Tensile test clamping structure of fiber reinforced sandwich material

Abstract

The utility model relates to the technical field of clamping tools, and discloses a tensile test clamping structure of a fiber reinforced sandwich material, which comprises a first chuck and a second chuck, the first chuck and the second chuck are respectively provided with a clamping end and a mounting end; wherein the clamping end of the first chuck and the clamping end of the second chuck are oppositely arranged, clamping grooves are correspondingly formed in the clamping ends of the first chuck and the second chuck respectively, and the clamping grooves are used for clamping the ends of a sandwich material sample; the mounting ends of the first chuck and the second chuck are respectively assembled on a chuck of a tensile testing machine. According to the structure, the first chuck and the second chuck are designed, and the clamping grooves are respectively formed in the clamping ends, so that the end part of a sandwich material sample can be quickly and stably clamped, the clamping process is simplified, and the efficiency of a test preparation stage is improved. The clamping structure can quickly and accurately clamp a plurality of samples, and is very suitable for large and medium batch tensile tests.

Description

Technical Field

[0001] This utility model relates to the field of clamping tooling technology, specifically to a clamping structure for tensile testing of fiber-reinforced sandwich materials. Background Technology

[0002] Currently, widely used testing standards and methods generally rely on double-sided clamping technology to fix test specimens. While this technology is simple and easy to operate, it has revealed significant problems in practical applications.

[0003] Specifically, the clamps apply a continuous load to the skins on both sides of the test specimen during pre-tightening and clamping. However, because the core material (such as foam, paper honeycomb, or aluminum honeycomb) has lower compressive strength compared to the inner and outer skins, this load transfer method easily leads to extrusion deformation or damage of the core material. Once the sandwich structure is damaged during clamping, the state of the test specimen deviates from the original structure and state of the test product, thus making the test data unable to accurately reflect the true tensile mechanical properties of the test product.

[0004] To avoid damage to the sandwich layer, theoretically, only a small load can be applied to the inner and outer skins during clamping. However, in practice, this approach faces the challenge of ineffective specimen clamping. Due to the insufficient load, the specimen is prone to sliding up and down during the test, which not only introduces data deviations but may even lead to the termination of the test.

[0005] In summary, existing clamping techniques for tensile testing of fiber-reinforced sandwich materials have significant shortcomings. They fail to ensure the integrity of the test specimens and cannot guarantee the accuracy and reliability of the test data. Therefore, there is an urgent need to develop a novel clamping technique that can effectively clamp the specimens while protecting the integrity of the sandwich structure, thereby accurately evaluating the tensile mechanical properties of fiber-reinforced sandwich materials. Utility Model Content

[0006] In order to overcome the defects of the prior art, the purpose of this utility model is to provide a tensile test clamping structure for fiber reinforced sandwich materials, so as to solve the technical problem of how to improve the clamping ability of sandwich materials in the prior art.

[0007] This utility model is achieved through the following technical solution:

[0008] This utility model provides a tensile testing clamping structure for fiber-reinforced sandwich materials, including a first clamp and a second clamp; the first clamp and the second clamp are respectively provided with a clamping end and a mounting end; wherein the clamping ends of the first clamp and the second clamp are arranged opposite to each other, and the first clamp and the second clamp are respectively provided with clamping grooves at the clamping ends, the clamping grooves being used to clamp the end of the sandwich material sample; the mounting ends of the first clamp and the second clamp are respectively used to be assembled onto the clamps of a tensile testing machine.

[0009] Preferably, the clamping slots of the first chuck and the second chuck are positioned opposite each other.

[0010] Preferably, the first chuck and the second chuck have the same structure, wherein the first chuck includes a clamping block and a pressing block;

[0011] The clamping groove is disposed between the clamping block and the pressure block, and the clamping block and the pressure block are fixedly disposed by a number of fastening screws.

[0012] Furthermore, a pressure plate is also provided in the clamping groove to fill the gap of the core material sample in the clamping groove.

[0013] Furthermore, the clamping block includes a clamping plate and a clamping plate;

[0014] The clamping plate has a clamping cavity inside, and the clamping plate covers the pressure block. The clamping cavity forms a clamping groove between the clamping plate and the pressure block. The ends of the pressure plate and the core material sample are clamped in the clamping cavity.

