A fixed clamping device for testing the shear performance of carbon fiber composite materials

Abstract

The present application relates to the technical field of composite material performance testing equipment, and particularly relates to a fixing and clamping device for testing shear performance of carbon fiber composite material, a first tensile chuck is arranged on an upper clamp, one end of a first guide column is connected with the upper clamp, the other end of the first guide column is slidably connected with a lower clamp, a second tensile chuck is arranged on the lower clamp, one end of a second guide column is connected with the lower clamp, and the other end is slidably connected with the upper clamp, a correction mechanism is arranged in the upper clamp and the lower clamp, and is used for correcting a sample; a clamping mechanism is arranged in the upper clamp and the lower clamp, and is used for clamping the sample. The correction mechanism arranged in the upper clamp and the lower clamp can quickly correct the position of the sample, ensure that the vertical center line of the sample coincides with the loading center line, effectively avoid the test error caused by eccentric loading, and improve the convenience and accuracy of centering operation.

Description

Technical Field

[0001] This invention relates to the field of composite material performance testing equipment, and in particular to a fixing and clamping device for testing the shear properties of carbon fiber composite materials. Background Technology

[0002] Carbon fiber composites are widely used in the manufacture of critical structural components due to their excellent properties such as high strength, lightweight, and corrosion resistance. Shear performance, as one of the core mechanical properties of carbon fiber composites, directly affects the load-bearing safety and service life of structural components; therefore, accurate testing of its shear performance is crucial.

[0003] Currently, the V-grooved specimen shear test is the mainstream method for this performance test due to its ease of operation and clear failure characteristics. However, existing clamping devices used for this test have significant defects and cannot meet the requirements of accurate testing. For example, there is a lack of a dedicated calibration mechanism, the centering and positioning operation during specimen installation is cumbersome and prone to eccentricity, making it impossible to ensure that the vertical centerline of the specimen coincides with the loading centerline, which directly affects the accuracy of the test results. The stability of the connecting guide structure of the upper and lower clamps is poor, and relative offset is prone to occur during loading, causing the specimen to bear additional frictional force. Summary of the Invention

[0004] The present invention provides a fixing and clamping device for testing the shear properties of carbon fiber composite materials, which solves at least one of the above-mentioned technical problems.

[0005] A fixing and clamping device for testing the shear properties of carbon fiber composites, comprising: Upper clamp; The first tension chuck is mounted on the upper clamp; The first guide post has one end connected to the upper clamp; The other end of the first guide post is slidably connected to the lower clamp; The second tension chuck is mounted on the lower clamp. The second guide post has one end connected to the lower clamp and the other end slidably connected to the upper clamp; The upper and lower clamps are equipped with a calibration mechanism for calibrating the sample. The clamping mechanism is provided inside both the upper and lower clamps to hold the sample.

[0006] In one embodiment, both the first guide post and the second guide post include: The first fixed shaft has one end connected to the upper or lower clamp; A spherical positioning head is located at the other end of the first fixed shaft; The second fixed shaft is slidably connected inside the upper or lower clamp; A spherical bushing is located at the end of the second fixed shaft and is hinged to the spherical positioning head.

[0007] In one embodiment, the calibration mechanism includes: The first movable plate is slidably connected inside the upper clamp; A first fixed plate is disposed on a first movable plate; The second movable plate is slidably connected to the first movable plate; The third fixed shaft is fixed to the first fixed plate and slidably connected to the second movable plate; The first roller is rotatably connected to the second movable plate and is used to abut the sample. The second fixing plate is located inside the upper clamp; The first spring has one end connected to the first movable plate and the other end connected to the second fixed plate.

[0008] In one embodiment, the calibration mechanism further includes: The third movable plate is slidably connected inside the lower clamp; The second roller is rotatably connected to the third moving plate and is used to abut the sample. The third fixing plate is located inside the lower clamp; The second spring has one end connected to the third movable plate and the other end connected to the third fixed plate.

[0009] In one embodiment, multiple sets of the third moving plate, the second roller, the third fixed plate, and the second spring are provided, and the included angle between two adjacent sets of the third moving plates is adapted to the angle of the sample contact portion.

