamping assembly and the second clamping assembly is subjected to tension, thereby completing the tension application and realizing the tensile test of the test piece; the connecting assembly is connected with the support and the connecting block in the form of connection, which not only has a flexible structure but also can assist in calculating the horizontal tension of the test piece by the angle of the connecting rod and the angle of the impact force or static pressure applied by the force applying unit, thereby providing convenient assistance for subsequent experimental calculation; at the same time, the device of the present scheme can make the stress distribution of the middle tension area of the test piece similar to that in the traditional straight tensile experiment, i.e. only tensile stress exists in the tension area; and the device can realize the straight tensile failure under static load and impact, in addition, the device cooperates the clamping block by the tightness of the expansion module to clamp test pieces of different sizes, which not only has flexible operation but also has good test piece adaptability, thereby facilitating the operation of the experimental personnel, improving the experimental efficiency and applicability. BRIEF DESCRIPTION OF DRAWINGS

[0047] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description only show some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without any creative effort.

[0048] Figure 1 is a three-dimensional perspective view of a brief implementation structure of the device of the present application scheme;

[0049] Figure 2 is a three-dimensional perspective view of a brief implementation structure of the device of the present application scheme;

[0050] Figure 3 is a two-dimensional cutaway perspective view of a brief implementation structure of the device of the present application scheme;

[0051] Figure 4 is an exploded view of a brief implementation structure of the device of the present application scheme;

[0052] Figure 5 is a cooperation schematic view of a first support and a first connecting assembly of the device of the present application scheme;

[0053] Figure 6 is a cooperation schematic view of a first support and a first connecting assembly of the device of the present application scheme;

[0054] Figure 7 is a cooperation schematic view of a second support and a second connecting assembly of the device of the present application scheme;

[0055] Figure 8 is a cooperation schematic view of a second support and a second connecting assembly of the device of the present application scheme;

[0056] Figure 9 is a structural schematic view of a first expansion module or a second expansion module of the device of the present application scheme;

[0057] Figure 10 is a schematic view of the device of the present application scheme in which the first expansion module and the second expansion module cooperate with the first clamping block and the second clamping block to clamp and fix the test piece;

[0058] Figure 11 is a three-dimensional cutaway perspective view of a brief implementation structure of the device of the present application scheme when clamping a test piece;

[0059] Figure 12 is a schematic view of the device of the present application scheme cooperating with the force applying unit and the supporting unit after clamping a test piece;

[0060] Figure 13is a brief force diagram of the device of the present application scheme after clamping the test piece, which cooperates with the force applying unit and the supporting unit to stretch the test piece;

[0061] Figure 14 is a schematic diagram of four kinds of test pieces applicable to the device of the present application scheme, wherein (a) and (c) are single-material test pieces, and (b) and (d) are double-material test pieces. DETAILED DESCRIPTION

[0062] The present application will be further described in conjunction with the accompanying drawings and examples. It is particularly pointed out that the following examples are only used to illustrate the present application, but do not limit the scope of the present application. Similarly, the following examples are only part of the embodiments of the present application, not all embodiments, and all other embodiments obtained by those skilled in the art without creative labor are within the scope of the present application.

[0063] As Figures 1 to 12 The present embodiment is a tensile strength testing device for loading and fixing a test piece 8, which comprises:

[0064] A first clamping assembly 1 is used to clamp and fix one end of the test piece 8;

[0065] A second clamping assembly 2 is arranged opposite to the first clamping assembly 1 and is used to clamp and fix the other end of the test piece 8;

[0066] A first support 3 is connected to one end of the first clamping assembly 1 and the second clamping assembly 2 through a first connecting assembly 4;

[0067] A second support 5 is connected to the other end of the first clamping assembly 1 and the second clamping assembly 2 through a second connecting assembly 6.

[0068] The first support 3 and the second support 5 can move relative to each other in a direction of approaching each other, so that the first connecting assembly 4 connected to the first support 3 and the second connecting assembly 6 connected to the second support 5 respectively drive the first clamping assembly 1 and the second clamping assembly 2 to move in a direction of moving away from each other, so that the test piece 8 clamped on the first clamping assembly 1 and the second clamping assembly 2 is subjected to tension;

[0069] In addition, when the device of the present application scheme is used, the first support 3 and the second support 5 are used to connect or one of them is used to connect an external force applying unit 9 for generating force, and when one of the first support 3 and the second support 5 is connected with the force applying unit 9, the other is connected with a supporting unit 10 for limiting the movement of the first support 3 or the second support 5 in the direction of the force applying unit 9.