[0015] Furthermore, the clamping plate is provided with several alignment holes around the clamping cavity; several fastening screws are fixed to the pressure block through the alignment holes.

[0016] Furthermore, the pressure block is provided with several fastening through holes at the positions corresponding to several alignment holes;

[0017] Several fastening screws pass through several alignment holes and threads into several fastening through holes.

[0018] Furthermore, the pressure block includes a base plate, on which a protrusion is provided at a position corresponding to the clamping cavity. The clamping cavity is covered and wrapped around the protrusion. The ends of the pressure plate and the core material sample are placed on the protrusion and pressed onto the pressure plate and the core material sample through the clamping cavity.

[0019] Furthermore, the protrusions, pressure plates, and clamping cavities have the same shape, with the protrusions and pressure plates being the same size, and the clamping cavity being larger than the protrusions and pressure plates.

[0020] Furthermore, the depth of the clamping cavity is equal to the overall thickness of the protrusion, pressure plate, and core material sample stacked together.

[0021] Compared with the prior art, the present invention has the following beneficial technical effects:

[0022] This invention provides a clamping structure for tensile testing of fiber-reinforced sandwich materials. By designing a first and second clamp, and providing clamping grooves at their respective clamping ends, the ends of the sandwich material specimen can be quickly and securely clamped. This design simplifies the clamping process and improves the efficiency of the test preparation stage. The clamping groove design fully considers the characteristics of the sandwich material, ensuring that the specimen will not be damaged due to uneven force during clamping. Through reasonable clamping force and clamping method, slippage of the specimen during the tensile test is effectively prevented, ensuring the accuracy and reliability of the test data. This clamping structure can quickly and accurately clamp multiple specimens, making it ideal for large and medium batch tensile tests.

[0023] Furthermore, the clamping slots of the first and second clamps are positioned opposite each other, ensuring precise alignment of the specimen during clamping and effectively eliminating test errors caused by specimen position deviations. The oppositely positioned clamping slots also ensure uniform load distribution on the specimen during clamping. This helps prevent localized damage to the specimen due to uneven stress, thereby improving the accuracy and repeatability of test data.

[0024] Furthermore, a clamping groove is positioned between the clamping block and the pressure block, and its width and depth can be flexibly adjusted according to the size and shape of the sample. By changing the relative position between the clamping block and the pressure block, samples of different sizes can be accommodated, improving the applicability of the clamping structure. The clamping block and the pressure block are fixed in place by several fastening screws, ensuring the stability and reliability of the clamping groove during the clamping process. The fastening screws not only provide sufficient clamping force but also prevent the clamping block and the pressure block from loosening or deforming during the test, thereby ensuring stable clamping of the sample.

[0025] Furthermore, the clamping plates fill the gaps in the clamping grooves of the sandwich material specimen, ensuring a tight fit between the specimen and the grooves during clamping. This tight fit helps reduce slippage or displacement of the specimen during tensile testing, improving clamping accuracy and the precision of test data. The addition of clamping plates helps optimize load distribution on the specimen. By adjusting the position and number of clamping plates, a uniform load distribution can be ensured on the specimen during clamping, thus avoiding localized overload or damage. The soft material or appropriate hardness design of the clamping plates protects the specimen from damage during clamping. This protective mechanism helps ensure the integrity and accuracy of the specimen, thereby improving the reliability of test data.

[0026] Furthermore, the clamping block consists of a clamping plate and a holding plate, a double-layer structure design that enhances the rigidity and stability of the clamping structure. In tensile tests, this rigid structure better resists specimen deformation and slippage, ensuring the accuracy of test data. The clamping cavity forms a clamping groove between the clamping plate and the pressure block; this design allows the depth and shape of the clamping groove to be adjusted as needed. By changing the relative position of the clamping plate and the pressure block, or by selecting pressure blocks of different thicknesses, it is possible to flexibly adapt to specimens of different sizes, improving the versatility and applicability of the clamping structure. Both the pressure plate and the ends of the core material specimen are clamped within the clamping cavity; this design ensures the stability and accuracy of the specimen during clamping. The precise dimensions and shape of the clamping cavity help reduce specimen slippage or displacement during tensile tests, thereby improving clamping accuracy and the reliability of test data.

