A biaxial tensile-shear loading test fixture compatible with multiple connection forms

Abstract

The present invention discloses a biaxial tension-shear loading test fixture that can be compatible with multiple connection forms, including: two pairs of upper and lower porous loading disks, which are arranged oppositely. The porous loading disks are quarter-circular structures and have rectangular notches at the centers; a plurality of loading angle holes, which are arranged at intervals along the circumferences of the porous loading disks; two loading arms, one ends of which are arranged between the two spaced porous loading disks; two sets of pin connection systems, which detachably connect the loading arms to the porous loading disks; two specimen mounting mechanisms, which are arranged oppositely; a plurality of disk fastening systems, which detachably connect the specimen mounting mechanisms to the porous loading disks; a specimen mechanism, which includes two three-leaf specimens. After the two specimens are relatively selected by 60° with the structural center as the origin, they are fixed at the center; a plurality of specimen fastening systems, which detachably connect the specimen mechanism to the specimen mounting mechanisms. It can freely control the tension-shear ratio of the applied load according to actual needs.

Description

Technical Field

[0001] The present invention relates to a biaxial tensile-shear loading test fixture that can be compatible with multiple connection forms, and belongs to the technical field of mechanical property testing of materials and structures. Background Art

[0002] In the current field of body manufacturing processes, the application of composite materials such as aluminum alloys, magnesium alloys, and carbon fiber has been very extensive, which has put forward higher requirements for the strength and reliability of the connection forms between components. In addition to the traditional resistance spot welding process, many new connection processes have emerged, such as Self-piercing Riveting, Clinching, Flow Drill Screws, etc. The working scenarios of vehicles also determine that body components are mostly in a complex stress state of multi-stresses. Especially under the tensile-shear coupling stress, stress concentration may occur in the spot connection form, which may lead to deformation, fracture, fatigue, etc. Therefore, how to accurately measure the mechanical properties such as strength, failure mode, and fatigue characteristics of the spot connection form between various materials under the combined action of tensile-shear stress is of great significance for the selection and optimization of the spot connection form.

[0003] The Arcan fixture is widely used in the field of material testing and is often used to obtain the stress state in any plane to study the failure mechanism of materials under different stress states. And through different loading forms, different tensile-shear ratio loadings of material components can also be achieved. With the rise of composite materials and material bonding technologies, the application field of the Arcan fixture has been further extended to the mechanical property analysis of composite materials or bonding interfaces under biaxial loading, especially in fields where composite materials and bonding technologies are widely applied such as vehicles and aviation.

[0004] Aiming at the actual application scenarios of the current body manufacturing processes, the existing Arcan fixtures have certain limitations:

[0005] 1. Currently, conventional Arcan fixtures generally use standard specimens to test the stress states of different materials or bonding interface layers. However, for the spot connection forms such as spot welding, spot bonding, and riveting commonly used in body processes, the two components using this connection form are usually relatively thin, and it is difficult for the standard specimens of the current Arcan fixtures to be compatible with such connection forms.

[0006] 2. During the process of using the Arcan fixture to conduct a tensile-shear test on the connection interface of two components, the phenomenon of loading deviation may occur due to uneven connection distribution, which may lead to a large error in the test results. Summary of the Invention

[0007] The present invention designs and develops a biaxial tensile-shear loading test fixture that can be compatible with multiple connection forms and can freely control the tensile-shear ratio of the applied load according to actual needs.

[0008] Another object of the present invention: It can be compatible with multiple connection forms and test the biaxial tensile-shear characteristics of the connection forms.

[0009] The technical solution provided by the present invention is as follows:

[0010] A biaxial tensile-shear loading test fixture that can be compatible with multiple connection forms, comprising:

[0011] Two pairs of upper and lower porous loading disks, which are arranged oppositely. In each pair of porous loading disks, the two porous loading disks are arranged at intervals. The porous loading disk is a quarter-circular structure and has a rectangular notch at the center;

[0012] A plurality of loading angle holes, which are arranged at intervals along the circumference of the porous loading disk;

[0013] Two loading arms, one end of which is arranged between the two porous loading disks arranged at intervals;