[0010] In one embodiment, both the upper and lower clamps are provided with arc-shaped portions, and stress relief grooves are provided on the arc-shaped portions. Cross-shaped ribs are provided inside the stress relief grooves.

[0011] In one embodiment, the clamping mechanism includes: The fourth movable plate is slidably connected inside the upper and lower clamps; A clamping block is mounted on the fourth movable plate; The slider is slidably connected inside the upper and lower clamps; The hinge rod has one end hinged to the clamping block and the other end hinged to the slider; The fourth fixed plate is mounted on the fourth movable plate; The fifth fixing plate is located inside the upper and lower clamps; The fourth fixed shaft has one end connected to the fourth fixed plate and the other end passing through the fifth fixed plate and slidably connected to the fifth fixed plate. The third spring has one end abutting against the fourth fixed plate and the other end abutting against the fifth fixed plate.

[0012] In one embodiment, both the upper and lower clamps are provided with at least two sets of clamping mechanisms, and the edges of the clamping blocks are arc-shaped.

[0013] In one embodiment, both the upper and lower clamps are L-shaped, and the sample is clamped between the upper and lower clamps. The bottom end face of the sample abuts against the upper clamp, and the top end face abuts against the lower clamp.

[0014] In one embodiment, both the first tension chuck and the second tension chuck are provided with universal joints.

[0015] Compared with existing technologies, the advantages of this invention are as follows: By setting a correction mechanism inside the upper and lower clamps, the sample position can be quickly corrected, ensuring that the vertical centerline of the sample coincides with the loading centerline, effectively avoiding test errors caused by eccentric loading, and improving the convenience and accuracy of centering operations. The clamping mechanism and the correction mechanism work together to simplify the sample installation and removal process, eliminating the need for complex adjustments and significantly improving testing efficiency. The sliding connection structure of the first guide post and the second guide post, combined with the symmetrical layout of the upper and lower clamps, enhances the overall structural stability of the clamps and reduces relative offset and additional friction during loading. The clamp structure has strong resistance to bending deformation, effectively preventing the sample from simultaneously bearing shear and bending loads under large loads, ensuring that the sample forms a pure shear mechanical state. Attached Figure Description

[0016] The invention will now be described in more detail with reference to embodiments and the accompanying drawings.

[0017] Figure 1 This is a schematic diagram of the structure of a fixing and clamping device for testing the shear properties of carbon fiber composite materials according to the present invention.

[0018] Figure 2 This is a cross-sectional structural schematic diagram of a fixing and clamping device for testing the shear properties of carbon fiber composite materials according to the present invention.

[0019] Figure 3 This is a schematic diagram of the correction mechanism in a fixed clamping device for testing the shear properties of carbon fiber composite materials according to the present invention.

[0020] Figure 4 This is a schematic diagram of the arc-shaped part in a fixing and clamping device for testing the shear properties of carbon fiber composite materials according to the present invention.

[0021] Figure 5 This is a schematic diagram of the clamping mechanism in a fixed clamping device for testing the shear properties of carbon fiber composite materials according to the present invention.

[0022] Reference numerals: 1. Upper clamp; 2. First tension chuck; 3. First guide post; 31. First fixed shaft; 32. Spherical positioning head; 33. Second fixed shaft; 34. Spherical bushing; 4. Lower clamp; 5. Second tension chuck; 6. Second guide post; 7. Correction mechanism; 701. First moving plate; 702. First fixed plate; 703. Second moving plate; 704. Third fixed shaft; 705. First roller; 706. Second fixed plate; 70 7. First spring; 708. Third moving plate; 709. Second roller; 710. Third fixed plate; 711. Second spring; 8. Arc-shaped part; 81. Stress relief groove; 82. Cross rib plate; 9. Clamping mechanism; 901. Fourth moving plate; 902. Clamping block; 903. Slider; 904. Hinge rod; 905. Fourth fixed plate; 906. Fifth fixed plate; 907. Fourth fixed shaft; 908. Third spring; 10. Universal joint. Detailed Implementation

