Edge impact post compression fixture

Abstract

The present application relates to the technical field of composite material testing, and particularly relates to a compression clamp after edge impact. The clamp comprises: a support seat for supporting a test piece to be compressed after edge impact, the test piece being a composite laminated plate; two clamping plates for clamping the test piece, each of the clamping plates being provided with a first avoiding groove and a second avoiding groove facing the test piece, the first avoiding groove being used for avoiding a protrusion formed by the test piece after edge impact, and the second avoiding groove being used for avoiding a strain gauge installed on the surface of the test piece. The scheme can meet the requirements of end loading compression test after edge impact.

Description

Technical Field

[0001] This invention relates to the field of composite material testing technology, and in particular to a compression clamp after edge impact. Background Technology

[0002] Compression-after-impact (CAI) testing is an important test in the field of composite material testing (such as aerospace composite materials). By measuring the compressive properties of composite laminates after impact, it assesses the impact resistance and damage tolerance of the composite material.

[0003] In the aerospace industry, resistance to impact damage is generally expressed as compressive strength after low-speed impact, and it has been widely used in the evaluation of the toughness of resin-based composite materials.

[0004] However, experimental research on compression after edge impact is still in its early stages, so it is necessary to design a compression fixture for compression tests after edge impact. Summary of the Invention

[0005] This invention provides a compression fixture after edge impact, which can meet the requirements of edge impact end-load compression test.

[0006] This invention provides a compression fixture after edge impact, comprising:

[0007] A support base is used to support a specimen that has undergone edge impact and is to be compressed; the specimen is a composite laminate.

[0008] Two clamping plates are used to hold the specimen. Each clamping plate is provided with a first clearance groove and a second clearance groove facing the specimen. The first clearance groove is used to avoid the protrusion formed by the specimen after edge impact, and the second clearance groove is used to avoid the strain gauge installed on the surface of the specimen.

[0009] In one possible design, the support base includes a first support portion located in the horizontal direction and a second support portion located in the vertical direction, the first support portion and the second support portion being connected to form an L-shaped structure;

[0010] The specimen is placed on the first support, and one of the clamps is fixed on the second support.

[0011] In one possible design, one of the clamps is fixed to the second support by bolts.

[0012] In one possible design, a pad is also included, which is fixed to the first support, and the specimen is placed on the pad so that the height of the specimen exceeds the height of the second support by adjusting the height of the pad.

[0013] In one possible design, the pad is fixed to the first support by bolts.

[0014] In one possible design, the first clearance groove is an arc-shaped groove.

[0015] In one possible design, the second clearance groove is a rectangular groove that is connected in an interlocking manner.

[0016] In one possible design, each of the clamps is provided with serrations facing the specimen, and when the specimen is clamped by two of the clamps, the serrations are vertical.

[0017] In one possible design, one of the clamping plates is provided with a positioning groove facing the specimen, and the other clamping plate is provided with a positioning post facing the specimen, wherein the positioning post is inserted into the positioning groove when the two clamping plates clamp the specimen.

[0018] In one possible design, the two clamps are fixed together by bolts.

[0019] This invention provides a compression fixture after edge impact. By setting two clamping plates for holding the specimen, the inner surface of each clamping plate is provided with a first clearance groove for avoiding the protrusion formed by the specimen after edge impact and a second clearance groove for avoiding strain gauges installed on the surface of the specimen. In this way, the force loaded at the end of the specimen can be accurately transmitted to the working section, thereby making it convenient and quick to test the strength and modulus of the specimen after edge impact compression, and meeting the requirements of the edge impact end loading compression test. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the structure of an edge impact compression fixture provided in an embodiment of the present invention;

[0022] Figure 2 yes Figure 1 A schematic diagram of an explosion of a compression clamp after an edge impact.

[0023] Figure 3 yes Figure 1 Another schematic diagram of the explosion of the compression clamp after the edge impact is shown.

[0024] Figure label:

[0025] 10 - Specimen;

[0026] 101 - Protrusion;

[0027] 1-Support base;

[0028] 11-First support section;

[0029] 12-Second support section;

[0030] 2-Clamping plate;

[0031] 21-First clearance groove;

[0032] 22-Second clearance groove;

[0033] 23-Sawtooth;

[0034] 24-Positioning groove;

[0035] 25 - Positioning post;

[0036] 3-Plate;

[0037] 4- Bolts. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0039] like Figure 1-3 As shown, one embodiment of the present invention provides a compression clamp after edge impact. The clamp includes a support base 1 and two clamping plates 2, wherein:

[0040] Support 1 is used to support the specimen 10 to be compressed after edge impact. Specimen 10 is a composite laminate.

[0041] Two clamping plates 2 are used to clamp the specimen 10. Each clamping plate 2 is provided with a first clearance groove 21 and a second clearance groove 22 facing the specimen 10. The first clearance groove 21 is used to avoid the protrusion 101 formed by the specimen 10 after edge impact. The second clearance groove 22 is used to avoid the strain gauge (not shown in the figure) installed on the surface of the specimen 10.

[0042] In this embodiment, by setting two clamping plates 2 for holding the specimen 10, the inner surface of each clamping plate 2 is provided with a first clearance groove 21 for avoiding the protrusion 101 formed by the specimen 10 after edge impact and a second clearance groove 22 for avoiding the strain gauge installed on the surface of the specimen 10. In this way, the force loaded at the end of the specimen 10 can be accurately transmitted to the working section, thereby making it convenient and quick to test the strength and modulus of the specimen 10 after edge impact compression, and meeting the requirements of the end loading compression test after edge impact.

[0043] In one embodiment of the present invention, the support base 1 includes a first support portion 11 located in the horizontal direction and a second support portion 12 located in the vertical direction. The first support portion 11 and the second support portion 12 are connected to form an L-shaped structure.