[0014] Two groups of pin connection systems, one end of which passes through the loading angle holes and the loading arms to detachably connect the loading arms to the porous loading disks;

[0015] Two specimen mounting mechanisms, which are arranged oppositely, and one end of the specimen mounting mechanism is arranged between the two porous loading disks arranged at intervals;

[0016] A plurality of disk fastening systems, one end of which passes through the porous loading disk and one end of the specimen mounting mechanism to detachably connect the specimen mounting mechanism to the porous loading disk;

[0017] A specimen mechanism, which includes two three-leaf specimens. After the two specimens rotate 60° relative to each other with the structural center as the origin, they are point-connected at the center; the two specimens are respectively arranged at the other ends of the two specimen mounting mechanisms;

[0018] A plurality of specimen fastening systems, one end of which passes through the other end of the specimen mounting mechanism and the specimen to detachably connect the specimen to the specimen mounting mechanism.

[0019] Preferably, it further includes:

[0020] A plurality of first nut mounting grooves, which are regular hexagon structures and are concentrically arranged with the plurality of loading angle holes and are located on one of the porous loading disks in each pair of porous loading disks;

[0021] A loading arm pin hole, which is arranged at one end of the loading arm;

[0022] The loading arm connecting pin has a regular hexagon at one end and is arranged to match the first nut installation groove; an annular groove is arranged circumferentially at the other end of the loading arm connecting pin;

[0023] The connecting pin circlip is of a C-shaped structure and is arranged to match the annular groove;

[0024] Wherein, the loading arm pin hole is arranged to match the loading angle hole, and the other end of the loading arm connecting pin passes through the loading angle hole and the loading arm pin hole and is positioned by the connecting pin circlip arranged in the annular groove;

[0025] The loading arm mounting hole is opened on the side of the other end of the loading arm.

[0026] Preferably, the specimen has 3 circular ends and is provided with first specimen mounting holes thereon.

[0027] Preferably, the fixing method between the two specimens is at least one of welding, riveting, bolt connection, and bonding.

[0028] Preferably, it further includes:

[0029] The first specimen mounting arm hole is opened on the porous loading disc and is close to the rectangular notch;

[0030] Wherein, on each porous loading disc, the number of the first specimen mounting arm holes is at least two.

[0031] Preferably, the specimen mounting mechanism includes:

[0032] The specimen mounting arm is of a rectangular body structure, and at least two second specimen mounting arm holes are opened at one end thereof;

[0033] The specimen mounting table is fixedly arranged at the other end of the specimen mounting arm;

[0034] The specimen mounting table has the same shape as the specimen, and a specimen connection groove is opened in the middle of the specimen mounting table, and second specimen mounting holes are respectively opened on the circular ends of the specimen mounting table.

[0035] Preferably, a second nut installation groove is concentrically arranged with the first specimen mounting arm hole, and it has the same structure as the first nut installation groove and is located on the same porous loading disc.

[0036] Preferably, the disc fastening system includes: disc bolts, disc nuts, and disc fastening washers;

[0037] One end of the disc bolt passes through the first specimen mounting arm hole and the second specimen mounting arm hole and is fixed by the disc nut. The disc fastening gasket is located between the disc bolt and the porous loading disc, and the disc nut is arranged in the second nut mounting groove.

[0038] Preferably, the specimen fastening system includes a specimen bolt, a specimen nut, and a specimen fastening gasket that are matched and arranged;

[0039] One end of the specimen bolt passes through the first specimen mounting hole and the second specimen mounting hole in sequence and is fixed by the specimen nut;

[0040] The specimen fastening gasket is arranged between the specimen bolt and the specimen mounting table.

[0041] Preferably, the number of the loading angle holes is 13, and the angles between the loading angle holes and the vertical direction are in sequence: 0°, 7.5°, 15°, 22.5°, 30°, 37.5°, 45°, 52.5°, 60°, 67.5°, 75°, 82.5°, 90°.