[0023] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Although the invention has been described with reference to preferred embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the invention. In particular, the technical features mentioned in the various embodiments can be combined in any manner as long as there is no structural conflict. The invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

[0025] As described in the background section, the V-groove specimen shear test has become the mainstream method for this performance test due to its ease of operation and clear destructive characteristics. However, existing clamping devices used for this test have significant defects and cannot meet the requirements for accurate testing. For example, they lack a dedicated calibration mechanism, the centering and positioning operation during specimen installation is cumbersome and prone to eccentricity, making it impossible to ensure that the vertical centerline of the specimen coincides with the loading centerline, which directly affects the accuracy of the test results. Furthermore, the stability of the connecting guide structure of the upper and lower clamps is poor, and relative offset is prone to occur during loading, causing the specimen to bear additional frictional force.

[0026] To solve the above problems, refer to Figure 1This invention provides a fixing and clamping device for testing the shear properties of carbon fiber composite materials, comprising: an upper clamp 1, a first tensile clamp 2, a first guide post 3, a lower clamp 4, a second tensile clamp 5, a second guide post 6, a correction mechanism 7, and a clamping mechanism 9. The first tensile clamp 2 is disposed on the upper clamp 1. One end of the first guide post 3 is connected to the upper clamp 1, and the other end of the first guide post 3 is slidably connected to the lower clamp 4. The second tensile clamp 5 is disposed on the lower clamp 4. One end of the second guide post 6 is connected to the lower clamp 4, and the other end is slidably connected to the upper clamp 1. The correction mechanism 7 is provided inside the upper clamp 1 and the lower clamp 4 for correcting the sample. The clamping mechanism 9 is provided inside the upper clamp 1 and the lower clamp 4 for clamping the sample.

[0027] Specifically, the upper clamp 1 and the lower clamp 4 are arranged opposite each other to form a symmetrical clamping structure. The first tensile clamp 2 is fixed to the upper clamp 1, and the second tensile clamp 5 is fixed to the lower clamp 4. The two serve as the interface for transmitting the loading force of the testing machine, ensuring that the tensile force is stably transmitted along the axial direction. One end of the first guide post 3 is connected to the upper clamp 1, and the other end is slidably connected to the lower clamp 4; one end of the second guide post 6 is connected to the lower clamp 4, and the other end is slidably connected to the upper clamp 1, forming a bidirectional guiding constraint, limiting the lateral offset and torsion of the upper clamp 1 and the lower clamp 4, and ensuring that their movements are synchronous and concentric. Both the upper clamp 1 and the lower clamp 4 are equipped with a correction mechanism 7 and a clamping mechanism 9. The correction mechanism 7 is used to adjust the position of the specimen to ensure that the vertical centerline of the specimen coincides with the loading centerline; the clamping mechanism 9 is used to firmly clamp the specimen after correction, preventing loosening and displacement during loading, ensuring that the force is transmitted along the central axis of the specimen, and providing a structural basis for pure shear testing.

[0028] Furthermore, the overall structure of this invention can effectively avoid offset and additional load during loading. The symmetrical layout and combination of bidirectional guide columns improve the overall stability of the device and increase the testing accuracy. The built-in correction mechanism 7 and clamping mechanism 9 optimize the external structure and reduce the difficulty of operation. At the same time, they reserve adjustment space to adapt to samples of different specifications, making it more versatile.

[0029] Furthermore, the present invention can also make the upper clamp 1 and the lower clamp 4 out of high-strength lightweight alloy material, thereby reducing the weight of the device and reducing the inertial impact during the loading process while ensuring structural rigidity. In addition, the first tension clamp 2 and the second tension clamp 5 can be replaced with a modular structure that can be quickly replaced and equipped with various interface adapters to adapt to the loading interfaces of different models of testing machines.

[0030] Preferred, such as Figure 1As shown, both the first guide post 3 and the second guide post 6 include: a first fixed shaft 31, a spherical positioning head 32, a second fixed shaft 33, and a spherical bushing 34. One end of the first fixed shaft 31 is connected to the upper clamp 1 or the lower clamp 4. The spherical positioning head 32 is disposed at the other end of the first fixed shaft 31. The second fixed shaft 33 is slidably connected to the inside of the upper clamp 1 or the lower clamp 4. The spherical bushing 34 is disposed at the end of the second fixed shaft 33 and is hinged to the spherical positioning head 32.