[0027] Furthermore, the clamping plate is provided with several alignment holes around the clamping cavity. These alignment holes not only provide installation positions for the fastening screws but also ensure precise alignment between the clamping plate and the pressure block. This precise alignment helps reduce positional deviation of the specimen during clamping, improving clamping accuracy and the accuracy of test data. The fastening screws securely fix the clamping plate to the pressure block through the alignment holes, forming a stable clamping structure. This structure effectively resists specimen deformation and slippage during tensile testing, ensuring smooth test execution and reliable data.

[0028] Furthermore, the pressure block is provided with a fastening through hole corresponding to the alignment hole, so that the fastening screw can pass smoothly through the alignment hole and be threaded into the fastening through hole, ensuring that the fastening connection between the clamping plate and the pressure block is reliable and can effectively prevent the sample from slipping or deforming during the tensile test.

[0029] Furthermore, the protrusions on the base plate, corresponding to the clamping cavity, provide a stable support surface for the sandwich material specimen and the clamping plate. This design enhances the stability of the clamping structure, helping to reduce slippage or deformation of the specimen during tensile testing, thereby improving the accuracy of test data. The precise positioning and dimensional design of the protrusions ensures that the ends of the sandwich material specimen can be accurately placed on the protrusions and clamped by the clamping cavity. This design optimizes specimen positioning, reduces positional deviations, and ensures the stability and consistency of the specimen during tensile testing. The mating design of the protrusions and the clamping cavity allows the clamping plate to uniformly press against the sandwich material specimen. This uniform pressing helps improve clamping accuracy and reduces stress concentration and the risk of damage to the specimen during clamping.

[0030] Furthermore, the same shape design helps optimize stress distribution on the specimen during clamping. The uniform support of the protrusions and pressure plates reduces stress concentration at the specimen edges, while the larger cavity of the clamping chamber provides additional space to disperse stress, reducing the risk of specimen damage.

[0031] Furthermore, the depth of the clamping cavity is precisely designed to be equal to the overall thickness of the protrusions, pressure plates, and core material specimens stacked together. This design ensures that the specimen can be tightly and uniformly fixed during clamping. Because the depth of the clamping cavity matches the overall thickness of the specimen, the specimen is less prone to slippage or tilting during tensile testing, thereby improving the accuracy and reliability of the test. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the tensile test clamping structure of the fiber-reinforced sandwich material in an embodiment of this utility model;

[0033] Figure 2 This is a schematic diagram of the internal structure of the first chuck in an embodiment of the present invention;

[0034] Figure 3 This is a schematic diagram of the first and second clamps in an embodiment of the present invention;

[0035] Figure 4 This is a schematic diagram showing the disassembly of the first clamp in an embodiment of the present invention;

[0036] In the figure: 1. First chuck; 2. Sandwich material sample; 3. Second chuck; 11. Clamping block; 12. Pressure block; 13. Pressure plate; 14. Fastening screw; 111. Clamping block plate; 112. Clamping plate; 113. Clamping cavity; 114. Alignment hole; 115. Set screw hole; 121. Base plate; 122. Protrusion block; 123. Fastening through hole. Detailed Implementation

[0037] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of 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 should fall within the protection scope of the present invention.

[0038] The purpose of this invention is to provide a tensile test clamping structure for fiber-reinforced sandwich materials, so as to solve the technical problem of how to improve the clamping ability of sandwich materials in the prior art.

[0039] The present invention will now be described in further detail with reference to the accompanying drawings:

[0040] See Figure 1 and Figure 3 In one embodiment of this utility model, a tensile test clamping structure for fiber-reinforced sandwich material is provided, including a first clamp 1 and a second clamp 3; the first clamp 1 and the second clamp 3 are respectively provided with a clamping end and an mounting end; wherein the clamping ends of the first clamp 1 and the second clamp 3 are arranged opposite to each other, and the first clamp 1 and the second clamp 3 are respectively provided with clamping grooves at the clamping ends, the clamping grooves being used to clamp the end of the sandwich material sample 2; the mounting ends of the first clamp 1 and the second clamp 3 are respectively used to be assembled onto the clamps of a tensile testing machine.

[0041] Specifically, the clamping slots of the first chuck 1 and the second chuck 3 are positioned relative to each other.