[0042] The beneficial effects of the present invention are as follows:

[0043] 1. The three-leaf specimen of the present device has a simple structure, is convenient to process, and can be well compatible with the component point connection forms commonly used in the field of body manufacturing processes, such as spot welding, riveting, etc.;

[0044] 2. The proposed biaxial tensile-shear loading test method of the present device can realize the strength test of the connection form under complex tensile-shear working conditions, and through the thickness adjustment gasket, it can effectively prevent the loading center offset phenomenon caused by the inconsistent thickness of the two three-leaf specimens;

[0045] 3. The test fixture of the present device is reasonably designed, the overall structure is convenient to process, and each part of the fixture is connected by standard bolts, and the installation and disassembly are simple. Description of the Drawings

[0046] Figure 1 It is a three-dimensional structure schematic diagram of the biaxial tensile-shear loading test fixture that can be compatible with multiple connection forms according to the present invention.

[0047] Figure 2 It is an exploded view of the biaxial tensile-shear loading test fixture that can be compatible with multiple connection forms according to the present invention.

[0048] Figure 3 It is a three-dimensional connection schematic diagram of the three-leaf specimen in the present invention.

[0049] Figure 4 It is a schematic diagram of the loading angle holes of the porous loading disc and a schematic diagram of the force on the specimen in the present invention.

[0050] Figure 5(a) is a sectional view of a three-leaf specimen using a spot welding connection form in the present invention.

[0051] Figure 5(b) is a sectional view of a three-leaf specimen using a rivet connection form in the present invention.

[0052] Figure 5(c) is a sectional view of a three-leaf specimen using an adhesive point connection form in the present invention.

[0053] Loading arm 1, loading arm mounting hole 1a, loading arm pin hole 1b, multi-hole loading disk one 2, multi-hole loading disk two 21, loading angle hole 2a, first nut mounting groove 2b, hole one 201, hole two 202, hole three 203, hole four 204, hole five 205, hole six 206, hole seven 207, hole eight 208, hole nine 209, hole ten 210, hole eleven 211, hole twelve 212, hole thirteen 213, hole fourteen 214, hole fifteen 215, hole sixteen 216, hole seventeen 217, hole eighteen 218, hole nineteen 219, hole twenty 220, hole twenty-one 221, hole twenty-two 222, hole twenty-three 223, hole twenty-four 224, hole twenty-five 225, hole twenty-six 226, first specimen mounting arm hole 2c, disk fastening system 3, disk bolt 31, disk nut 32, disk fastening gasket 33, specimen mounting mechanism 4, specimen mounting arm 41, specimen mounting table 42, third nut mounting groove 4a, second specimen mounting hole 4b, specimen connection groove 4c, second specimen mounting arm hole 4d, three-leaf specimen 5, first specimen mounting hole 5a, spot weld 51, rivet joint 52, adhesive point 53, specimen fastening system 6, specimen bolt 61, specimen nut 62, specimen fastening gasket 63, pin connection system 7, loading arm connection pin 71, connection collar 72, annular groove 7a, thickness adjustment piece 8, thickness adjustment gasket mounting hole 8a, gasket hole 8b. Detailed implementation manners

[0054] The following further describes the present invention in detail with reference to the accompanying drawings, so that those skilled in the art can implement it according to the description in the specification.

[0055] As Figure 1 shown in -5, the present invention provides a biaxial tensile-shear loading test fixture compatible with multiple connection forms, including: loading arm 1, multi-hole loading disk 2, disk fastening system 3, specimen mounting mechanism 4, three-leaf specimen 5, specimen fastening system 6, pin connection system 7, and thickness adjustment gasket 8.

[0056] Two pairs of upper and lower porous loading disks are arranged oppositely. Each pair of porous loading disks includes a porous loading disk one 2 and a porous loading disk two 21 which are arranged at intervals. On the porous loading disk one 2 and the porous loading disk two 21, a plurality of loading angle holes 2a are arranged circumferentially. One ends of two loading arms 1 are respectively arranged between two spaced porous loading disks one 2 and porous loading disks two 21, and are fixed and detachably connected through two groups of pin connection systems 7. Two specimen mounting mechanisms 4 are arranged oppositely. Among them, one end of the specimen mounting mechanism 4 is arranged between the porous loading disk one 2 and the porous loading disk 21, and is fixed and detachably connected through a disk fastening system 3. The specimen mechanism includes two three-leaf specimens 5. After the two three-leaf specimens 5 rotate 60° relative to each other with the structural center as the origin, they are fixed at the center. The two specimens 5 are respectively arranged at the other ends of the two specimen mounting mechanisms 4, and are fixed and detachably connected through a specimen fastening system 6.