[0031] Specifically, the first guide post 3 and the second guide post 6 adopt the same split structure, both consisting of a first fixed shaft 31, a spherical positioning head 32, a second fixed shaft 33, and a spherical bushing 34. One end of the first fixed shaft 31 is rigidly connected to the upper clamp 1 or the lower clamp 4 to ensure the reliability of the connection between the guide post and the clamp body. The spherical positioning head 32 is located at the other end of the first fixed shaft 31 and forms a hinged fit with the spherical bushing 34 at the end of the second fixed shaft 33. The second fixed shaft 33 is slidably connected inside the corresponding upper clamp 1 or lower clamp 4, providing a guide stroke for the relative movement of the clamps. The hinged structure of the spherical positioning head 32 and the spherical bushing 34 allows for a certain angle of deflection, which can adaptively compensate for minor coaxiality errors during installation and minor deformation of the clamps during loading, avoiding jamming or additional torque caused by errors in traditional rigid guide posts, and achieving flexible guidance.

[0032] Furthermore, the spherical hinge structure has error compensation capabilities, effectively improving guiding accuracy and loading stability. The point contact fit reduces friction during relative movement, ensuring smooth axial movement of the fixture. The hinged parts can have their wear resistance improved through surface treatment, while also absorbing impact loads during loading, protecting the fixture and the sample.

[0033] Furthermore, a lubrication groove can be opened inside the spherical bushing 34 to inject solid grease or to make the bushing with self-lubricating materials to further reduce motion resistance. Guide columns with different stiffness levels can also be designed by changing the diameter and material strength of the first fixed shaft 31 and the second fixed shaft 33 to adapt to low-load high-precision and high-load stability testing scenarios.

[0034] Preferred, such as Figure 2 , 3As shown, the calibration mechanism 7 includes: a first movable plate 701, a first fixed plate 702, a second movable plate 703, a third fixed shaft 704, a first roller 705, a second fixed plate 706, and a first spring 707. The first movable plate 701 is slidably connected to the inside of the upper clamp 1. The first fixed plate 702 is disposed on the first movable plate 701. The second movable plate 703 is slidably connected to the first movable plate 701. The third fixed shaft 704 is fixed on the first fixed plate 702 and slidably connected to the second movable plate 703. The first roller 705 is rotatably connected to the second movable plate 703 for abutting the sample. The second fixed plate 706 is disposed inside the upper clamp 1. One end of the first spring 707 is connected to the first movable plate 701, and the other end is connected to the second fixed plate 706.

[0035] Specifically, the first movable plate 701 is slidably connected inside the upper clamp 1 and its position can be adjusted horizontally; the first fixed plate 702 is fixed to the first movable plate 701, the third fixed shaft 704 is vertically fixed to the first fixed plate 702, and the second movable plate 703 is slidably connected to the third fixed shaft 704, forming a vertical adjustment degree of freedom. The first roller 705 is rotatably connected to the second movable plate 703 and makes flexible contact with the sample surface. One end of the first spring 707 is connected to the first movable plate 701, and the other end is connected to the second fixed plate 706 inside the upper clamp 1. In its natural state, it is in a pre-tightened state, providing continuous elastic pressure to the first movable plate 701. After the sample is placed, the first roller 705 conforms to the sample contour under the spring pressure. Through the linkage of the multi-dimensional movable plates, the sample is pushed to the center position, achieving centering correction.

[0036] Furthermore, the rolling contact between the first roller 705 and the sample reduces friction and prevents scratches on the sample surface; the elastic pre-tightening structure can adapt to samples of different sizes, the centering accuracy is not affected by manual operation, the calibration process is completed automatically, and there is no need for repeated manual adjustments, which greatly improves the testing efficiency. The calibration force is within a controllable range, avoiding damage to brittle samples due to excessive pressure.