[0042] Specifically, the first chuck 1 and the second chuck 3 have the same structure, wherein the first chuck 1 includes a clamping block 11 and a pressing block 12, as shown below. Figure 2 As shown;

[0043] The clamping groove is disposed between the clamping block 11 and the pressure block 12, and the clamping block 11 and the pressure block 12 are fixedly disposed by a number of fastening screws 14.

[0044] The clamping groove is also equipped with a pressure plate 13, which is used to fill the gap of the core material sample 2 in the clamping groove.

[0045] Specifically, according to Figure 4 As shown, the clamping block 11 includes a clamping block plate 111 and a clamping plate 112;

[0046] The clamping plate 111 has a clamping cavity 113 inside, and the clamping plate 111 covers the pressure block 12. The clamping cavity 113 forms a clamping groove between the clamping plate 111 and the pressure block 12. The ends of the pressure plate 13 and the core material sample 2 are both clamped in the clamping cavity 113.

[0047] The clamping plate 111 is provided with a number of alignment holes 114 around the clamping cavity 113; a number of fastening screws 14 are fixed to the pressure block 12 through the number of alignment holes 114.

[0048] Among them, the pressure block 12 is provided with a number of fastening through holes 123 at the positions corresponding to a number of alignment holes 114;

[0049] Several fastening screws 14 are threaded through several alignment holes 114 and several fastening through holes 123.

[0050] Specifically, according to Figure 4As shown, the pressure block 12 includes a base plate 121, and a protrusion 122 is provided on the base plate 121 at a position corresponding to the clamping cavity 113. The clamping cavity 113 covers and wraps around the protrusion 122. The ends of the pressure plate 13 and the core material sample 2 are placed on the protrusion 122 and are pressed onto the pressure plate 13 and the core material sample 2 by the clamping cavity 113.

[0051] The protrusion 122, the pressure plate 13, and the clamping cavity 113 have the same shape. The protrusion 122 and the pressure plate 13 are the same size, and the size of the clamping cavity 113 is larger than that of the protrusion 122 and the pressure plate 13.

[0052] The depth of the clamping cavity 113 is equal to the overall thickness of the protrusion 122, the pressure plate 13, and the core material sample 2 stacked together.

[0053] In this embodiment, the main components of the clamping structure are manufactured using machining processes. The raw material is 304 stainless steel. The clamping block 11 has a wall thickness of 13mm, the pressure block 12 has a wall thickness of 5mm, and the pressure plate 13 has a wall thickness of 1mm. The fastening through hole 123 is a through hole, and it is fixed to the clamping block with M6*35 hexagonal screws and nuts. Appropriate rounding treatment is applied to the right angle and arc contact areas of the tooling to prevent the integrity of the sample block from being affected by bumps during installation. The tooling in the clamping area of ​​the testing machine is roughened with knurled keys to ensure firm and reliable clamping.

[0054] Install the clamping plate 112 of clamping block 11 onto the clamping head of the tensile testing machine. Secure the clamping block by rotating the handle on the clamping head. Place one end of the core material sample 2 (and the other end similarly) into the clamping groove of clamping block 11. Then place the pressure plate 13 into the clamping groove of the clamping block. Finally, align the protrusion 122 of pressure block 12 with the clamping cavity 113 of clamping block 11 and install it. Secure all three components and the sample with fastening screws 14. During fixing, the height of the clamping cavity can be adjusted according to the thickness of the test sample. When tightening until the inner and outer skins of the sample contact clamping block 11 and pressure block 12, lightly tighten the fastening screws 14 to ensure that there is no wobble in the thickness direction of the sample. At this point, the test sample is properly clamped and will not be damaged or deformed due to the clamping process. After the tensile test begins, the test sample will not slip, fall, or cause other problems due to clamping and compression.

[0055] A 0.5mm gap is left between the sandwich material sample and the side contact circumference of the clamping cavity, which can effectively ensure that the test sample does not generate abnormal compression when clamped, and also avoids bumps during the clamping test, thus ensuring the product condition of the sample before and during the test.