[0070] In other words, in the device of the present solution, the first support 3 and the second support 5 can be connected to the force applying unit 9 for actively applying force, or alternatively, one of them is connected to the force applying unit 9 for actively applying force, and the other is connected to the supporting unit 10, so that when the force applying unit 9 applies external force, the first support 3 and the second support 5 can be relatively moved in the direction of approaching each other, finally driving the first clamping assembly 1 and the second clamping assembly 2 to move in the direction of moving away from each other, so that the test piece 8 clamped on the first clamping assembly 1 and the second clamping assembly 2 is subjected to tension to perform tensile strength test.

[0071] As for the clamping assembly, the first clamping assembly 1 of the present solution comprises:

[0072] The first connecting block 11 is provided with a first through hole 111 in the middle;

[0073] The first expansion module 12 is arranged in the first through hole 111 and has a first expansion area 121 in the middle;

[0074] The first clamping block 13 is arranged in the first expansion area 121 in a ring array, and a plurality of first clamping blocks 13 are arranged to form a first clamping area 131 in the first expansion area 121, which is adapted to the contour of one end of the test piece 8. The side wall of the first clamping block 13 close to the first expansion module 12 is attached to the first expansion module 12, and the first clamping block 13 is driven by the first expansion module 12 to fold towards each other, so as to clamp the test piece 8 in the first clamping area 131.

[0075] As a preferred embodiment, the second clamping assembly 2 of the present solution comprises:

[0076] The second connecting block 21 is provided with a second through hole 211 in the middle, and one of the end faces of the second connecting block 21 corresponding to the second through hole 211 is opposite to one of the end faces of the first connecting block 11 corresponding to the first through hole 111;

[0077] The second expansion module 22 is arranged in the second through hole 211 and has a second expansion area 221 in the middle;

[0078] The second clamping block 23 is arranged in the second expansion area 221 in a ring array, and a plurality of second clamping blocks 23 are arranged to form a second clamping area 231 in the second expansion area 221, which is adapted to the contour of the other end of the test piece 8. The side wall of the second clamping block 23 close to the second expansion module 22 is attached to the second expansion module 22, and the second clamping block 23 is driven by the second expansion module 22 to fold towards each other, so as to clamp the test piece 8 in the second clamping area 231.

[0079] As an example of selection, the first expansion module 12 and the second expansion module 22 are both expansion sleeves, which can be Z2 type expansion sleeves. In addition, the first expansion module 12 and the second expansion module 22 can be detachably fixed on the first connecting block 11 and the second connecting block 22, so that the test personnel can select different specifications of expansion modules according to needs, and conveniently clamp different specifications of test pieces.

[0080] In addition, in order to more conveniently adjust the clamping space of the test piece 8, as a preferred embodiment, the first clamping block 13 and the second clamping block 23 are arc-shaped blocks, and the outer periphery profile of the plurality of first clamping blocks 13 and the plurality of second clamping blocks 23 after being enclosed is circular and adapted to the inner ring profile of the expansion sleeve. Through this structure, the clamping block can better cooperate with the inner ring of the expansion module, and the contact surface is improved, and the clamping reliability is increased.

[0081] In addition, for test pieces 8 with different cross-sectional shapes, as a preferred embodiment, the first clamping area 131 formed by the plurality of first clamping blocks 13 after being enclosed and the second clamping area 231 formed by the plurality of second clamping blocks 23 after being enclosed are rectangular or circular, and can also be other profiles adapted to the test piece 8.