[0057] The porous loading disk one 2 and the porous loading disk two 21 respectively clamp and install a loading arm 1 and a specimen mounting mechanism 4 through two groups of disk fastening systems 3 and one group of pin connection systems 7; the two three-leaf specimens 5 are connected in the required connection form to form an integral body, and are clamped and installed through six groups of specimen fastening systems 6 and the specimen mounting mechanism 4; if the thicknesses of the two three-leaf specimens 5 are inconsistent, several thickness adjustment gaskets 8 can be added between the three-leaf specimens 5 and the specimen mounting mechanism 4, and then installed through the specimen fastening system 6.

[0058] In the present invention, as a preference, the loading arm 1 is of a rectangular body structure. One end of the loading arm 1 is provided with a through-type loading arm pin hole 1b for assembling with the loading angle hole 2a on the porous loading disk one 2, and the other end is provided with a through-type loading arm mounting hole 1a for cooperating with an additional material testing machine for load application.

[0059] The outer edge shapes of the porous loading disk one 2 and the porous loading disk two 21 are arc-shaped, and the whole is approximately a quarter of a circle, and a rectangular notch is arranged near the center of the circle as the installation space for the specimen mounting mechanism 4 and the three-leaf specimen 5; a plurality of loading angle holes 2a are evenly distributed on the outer peripheral edges of the porous loading disk one 2 and the porous loading disk two 21.

[0060] In the present invention, as a preference, the number of the loading angle holes 2a is 13. The angles between each loading angle hole 2a and the vertical direction are successively: 0°, 7.5°, 15°, 22.5°, 30°, 37.5°, 45°, 52.5°, 60°, 67.5°, 75°, 82.5°, 90°. The structures and sizes of the loading angle holes 2a and the loading arm pin holes 1b are the same, and a regular hexagon-shaped first nut mounting groove 2b is concentrically arranged around each loading angle hole 2a for cooperating with the installation of the pin connection system 7.

[0061] On the porous loading disk 2, two first specimen mounting arm holes 2c are arranged side by side in the same vertical direction as the first loading angle hole 2a. Their sizes and structures are the same as those of the loading angle hole 2a, and second nut mounting grooves are provided around them for cooperating with the specimen mounting mechanism 4 for installation.

[0062] The porous loading disk 21 is a derivative form of the porous loading disk 2. It does not have the first nut mounting groove 2b and the second nut mounting groove, and is used to sandwich the loading arm 1 and the specimen mounting mechanism 4 between the porous loading disk 2, and cooperate with the disk fastening system 3 for fastening installation.

[0063] Each set of disk fastening systems includes: a disk bolt 31, a disk nut 32, and a disk fastening gasket 33. The screw part of the disk bolt 31 is semi-threaded. The disk nut 32 has a regular hexagonal structure, and its size is the same as that of the second nut mounting groove. The inner diameter of the disk fastening gasket 33 is slightly larger than the screw diameter of the disk bolt 31.

[0064] As Figure 3 shown, the three-leaf specimen 5 is in the shape of a "maple leaf". The three round holes are distributed at every 120° around the structural center. First specimen mounting holes 5a are concentrically provided at the three round hole positions respectively for cooperating with the specimen mounting mechanism 4 for installation. Two three-leaf specimens 5 are stacked with a 60° center offset and are connected into an integral specimen through the connection form required for the test.

[0065] The thickness adjustment gasket 8 has the same structure as the three-leaf specimen 5, and thickness adjustment gasket mounting holes 8a identical to the specimen mounting holes are provided at its three ports. A hollow circular space is provided at the structural center of the thickness adjustment gasket 8 to form a gasket hole 8b, whose size is the same as that of the specimen connection groove 4c, for ensuring the normal installation of the specimen connection form with longitudinal space requirements. The thickness of the thickness adjustment gasket 8 is not specifically required. Its main purpose is to ensure that the thicknesses of the two three-leaf specimens 5 are the same, thereby avoiding the generation of unnecessary torques.