[0056] In summary, this invention provides a clamping structure for tensile testing of fiber-reinforced sandwich materials. By designing a first clamp and a second clamp, and providing clamping grooves at the clamping ends, the ends of the sandwich material specimens can be quickly and securely clamped. This design simplifies the clamping process and improves the efficiency of the test preparation stage. The design of the clamping grooves fully considers the characteristics of the sandwich material, ensuring that the specimens will not be damaged due to uneven force during clamping. Through reasonable clamping force and clamping method, slippage of the specimens during the tensile test is effectively prevented, ensuring the accuracy and reliability of the test data. This clamping structure can quickly and accurately clamp multiple specimens, making it very suitable for large and medium batch tensile tests.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and not to limit it. Although the utility model has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of this utility model. Any modifications or equivalent substitutions that do not depart from the spirit and scope of this utility model should be covered within the protection scope of the claims of this utility model.

Claims

1. A tensile test clamping structure of a fiber-reinforced sandwich material, characterized by, The utility model relates to a kind of clamping heads for sandwich material, including first chuck (1) and second chuck (3);The first chuck (1) and second chuck (3) are respectively provided with clamping end and mounting end;Wherein the clamping end of first chuck (1) and second chuck (3) is oppositely arranged, and the clamping end of first chuck (1) and second chuck (3) is respectively provided with clamping groove, the clamping groove is used to clamp in the end of sandwich material sample (2);The mounting end of first chuck (1) and second chuck (3) is used to be respectively assembled on the chuck of tensile testing machine.

2. A tensile test holder for a fiber reinforced sandwich material according to claim 1, characterized in that The clamping groove of the first chuck (1) and the second chuck (3) is oppositely arranged.

3. A tensile test holder for a fiber reinforced sandwich material according to claim 1, characterized in that The first chuck (1) and the second chuck (3) are the same structure, wherein the first chuck (1) includes clamping block (11) and pressing block (12); The clamping groove is arranged between the clamping block (11) and the pressing block (12), and the clamping block (11) and the pressing block (12) are fixedly arranged by a plurality of fastening screws (14).

4. A tensile test holder for a fibre reinforced sandwich material according to claim 3, characterised in that The clamping groove is further provided with a pressing plate (13); for filling the gap of the sandwich material sample (2) in the clamping groove.

5. A tensile test holder for a fibre reinforced sandwich material according to claim 4, characterised in that The clamping block (11) includes a clamping block plate (111) and a clamping plate (112). The clamping block plate (111) is provided with a clamping cavity (113), and the clamping block plate (111) is arranged on the pressing block (12), wherein the clamping cavity (113) forms a clamping groove between the clamping block plate (111) and the pressing block (12); the end of the sandwich material sample (2) and the pressing plate (13) are clamped in the clamping cavity (113).

6. A tensile test holder for a fibre reinforced sandwich material according to claim 5, characterised in that The clamping block plate (111) is provided with a plurality of positioning holes (114) around the position of the clamping cavity (113); a plurality of fastening screws (14) are fixed on the pressing block (12) through the plurality of positioning holes (114).

7. A tensile test holder for a fibre reinforced sandwich material according to claim 6, characterised in that The pressing block (12) is provided with a plurality of fastening through holes (123) corresponding to the positions of the plurality of positioning holes (114). A plurality of fastening screws (14) are screwed through the plurality of positioning holes (114) and the plurality of fastening through holes (123).

8. A tensile test holder for a fiber reinforced sandwich material according to claim 5, characterized in that The pressing block (12) includes a bottom plate (121), and the bottom plate (121) is provided with a protruding block (122) corresponding to the position of the clamping cavity (113); the clamping cavity (113) is arranged on the protruding block (122); the end of the sandwich material sample (2) and the pressing plate (13) are placed on the protruding block (122), and are pressed on the pressing plate (13) and the sandwich material sample (2) by the clamping cavity (113).

9. A tensile test holder for a fibre reinforced sandwich material according to claim 8, characterised in that The protruding block (122), the pressing plate (13) and the clamping cavity (113) are the same shape, wherein the size of the protruding block (122) and the pressing plate (13) is the same, and the size of the cavity of the clamping cavity (113) is larger than the size of the protruding block (122) and the pressing plate (13).

10. A tensile test holder for a fiber reinforced sandwich material according to claim 8, characterized in that The depth of the clamping cavity (113) is equal to the overall thickness of the protruding block (122), the pressing plate (13) and the sandwich material sample (2).

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