[0037] Furthermore, the single first spring 707 can be replaced with a multi-spring array to achieve graded adjustment of the correction force, adapting to both thin-walled and thick-walled samples; the first roller 705 is wrapped with a metal mandrel using polyurethane or rubber material to enhance fit and cushioning effect; limit blocks are added to the first moving plate 701 and the second moving plate 703 to limit the adjustment stroke and prevent excessive compression of the sample.

[0038] Preferred, such as Figure 2As shown, the calibration mechanism 7 also includes: a third moving plate 708, a second roller 709, a third fixed plate 710, and a second spring 711. The third moving plate 708 is slidably connected inside the lower clamp 4, the second roller 709 is rotatably connected to the third moving plate 708 and is used to abut the sample, the third fixed plate 710 is disposed inside the lower clamp 4, one end of the second spring 711 is connected to the third moving plate 708, and the other end is connected to the third fixed plate 710.

[0039] Specifically, the third moving plate 708 is slidably connected inside the lower clamp 4, the second roller 709 is rotatably connected to the third moving plate 708, the third fixed plate 710 is fixed inside the lower clamp 4, and one end of the second spring 711 is connected to the third moving plate 708, and the other end is connected to the third fixed plate 710. It is structurally symmetrical and has a matching elastic coefficient with the first spring 707 inside the upper clamp 1. After the sample is placed in, the first roller 705 of the upper clamp 1 and the second roller 709 of the lower clamp 4 contact the sample from the top and bottom directions respectively. The bidirectional springs provide equal and opposite elastic pressures, pushing the sample from both directions to adjust its position, eliminating the blind spot of single-direction correction, and ensuring precise vertical alignment of the sample.

[0040] Furthermore, the upper and lower coordinated correction structure improves the centering accuracy and avoids bending loads caused by sample tilting. The bidirectional elastic pre-tightening makes the sample surface more uniformly stressed, reduces local pressure concentration, and protects brittle samples. At the same time, the clamping mechanism 9 is adapted to the symmetrical layout of the fixture body, which improves the overall mechanical balance of the device and reduces loading vibration.

[0041] Furthermore, the first spring 707 and the second spring 711 can be connected by a linkage mechanism to achieve synchronous adjustment of the elastic force of the upper and lower springs, ensuring that the sample is subjected to balanced force. Multiple sets of second rollers 709 are added to the third moving plate 708 and evenly distributed along the length of the sample to enhance the correction effect of long-sized samples.

[0042] Preferred, such as Figure 2 As shown, multiple sets of the third moving plate 708, the second roller 709, the third fixed plate 710, and the second spring 711 are provided, and the included angle between two adjacent sets of the third moving plate 708 is adapted to the angle of the sample contact part.

[0043] Specifically, the third moving plate 708, the second roller 709, the third fixed plate 710, and the second spring 711 are configured in multiple groups, evenly distributed along the circumference of the sample, with each group of components independently providing elastic correction force. The included angle between two adjacent groups of the third moving plate 708 is precisely designed according to the angle of the sample contact portion, ensuring that the second roller 709 can completely conform to the surface contour of the sample. The multiple groups of components adaptively adjust their positions through the elastic force of the independent springs, ensuring that each contact point is uniformly stressed evenly, pushing the sample to the center position from multiple directions and preventing sample displacement, even if there are slight protrusions on the sample surface.

[0044] Furthermore, the clamping mechanism 9 fits into irregularly shaped specimens such as V-shaped notches, solving the problem of poor adaptability of traditional correction structures to irregularly shaped specimens and ensuring no displacement or torsion during loading; the multi-contact design disperses the clamping pressure, further protecting brittle specimens; the coordinated work of multiple components reduces the impact of wear on a single component on the correction effect, improving structural stability and repeatability.

[0045] Furthermore, each set of calibration components can be designed as an independent modular unit, connected to the lower clamp 4 through a standardized interface, and the number of units can be flexibly increased or decreased or the angle adjusted according to the shape of the sample; the third moving plate 708 can also be designed as a rotatable and adjustable form to achieve stepless adjustment of the included angle and adapt to samples with different angle notches; a micro displacement sensor can also be added to each set of second rollers 709 to monitor the degree of fit in real time.