[0066] The specimen mounting mechanism includes: a specimen mounting arm 41 and a specimen mounting table 42. The specimen mounting arm 41 has a rectangular body structure, with one end connected to the bottom of the specimen mounting table 42 and the other end provided with two second specimen mounting arm holes 4d arranged side by side. The second specimen mounting arm holes 4d have the same size as the first specimen mounting arm holes 2c. The specimen mounting table 42 has the same structure as the three-leaf specimen 5, both being in the shape of a "maple leaf". A second specimen mounting hole 4b is provided on one side of each round hole, and a third nut mounting groove 4a is provided on the other side. The second specimen mounting holes 4b have the same position and size as the first specimen mounting holes, and the third nut mounting groove 4a has the same structure and size as the first and second nut mounting grooves.

[0067] The specimen fastening system 6 includes: a specimen bolt 61, a specimen nut 62, and a specimen fastening gasket 63; the screw part of the specimen bolt 61 is semi-threaded, one end of the specimen nut 62 is regular hexagon-shaped, and its size is the same as that of the third nut installation groove 4a. The inner diameter of the specimen fastening gasket 63 is slightly larger than the screw diameter of the specimen bolt 61.

[0068] The pin connection system 7 includes: a loading arm connection pin 71 and a connection circlip 72. One end of the loading arm connection pin 71 is regular hexagon-shaped, and its size is the same as that of the first nut installation groove 2b and can be embedded therein. The other end of the loading arm connection pin 71 is provided with an annular groove 7a. The connection pin circlip 72 is of a C-shaped structure and has a notch, and its size is consistent with that of the annular groove 7a. The connection pin circlip 72 is arranged in a matching manner with the annular groove 7a.

[0069] The specific installation process includes:

[0070] After stacking two three-leaf specimens 5 with a 60° central deflection, an integral specimen is formed according to the connection form required for the test.

[0071] In the present invention, as a preference, the connection form is point connection, which is at least one of spot welding, riveting, spot gluing, and bolt connection.

[0072] In another embodiment, the connection form can be: multi-point connection or surface connection.

[0073] A loading arm connection pin 71 is sequentially passed through the loading angle holes 2a on the porous loading disk one 2, the loading arm pin hole 1b, and the corresponding loading angle holes on the porous loading disk two 21; the regular hexagon end of the loading arm connection pin 71 is placed in the first nut installation groove 2b to prevent axial rotation; the connection pin circlip 72 is snapped into the annular groove 7a to play a limiting role on the loading arm connection pin 71, and the clamping installation of the loading arm 1 and the porous loading disk 2 is completed.

[0074] Two disk nuts 32 are respectively placed in the two second nut installation grooves. After two disk bolts 31 are coaxially installed with two disk fastening gaskets 33 respectively, the disk bolts 32 are sequentially passed through the first specimen installation arm holes 2c on the porous loading disk two 21, the second specimen installation arm holes 4d, and the first specimen installation arm holes 2c on the porous loading disk one 2; an inner hexagon wrench is used to screw the disk bolts 31 into the disk nuts 32, and the clamping installation of the specimen installation arm 41 and the porous loading disk 2 is completed.

[0075] Place the three specimen nuts 62 in the three third nut mounting grooves 4a respectively. After coaxially assembling the specimen bolt 61 and the specimen fastening gasket 62, pass them through the first specimen mounting hole 5a, the thickness adjustment gasket mounting hole 8a (which can be ignored if not needed), and the second specimen mounting hole 4b in sequence, and use an Allen wrench to screw the specimen bolt 61 into the specimen nut 62, thereby realizing the installation of one side of the three-lobe specimen. The other side is the same. During the installation process, an L-shaped Allen wrench can be used to tighten the outer specimen bolt 61 through the rectangular notch on the multi-hole loading disc, and a long-bar Allen wrench can be used to tighten the gap between the multi-hole loading disc one 2 and the multi-hole loading disc two 21 for the inner specimen bolt. Example 1

[0076] Assemble the loading arm 1 and the different loading angle holes 2a, including:

[0077] As Figure 4 shown, the loading angle holes 2a include: the first group of holes and the second group of holes. Among them, the first group of holes includes: hole one 201, hole two 202, hole three 203, hole four 204, hole five 205, hole six 206, hole seven 207, hole eight 208, hole nine 209, hole ten 210, hole eleven 211, hole twelve 212, hole thirteen 213, and the second group of holes includes: hole fourteen 214, hole fifteen 215, hole sixteen 216, hole seventeen 217, hole eighteen 218, hole nineteen 219, hole twenty 220, hole twenty-one 221, hole twenty-two 222, hole twenty-three 223, hole twenty-four 224, hole twenty-five 225, hole twenty-six 226. According to the combination of different holes, the direction of the external force loading is made to be at different angles (0°, 7.5°, 15°, 22.5°, 30°, 37.5°, 45°, 52.5°, 60°, 67.5°, 75°, 82.5°, 90°) with the uniaxial tension direction, thereby realizing different tension-shear ratio loadings. The specific hole combinations corresponding to each angle are shown in Table 1.

[0078] Table 1 Explanation table of the loading angle hole combination and the tension-shear ratio of the present invention

[0079]

[0080] The combination of hole 1 and hole 2 can realize the transition of the stress state from pure normal stress to pure shear stress. As Figure 4 shown, taking the loading center as the origin O , decompose the combined stress into the normal stress σ and the shear stress τ appropriately according to the loading angle.

[0081] The σ of the normal stress and the shear stress τ can be respectively expressed as:

[0082]

[0083]

[0084] Among them, σ is the normal stress; τ is the shear stress; F is the failure load; S is the connection area; θ is the loading angle.

[0085] Tensile-shear ratio η can be defined as the ratio of the normal stress σ to the shear stress τ :

[0086]

[0087] The tensile-shear ratios at specific loading angles are shown in Table 1.

[0088] In the present invention, the specific number of the loading angle holes 2a is not required, and the number can be determined by itself according to the actual requirements and the size of each component on the premise of not affecting the normal functions of each component. Embodiment 2

[0089] The center of the specimen is connected by using different connection forms, including:

[0090] As shown in Fig. 5, the sectional views of the three-leaf specimens 5 with three different point connection forms are shown; as shown in Fig. 5(a), the centers of two three-leaf specimens 5 are connected by spot welds 51; as shown in Fig. 5(b), rivet installation holes are provided at the centers of the three-leaf specimens 5, and the centers of two three-leaf specimens 5 are connected by rivet joints 52; as shown in Fig. 5(c), two three-leaf specimens 5 are connected by adhesive joints 53.

[0091] The present invention can also be compatible with various connection forms such as multi-point connection and surface connection.

[0092] It can be seen from the above embodiments that the biaxial tensile-shear loading test fixture provided by the present invention, which can be compatible with various connection forms, can freely control the tensile-shear ratio of the applied load according to the actual requirements, and can effectively be compatible with point connection forms such as spot welding, riveting, and spot gluing, and test the biaxial tensile-shear characteristics of the connection form, and has the characteristics of good compatibility, excellent operability, and high reliability.

[0093] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and embodiments. It can be fully applied to various fields suitable for the present invention. For those skilled in the art, additional modifications can be easily made. Therefore, without departing from the general concept defined by the claims and the equivalent scope, the present invention is not limited to the specific details and the examples shown and described herein.

Claims

1. A biaxial tensile-shear loading test fixture compatible with multiple connection forms, characterized in that, Comprising: Two pairs of upper and lower porous loading disks, which are oppositely arranged. In each pair of porous loading disks, the two porous loading disks are spaced apart. The porous loading disks are quarter-circular structures and have rectangular notches at the centers; A plurality of loading angle holes, which are spaced along the circumferences of the porous loading disks; Two loading arms, one end of which is arranged between the two spaced porous loading disks; Two sets of pin connection systems, one end of which passes through the loading angle holes and the loading arms to detachably connect the loading arms to the porous loading disks; Two specimen mounting mechanisms, which are oppositely arranged, and one end of the specimen mounting mechanism is arranged between the two spaced porous loading disks; A plurality of disk fastening systems, one end of which passes through the porous loading disks and one end of the specimen mounting mechanism to detachably connect the specimen mounting mechanism to the porous loading disks; A specimen mechanism, which includes two three-leaf specimens. After the two specimens rotate 60° relative to each other with the structural center as the origin, they are point-connected at the center; the two specimens are respectively arranged at the other ends of the two specimen mounting mechanisms; The three circular openings of the three-leaf specimen are distributed at every 120° with the structural center, and first specimen mounting holes are concentrically opened at the three circular openings respectively; A thickness adjustment gasket, which has the same structure as the three-leaf specimen, and thickness adjustment gasket mounting holes identical to the first specimen mounting holes are provided at its three ports; A plurality of specimen fastening systems, one end of which passes through the other end of the specimen mounting mechanism and the specimen to detachably connect the specimen to the specimen mounting mechanism.