[0082] Since the first connecting block 11 and the second connecting block 21 move in the direction away from each other under stress to provide tensile force, in order to avoid dislocation of the first connecting block 11 and the second connecting block 21 during relative movement and improve the movement guiding reliability, as a preferred embodiment, the first connecting block 11 is provided with a pair of first protrusions 16 opposite in up and down on the end face close to the second connecting block 21, and the second connecting block 21 is provided with a pair of second protrusions 26 opposite in up and down on the end face close to the first connecting block 11 corresponding to the first protrusions 16, and when the first connecting block 11 and the second connecting block 21 are in relative contact, the first protrusions 16 are attached to the side walls of the second protrusions 26, that is, the pair of first protrusions 16 and the pair of second protrusions 26 are sliding guides to each other.

[0083] In the embodiment of the support and the connecting assembly, the first support 3 is a closed-end cylindrical structure, and first connecting parts 31 are arranged on both sides of the closed end; the first connecting assembly 4 comprises first connecting rods 41 and second connecting rods 42, wherein one end of the first connecting rods 41 and the second connecting rods 42 is rotatably connected between a pair of first connecting parts 31, one end of the first connecting block 11 is provided with a second connecting part 14, one end of the second connecting block 21 is provided with a third connecting part 24, the other end of the first connecting rod 41 is rotatably connected with the second connecting part 14, and the other end of the second connecting rod 42 is rotatably connected with the third connecting part 24.

[0084] The second support 5 is a plate structure, and fourth connecting parts 51 are arranged on both sides of one end surface; the second connecting assembly 6 comprises third connecting rods 61 and fourth connecting rods 62, wherein one end of the third connecting rods 61 and the fourth connecting rods 62 is rotatably connected between a pair of fourth connecting parts 51, the other end of the first connecting block 11 is provided with a fifth connecting part 15, the other end of the second connecting block 21 is provided with a sixth connecting part 25, the other end of the third connecting rod 61 is rotatably connected with the fifth connecting part 15, and the other end of the fourth connecting rod 62 is rotatably connected with the sixth connecting part 25.

[0085] The connecting assembly is composed of connecting rods, which can provide flexible and reliable force transmission for the connection of the first support 3, the second support 5, the first clamping assembly 1 and the second clamping assembly 2. Meanwhile, the connecting assembly is a flexible and movable component, which is convenient to adjust and install, and can greatly facilitate the on-site assembly or maintenance or factory pre-assembly of the experimental device.

[0086] In order to improve the connection reliability of the connecting assembly and provide stable transmission force for the support and the connecting block, in the present application, as a preferred embodiment, preferably, the number of the second connecting rods 42 and the fourth connecting rods 62 is one pair, one end of the first connecting rod 41 is located between one end of the pair of second connecting rods 42, and one end of the third connecting rod 61 is located between one end of the pair of fourth connecting rods 62; the number of the second connecting parts 14 is one pair and is oppositely arranged, the other end of the first connecting rod 41 is rotatably connected between the pair of second connecting parts 14, and the other end of the second connecting rod 42 is rotatably connected on both sides of the third connecting part 24. The number of the fifth connecting parts 15 is one pair and is oppositely arranged, the other end of the third connecting rod 61 is rotatably connected between the pair of fifth connecting parts 15, and the other end of the fourth connecting rod 62 is rotatably connected on both sides of the sixth connecting part 25.

[0087] The first connecting rod 41, the second connecting rod 42, the third connecting rod 61 and the fourth connecting rod 62 are all rotationally connected with the corresponding first connecting part 31, the second connecting part 14, the third connecting part 24, the fourth connecting part 51, the fifth connecting part 15 and the sixth connecting part 25 through the cylindrical pin 7; in order to improve the connection reliability of the cylindrical pin 7, the connecting hole is correspondingly arranged on the connecting part, and then the cylindrical pin 7 is fixed on the corresponding connecting part by penetrating the fixing rod 71, so that the abnormal condition that the connecting rod is out of the cylindrical pin 7 or is obviously displaced when rotating around the cylindrical pin 7 is prevented.

[0088] The fourth connecting part 51 can be detachably fixed and installed on the second support 5 by bolts, or can be welded or in other forms.

[0089] Based on the above, the device of the embodiment can also be used in a single-material or double-material component tensile test system, which comprises the aforementioned tensile strength test device, and further comprises at least one force applying unit 9, which is used to actively output acting force and is connected with a force measuring unit for collecting the size of the acting force.