[0046] Preferred, such as Figure 1 , 4 As shown, both the upper clamp 1 and the lower clamp 4 are provided with arc-shaped parts 8, and stress relief grooves 81 are provided on the arc-shaped parts 8. Cross-shaped stiffeners 82 are provided inside the stress relief grooves 81.

[0047] Specifically, the arc-shaped portions 8 on the upper clamp 1 and the lower clamp 4 are the main stress-bearing areas, which are prone to stress concentration during loading. The stress relief groove 81 is opened along the stress direction of the arc-shaped portion 8, which can effectively disperse the concentrated stress and avoid excessive stress accumulation in a local area, which would cause the clamp to bend and deform. The cross-shaped stiffening plate 82 is fixed inside the stress relief groove 81 to form a mesh support structure, which greatly improves the structural rigidity and bending strength of the arc-shaped portion 8 without affecting the stress dispersion function.

[0048] Furthermore, the cross-shaped stiffener 82 and the stress relief groove 81 significantly improve the clamp's resistance to bending and deformation, preventing clamp deformation under heavy loads; the stress dispersion effect is also better.

[0049] Preferred, such as Figure 5As shown, the clamping mechanism 9 includes: a fourth moving plate 901, a clamping block 902, a slider 903, a hinge rod 904, a fourth fixed plate 905, a fifth fixed plate 906, a fourth fixed shaft 907, and a third spring 908. The fourth moving plate 901 is slidably connected to the interior of the upper clamp 1 and the lower clamp 4. The clamping block 902 is disposed on the fourth moving plate 901. The slider 903 is slidably connected to the interior of the upper clamp 1 and the lower clamp 4. One end of the hinge rod 904 is hinged to the clamping block 902, and the other end is hinged to the slider 903. The fourth fixed plate 905 is disposed on the fourth moving plate 901. The fifth fixed plate 906 is disposed inside the upper clamp 1 and the lower clamp 4. One end of the fourth fixed shaft 907 is connected to the fourth fixed plate 905, and the other end passes through the fifth fixed plate 906 and is slidably connected to the fifth fixed plate 906. One end of the third spring 908 abuts against the fourth fixed plate 905, and the other end abuts against the fifth fixed plate 906.

[0050] Specifically, the fourth moving plate 901 is slidably connected inside the upper clamp 1 and the lower clamp 4, and the clamping block 902 is fixed on the fourth moving plate 901, directly contacting the sample. The slider 903 is slidably connected in the internal groove of the clamp, and the two ends of the hinge rod 904 are hinged to the clamping block 902 and the slider 903 respectively, forming a four-bar linkage structure. The fourth fixed plate 905 is fixed on the fourth moving plate 901, and the fifth fixed plate 906 is fixed inside the clamp. One end of the fourth fixed shaft 907 is connected to the fourth fixed plate 905, and the other end passes through the fifth fixed plate 906 and forms a sliding fit. The third spring 908 is sleeved on the fourth fixed shaft 907 and is in a pre-compressed state. After the sample is calibrated, by driving the slider 903 or using the spring force, the hinge rod 904 drives the clamping block 902 to move towards the sample. The third spring 908 provides a continuous elastic clamping force to achieve stable clamping.

[0051] Furthermore, the spring preload provides a constant clamping force, preventing excessive clamping force from damaging the sample or insufficient clamping force from causing the sample to loosen. In this invention, the slider can be driven manually or automatically to achieve clamping and releasing actions. The structure has high reliability, and worn parts can be maintained by replacing vulnerable parts, thus extending the service life.

[0052] Furthermore, an adjusting nut can be added to the fourth fixed shaft 907 to change the pre-compression of the third spring 908, thereby achieving stepless adjustment of the clamping force; the clamping block 902 can be replaced with a replaceable modular structure, equipped with clamping blocks of different materials and shapes to adapt to different sample requirements; an anti-slip coating or soft pad can also be added to the surface of the clamping block 902 to enhance friction and protect the sample surface.