[0044] The specimen 10 is placed on the first support part 11, and one of the clamps 2 is fixed on the second support part 12.

[0045] In this embodiment, by setting the support base 1 as an L-shaped integral structure, the overall structure of the support base 1 can be made more compact.

[0046] Of course, the two clamps 2 can also be supported by external support devices, which is not limited here.

[0047] In one embodiment of the present invention, one of the clamping plates 2 is fixed to the second support portion 12 by bolts 4.

[0048] In one embodiment of the present invention, a pad 3 is also included. The pad 3 is fixed on the first support portion 11, and the specimen 10 is disposed on the pad 3 so that the height of the specimen 10 exceeds the height of the second support portion 12 by adjusting the height of the pad 3.

[0049] In this embodiment, by setting the pad 3, the height of the specimen 10 can be easily adjusted so that the height of the specimen 10 exceeds the height of the second support part 12, thereby facilitating the compression test.

[0050] In one embodiment of the present invention, the pad 3 is fixed to the first support 11 by bolts 4.

[0051] In one embodiment of the present invention, the first clearance groove 21 is an arc-shaped groove.

[0052] It is understandable that the shape of the first clearance groove 21 is adapted to the shape of the protrusion 101 formed by edge impact, so the shape of the first clearance groove 21 is not limited here.

[0053] In one embodiment of the present invention, the second clearance groove 22 is a rectangular groove that is connected to each other in an interlocking manner.

[0054] It is known that since the specimen 10 is a protrusion 101 formed by edge impact, in order to better measure the modulus of the working section, multiple strain gauges need to be distributed in different unknowns of the working section. Therefore, the second clearance groove 22 can be set as a rectangular groove that is interconnected with each other.

[0055] In one embodiment of the present invention, each clamping plate 2 is provided with serrations 23 facing the specimen 10. When the two clamping plates 2 clamp the specimen 10, the serrations 23 are vertical.

[0056] In this embodiment, by providing serrations 23 on the inner surface of the clamping plate 2, it is possible to prevent the specimen 10 from becoming unstable during the compression process and to reduce the contact area between the clamping plate 2 and the specimen 10, thereby reducing the test error caused by friction. Furthermore, by making the serrations 23 vertical, the friction between the clamping plate 2 and the specimen 10 can be further reduced.

[0057] In one embodiment of the present invention, one clamping plate 2 is provided with a positioning groove 24 facing the specimen 10, and the other clamping plate 2 is provided with a positioning post 25 facing the specimen 10. When the two clamping plates 2 clamp the specimen 10, the positioning post 25 is inserted into the positioning groove 24.

[0058] In this embodiment, by setting a positioning groove 24 on the inner surface of one clamping plate 2 and a positioning post 25 on the inner surface of another clamping plate 2, the initial positioning of the positioning groove 24 and the positioning post 25 facilitates the clamping of the specimen 10.

[0059] In one embodiment of the present invention, the two clamps 2 are fixed by bolts 4.

[0060] The following describes the workflow of the compression fixture after edge impact.

[0061] Place a clamping plate 2 on the inner surface of the second support part 12 and fix it with bolts 4;

[0062] Place the pad 3 on the first support part 11 and fix it with bolts 4;

[0063] Place the specimen 10 with the strain gauges attached vertically on the pad 3;

[0064] The other clamp 2 is fastened to the previous clamp 2, so that the protrusion 101 is located in the first relief groove 21, and the part of the strain gauge attached to the specimen 10 is located in the second relief groove 22.

[0065] The positioning groove 24 and the positioning column 25 are fitted together, and the two clamping plates 2 are fixed with bolts 4 to complete the installation of the specimen 10;

[0066] The fixture was placed on the pressure plate of the testing machine for an end-load compression test.

[0067] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A compression clamp after edge impact, characterized in that, include: Support base (1) is used to support the specimen (10) to be compressed after edge impact, the specimen (10) being a composite laminate; Two clamping plates (2) are used to clamp the specimen (10). Each clamping plate (2) is provided with a first clearance groove (21) and a second clearance groove (22) facing the specimen (10). The first clearance groove (21) is used to avoid the protrusion (101) formed by the specimen (10) after edge impact. The second clearance groove (22) is used to avoid the strain gauge installed on the surface of the specimen (10). The support base (1) includes a first support part (11) located in the horizontal direction and a second support part (12) located in the vertical direction. The first support part (11) and the second support part (12) are connected to form an L-shaped structure. The specimen (10) is disposed on the first support (11), and one of the clamps (2) is fixed on the second support (12); It also includes a pad (3), which is fixed on the first support (11), and the specimen (10) is placed on the pad (3) so that the height of the specimen (10) exceeds the height of the second support (12) by adjusting the height of the pad (3). The first clearance groove (21) is an arc-shaped groove; The second clearance groove (22) is a rectangular groove that is interlocked; Each of the clamping plates (2) is provided with serrations (23) facing the specimen (10). When the two clamping plates (2) clamp the specimen (10), the serrations (23) are vertical. One of the clamping plates (2) is provided with a positioning groove (24) facing the specimen (10), and the other clamping plate (2) is provided with a positioning post (25) facing the specimen (10). When the two clamping plates (2) clamp the specimen (10), the positioning post (25) is inserted into the positioning groove (24).

2. The edge impact compression clamp according to claim 1, characterized in that, One of the clamps (2) is fixed to the second support (12) by bolts (4).

3. The edge impact compression clamp according to claim 1, characterized in that, The pad (3) is fixed to the first support (11) by bolts (4).

4. The edge impact compression clamp according to any one of claims 1-3, characterized in that, The two clamps (2) are fixed by bolts (4).

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