[0090] The first support 3 and the second support 5 of the tensile strength test device are connected with or one of them is connected with the force applying unit 9, and the power for the relative movement of the first support 3 and the second support 5 in the direction of approaching each other is provided by the force applying unit 9; when one of the first support 3 and the second support 5 is connected with the force applying unit 9, the other is connected with a support unit 10 for limiting the movement of the first support 3 or the second support 5 in the direction of the acting force of the force applying unit 9; in addition, the test piece 8 is a single-material or double-material component.

[0091] For the force applying unit 9, when the test device of the embodiment is loaded on the Hopkinson pressure bar system, the first support 3 can be installed in cooperation with the incident bar of the Hopkinson pressure bar system, and the threaded hole 32 on the cylindrical structure of the first support 3 can be further locked and fixed when the first support 3 is sleeved on the incident bar; the second support 5 can be cooperated with the transmission bar of the Hopkinson pressure bar system, that is, the transmission bar is used as the support unit 10, and then the acting force of the impact bar of the Hopkinson pressure bar system is transmitted to the test device. However, the force applying unit 9 cooperated with the test device of the embodiment is not limited to this, and it can be other devices that can provide active acting force and supporting force. In the measurement of the acting force, the existing force measuring device can be used to assist in obtaining the relevant acting force data, which will not be described here.

[0092] Based on the combination of the Figures 1 to 12 , further based on the combination of Figure 13As shown, the tensile strength testing device can calculate the horizontal tension of the test piece by the angle of the connecting rods (the first, second, third and fourth connecting rods) and the size of the impact force or static pressure (the force exerted by the force exerting unit 9, which can be obtained by the force measuring device) when the force exerting unit 9 acts.

[0093] In combination Figure 13 It can be seen that when the force F is transmitted to the first support 3 and the first connecting assembly 4, F is decomposed into F1 and F2. When the first connecting rod 41 and the second connecting rod 42 of the first connecting assembly 4 are reached, the horizontal force F can be obtained according to the sine and cosine function values of the included angle of the two rods. 1h The horizontal force is the tensile force corresponding to the test piece, and the calculation formula is as follows:

[0094] F 1h = F1 x cos ∠2

[0095] And the tensile force of the test piece can be calculated by the following formula:

[0096] F h = 2 x F 1h .

[0097] In this scheme, the structure of the test piece can be various, Figure 14 Four kinds of test piece implementation structures are shown, wherein (a) and (c) are single material test pieces, and (b) and (d) are double material test pieces.

[0098] The above only describes some embodiments of the present application, and does not limit the protection scope of the present application, and any equivalent device or equivalent process transformation obtained by using the content of the present application specification and drawings, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A tensile strength testing device for the loading and securing of a piece to be tested, characterized in that, It comprises: A first clamping assembly for clamping and fixing one end of the test piece; A second clamping assembly arranged opposite to the first clamping assembly and used for clamping and fixing the other end of the test piece; A first support connected to one end of the first clamping assembly and the second clamping assembly through a first connecting assembly; A second support connected to the other end of the first clamping assembly and the second clamping assembly through a second connecting assembly; Wherein, the first support and the second support can move relatively in the direction of approaching each other, so that the first connecting assembly connected by the first support and the second connecting assembly connected by the second support drive the first clamping assembly and the second clamping assembly to move in the direction of moving away from each other respectively, so that the test piece clamped on the first clamping assembly and the second clamping assembly is subjected to tension; The first support and the second support are used for connecting or one of them is used for connecting an external force applying unit for generating acting force, when one of the first support and the second support is connected with the force applying unit, the other is connected with a supporting unit for limiting the movement of the first support or the second support in the direction of the acting force of the force applying unit; The first clamping assembly comprises: A first connecting block having a first through hole in the middle; A first expansion module arranged in the first through hole and having a first expansion area in the middle; A plurality of first clamping blocks arranged in a ring array in the first expansion area, the plurality of first clamping blocks form a first clamping area adapted to the contour of one end of the test piece, and the side walls of the plurality of first clamping blocks close to the first expansion module are attached to the first expansion module, so that the plurality of first clamping blocks are driven by the first expansion module to fold towards each other, clamping the test piece in the first clamping area; The second clamping assembly comprises: A second connecting block having a second through hole in the middle, and one of the end faces of the second connecting block corresponding to the second through hole is opposite to one of the end faces of the first connecting block corresponding to the first through hole; A second expansion module arranged in the second through hole and having a second expansion area in the middle; A plurality of second clamping blocks arranged in a ring array in the second expansion area, the plurality of second clamping blocks form a second clamping area adapted to the contour of the other end of the test piece, and the side walls of the plurality of second clamping blocks close to the second expansion module are attached to the second expansion module, so that the plurality of second clamping blocks are driven by the second expansion module to fold towards each other, clamping the test piece in the second clamping area; The first support is a closed cylindrical structure, and the closed ends of the first support are provided with first connecting parts opposite to each other; The first connecting assembly comprises a first connecting rod and a second connecting rod, wherein one end of the first connecting rod and the second connecting rod is rotatably connected between a pair of first connecting parts, one end of the first connecting block is provided with a second connecting part, one end of the second connecting block is provided with a third connecting part, the other end of the first connecting rod is rotatably connected with the second connecting part, and the other end of the second connecting rod is rotatably connected with the third connecting part; The second support is a plate structure, and the two sides of one end face of the second support are provided with fourth connecting parts opposite to each other; The second connecting assembly comprises a third connecting rod and a fourth connecting rod, one end of the third connecting rod and the fourth connecting rod is rotatably connected between a pair of fourth connecting parts, the other end of the first connecting block is provided with a fifth connecting part, the other end of the second connecting block is provided with a sixth connecting part, the other end of the third connecting rod is rotatably connected with the fifth connecting part, and the other end of the fourth connecting rod is rotatably connected with the sixth connecting part.