[0053] Preferred, such as Figure 5 As shown, both the upper clamp 1 and the lower clamp 4 are equipped with at least two sets of clamping mechanisms 9 inside, and the edge of the clamping block 902 is arc-shaped.

[0054] Specifically, both the upper clamp 1 and the lower clamp 4 are equipped with no fewer than two sets of clamping mechanisms 9, which are evenly distributed along the length of the sample to form multi-point clamping constraints, disperse clamping pressure, and limit axial movement and lateral displacement of the sample. The edge of the clamping block 902 is designed to be arc-shaped to avoid scratches or crush damage to the sample caused by right-angled edges.

[0055] Furthermore, the multi-point clamping constraint of the multiple clamping mechanisms 9 significantly improves clamping stability and prevents the sample from loosening under heavy loads or vibrations; the arc-shaped edge clamping block effectively protects the sample surface and reduces damage caused by local stress concentration; and it has stronger adaptability.

[0056] Furthermore, replaceable arc-shaped pads can be set on the arc-shaped edge of the clamping block 902, equipped with different rounded corner radii to adapt to samples of different thicknesses and materials; or a transverse clamping mechanism can be added to form a bidirectional clamping constraint in both axial and transverse directions, further limiting the torsion and transverse displacement of the sample; a pressure sensor can be added to the clamping block 902 of each clamping mechanism 9 to monitor the clamping force distribution in real time and ensure uniform force distribution.

[0057] Preferred, such as Figure 1 , 2 As shown, both the upper clamp 1 and the lower clamp 4 are L-shaped, and the sample is clamped between the upper clamp 1 and the lower clamp 4. The bottom end face of the sample abuts against the upper clamp 1, and the top end face abuts against the lower clamp 4.

[0058] Specifically, the long side of the L-shaped structure serves as the sample clamping section, while the short side serves as the force transmission transition section. This structure boasts high rigidity and a short force transmission path, reducing energy loss and deformation during force transmission. The sample is clamped between the upper and lower clamps, with its bottom face abutting against the L-shaped stepped surface of the upper clamp 1 and its top face abutting against the L-shaped stepped surface of the lower clamp 4, forming an axial positioning constraint. Simultaneously, the internal space of the upper and lower clamps provides lateral constraint on the sample from all sides, limiting lateral displacement and achieving omnidirectional positioning to ensure that the sample's force center aligns with its loading center.

[0059] Preferred, such as Figure 1 As shown, both the first tension chuck 2 and the second tension chuck 5 are equipped with universal joints 10.

[0060] Specifically, universal joints 10 are installed on both the first tension clamp 2 and the second tension clamp 5. The flexible connection of the universal joints enables adaptive compensation and multi-angle transmission of the loading force. The universal joint 10 adopts a cross-shaft or ball joint structure, allowing for a certain angle of deflection and slight torsion. During loading, if the upper and lower clamps are not concentric or there is a deviation in the centering of the sample, the universal joint 10 can adaptively compensate for this deviation through its own deflection, ensuring that the loading force is always transmitted along the vertical centerline of the sample, avoiding deviation in the direction of the loading force, and thus eliminating the generation of additional torque and bending loads. At the same time, the flexible connection of the universal joint can absorb instantaneous impacts and vibrations during loading, making the loading process smoother.

[0061] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0062] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0063] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0064] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0065] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A fixing and clamping device for testing the shear properties of carbon fiber composite materials, characterized in that, include: Upper clamp (1); The first tension chuck (2) is disposed on the upper clamp (1); The first guide post (3) has one end connected to the upper clamp (1); The lower clamp (4) has the other end of the first guide post (3) slidably connected to the lower clamp (4); The second tension chuck (5) is mounted on the lower clamp (4); The second guide post (6) has one end connected to the lower clamp (4) and the other end slidably connected to the upper clamp (1); The calibration mechanism (7) is provided inside the upper clamp (1) and the lower clamp (4) for calibrating the sample; The clamping mechanism (9) is provided inside both the upper clamp (1) and the lower clamp (4) for clamping the sample.