2. The biaxial tensile-shear loading test fixture compatible with multiple connection forms according to claim 1, characterized in that, It further includes: A plurality of first nut mounting grooves, which are regular hexagon structures, are concentrically arranged with the plurality of loading angle holes, and are located on one of the porous loading disks in each pair of porous loading disks; A loading arm pin hole, which is arranged at one end of the loading arm; A loading arm connecting pin, one end of which is a regular hexagon and is arranged to match the first nut mounting groove; an annular groove is arranged along the circumference at the other end of the loading arm connecting pin; A connecting pin circlip, which is a C-shaped structure and is arranged to match the annular groove; Wherein, the loading arm pin hole is arranged to match the loading angle hole, and the other end of the loading arm connecting pin passes through the loading angle hole and the loading arm pin hole and is positioned by the connecting pin circlip arranged in the annular groove; A loading arm mounting hole, which is opened on the side of the other end of the loading arm.

3. The biaxial tensile-shear loading test fixture capable of being compatible with multiple connection forms according to claim 2, wherein The fixing method between the two specimens is at least one of welding, riveting, bolt connection, and bonding.

4. The biaxial tension-shear loading test fixture compatible with multiple connection forms according to claim 3, characterized in that, It further includes: First specimen mounting arm holes, which are opened on the porous loading disks and are close to the rectangular notches; Wherein, on each of the porous loading disks, the number of the first specimen mounting arm holes is at least two.

5. The biaxial tensile-shear loading test fixture compatible with multiple connection forms according to claim 4, characterized in that, The specimen mounting mechanism includes: A specimen mounting arm, which is a rectangular body structure, and at least two second specimen mounting arm holes are opened at one end thereof; A specimen mounting table, which is fixedly arranged at the other end of the specimen mounting arm; The specimen mounting table has the same shape as the specimen, and a specimen connection groove is opened in the middle of the specimen mounting table, and second specimen mounting holes are respectively opened at the circular ends of the specimen mounting table.

6. The biaxial tension-shear loading test fixture compatible with multiple connection forms according to claim 5, characterized in that, A second nut installation groove is concentrically provided in the first specimen installation arm hole, which has the same structure as the first nut installation groove and is located on the same porous loading plate.

7. The biaxial tensile-shear loading test fixture compatible with multiple connection forms according to claim 6, characterized in that, The disk fastening system includes: a disk bolt, a disk nut, and a disk fastening gasket; One end of the disk bolt passes through the first specimen installation arm hole and the second specimen installation arm hole and is fixed by the disk nut. The disk fastening gasket is located between the disk bolt and the porous loading plate, and the disk nut is arranged in the second nut installation groove.

8. The biaxial tension-shear loading test fixture compatible with multiple connection forms according to claim 7, characterized in that, The specimen fastening system includes a specimen bolt, a specimen nut, and a specimen fastening gasket that are matched; One end of the specimen bolt sequentially passes through the first specimen installation hole and the second specimen installation hole and is fixed by the specimen nut; The specimen fastening gasket is arranged between the specimen bolt and the specimen installation table.

9. The biaxial tensile-shear loading test fixture compatible with multiple connection forms according to claim 8, characterized in that, The number of the loading angle holes is 13, and the included angles between the loading angle holes and the vertical direction are successively: 0°, 7.5°, 15°, 22.5°, 30°, 37.5°, 45°, 52.5°, 60°, 67.5°, 75°, 82.5°, 90°.

Images