2. The tensile strength testing device of claim 1, wherein, The first expansion module and the second expansion module are expansion sleeves.

3. The tensile strength testing device of claim 2, wherein, The first clamping block and the second clamping block are arc-shaped blocks, and the outer circumferential profile of the plurality of first clamping blocks and the plurality of second clamping blocks after being enclosed is circular and adapted to the inner ring profile of the expansion sleeve.

4. The tensile strength testing device of claim 3, wherein, The first clamping area formed after the plurality of first clamping blocks are enclosed and the second clamping area formed after the plurality of second clamping blocks are enclosed are rectangular or circular.

5. A tensile strength testing device as claimed in any one of claims 1 to 4, wherein, A pair of first protrusions opposite in up and down direction are arranged on the end face of the first connecting block close to the second connecting block, a pair of second protrusions opposite in up and down direction are arranged on the end face of the second connecting block close to the first connecting block corresponding to the first protrusions, and the first protrusions are in contact with the side walls of the second protrusions when the first connecting block and the second connecting block are in contact.

6. The tensile strength testing apparatus of claim 5, wherein, The number of the second connecting rod and the fourth connecting rod is one pair, one end of the first connecting rod is located between one end of the pair of second connecting rods, and one end of the third connecting rod is located between one end of the pair of fourth connecting rods; the number of the second connecting part is one pair and is oppositely arranged, the other end of the first connecting rod is rotatably connected between the pair of second connecting parts, and the other end of the second connecting rod is rotatably connected on both sides of the third connecting part; The number of the fifth connecting part is one pair and is oppositely arranged, the other end of the third connecting rod is rotatably connected between the pair of fifth connecting parts, and the other end of the fourth connecting rod is rotatably connected on both sides of the sixth connecting part; The first connecting rod, the second connecting rod, the third connecting rod and the fourth connecting rod are rotatably connected with the corresponding first connecting part, the second connecting part, the third connecting part, the fourth connecting part, the fifth connecting part and the sixth connecting part through a cylindrical pin.

7. A single or dual material component tensile testing system characterized by, The tensile strength testing device comprises at least one force applying unit for actively outputting a force, and a force measuring unit connected to the force applying unit for collecting the size of the force; The first support and the second support of the tensile strength testing device are connected with the force applying unit, and the first support and the second support are driven to move in the direction of approaching each other by the force applying unit; when one of the first support and the second support is connected with the force applying unit, the other is connected with a support unit for limiting the movement of the first support or the second support in the direction of the force applied by the force applying unit; In addition, the test piece is a single-material or double-material component.

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