2. The fixing and clamping device for testing the shear properties of carbon fiber composite materials according to claim 1, characterized in that, Both the first guide post (3) and the second guide post (6) include: The first fixed shaft (31) has one end connected to the upper clamp (1) or the lower clamp (4); A spherical positioning head (32) is disposed at the other end of the first fixed shaft (31); The second fixed shaft (33) is slidably connected inside the upper clamp (1) or the lower clamp (4); A spherical bushing (34) is disposed at the end of the second fixed shaft (33) and is hinged to the spherical positioning head (32).

3. The fixing and clamping device for testing the shear properties of carbon fiber composite materials according to claim 1, characterized in that, The calibration mechanism (7) includes: The first movable plate (701) is slidably connected inside the upper clamp (1); A first fixed plate (702) is disposed on the first movable plate (701); The second movable plate (703) is slidably connected to the first movable plate (701); The third fixed shaft (704) is fixed on the first fixed plate (702) and slidably connected to the second movable plate (703); The first roller (705) is rotatably connected to the second movable plate (703) and is used to abut the sample; The second fixing plate (706) is disposed inside the upper clamp (1); The first spring (707) has one end connected to the first movable plate (701) and the other end connected to the second fixed plate (706).

4. The fixing and clamping device for testing the shear properties of carbon fiber composite materials according to claim 3, characterized in that, The calibration mechanism (7) further includes: The third moving plate (708) is slidably connected inside the lower clamp (4); The second roller (709) is rotatably connected to the third movable plate (708) and is used to abut the sample; The third fixing plate (710) is disposed inside the lower clamp (4); The second spring (711) has one end connected to the third movable plate (708) and the other end connected to the third fixed plate (710).

5. The fixing and clamping device for testing the shear properties of carbon fiber composite materials according to claim 4, characterized in that, The third moving plate (708), the second roller (709), the third fixed plate (710), and the second spring (711) are all provided in multiple sets, and the included angle between two adjacent sets of the third moving plates (708) is adapted to the angle of the sample contact portion.

6. The fixing and clamping device for testing the shear properties of carbon fiber composite materials according to claim 1, characterized in that, Both the upper clamp (1) and the lower clamp (4) are provided with arc-shaped parts (8), and stress relief grooves (81) are provided on the arc-shaped parts (8). Cross-shaped ribs (82) are provided inside the stress relief grooves (81).

7. The fixing and clamping device for testing the shear properties of carbon fiber composite materials according to claim 1, characterized in that, The clamping mechanism (9) includes: The fourth movable plate (901) is slidably connected inside the upper clamp (1) and the lower clamp (4); A clamping block (902) is disposed on the fourth movable plate (901); The slider (903) is slidably connected inside the upper clamp (1) and the lower clamp (4); A hinge rod (904) has one end hinged to the clamping block (902) and the other end hinged to the slider (903); A fourth fixed plate (905) is disposed on the fourth movable plate (901); The fifth fixing plate (906) is disposed inside the upper clamp (1) and the lower clamp (4); The fourth fixed shaft (907) has one end connected to the fourth fixed plate (905) and the other end passing through the fifth fixed plate (906) and slidably connected to the fifth fixed plate (906); The third spring (908) has one end abutting against the fourth fixing plate (905) and the other end abutting against the fifth fixing plate (906).

8. The fixing and clamping device for testing the shear properties of carbon fiber composite materials according to claim 7, characterized in that, The upper clamp (1) and the lower clamp (4) are each provided with at least two sets of clamping mechanisms (9), and the edge of the clamping block (902) is arc-shaped.

9. The fixing and clamping device for testing the shear properties of carbon fiber composite materials according to claim 1, characterized in that, The upper clamp (1) and the lower clamp (4) are both L-shaped, and the sample is clamped between the upper clamp (1) and the lower clamp (4). The bottom end face of the sample abuts against the upper clamp (1), and the top end face abuts against the lower clamp (4).

10. The fixing and clamping device for testing the shear properties of carbon fiber composite materials according to claim 1, characterized in that, Both the first tension chuck (2) and the second tension chuck (5) are equipped with universal joints (10).

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