Device and method for testing shear strength of composite board

Abstract

The invention discloses a device and a method for testing the shear strength of a composite board. The device comprises a base, a fixed mold and a cutting tool, the base is provided with a die cavity and a cutting tool groove, the cutting tool groove is communicated with the die cavity, and the base is further provided with an operation opening communicated with the die cavity. The fixed die is installed in the die cavity through the operation opening, the fixed die is provided with a cutting tool channel communicated with the cutting tool groove, two clamping mechanisms used for clamping the composite board are arranged in the fixed die, and the two clamping mechanisms are arranged on the two sides of the cutting tool channel respectively. The cutting tool is arranged in the cutting tool groove in a sliding mode, and the cutting tool can press the composite board downwards through the cutting tool channel. According to the shear strength testing device and method for the composite board, the stress of the downward pressure is vertically centered, the accuracy of a shear strength experiment is improved, the test method adopts two-side clamping and shearing of the sample, the sample processing requirement is greatly reduced, the operation is simple and convenient, the efficiency is high, observation can be performed during testing, the structure is simple, and the tested thickness range is wide.

Description

Technical Field

[0001] The invention relates to the technical field of layered composite plates, and in particular to a shear strength testing device and a testing method for composite plates. Background Art

[0002] Metal layered composite materials are composite materials formed by combining two or more metal components with different properties using different composite preparation processes. Since the layered composite plate combines the characteristics of each component, it has better comprehensive performance than a single plate. Interface bonding quality is an important indicator affecting the performance of metal composite materials. The interface bonding quality of metal layered composite materials is generally evaluated by interface microstructure, interface peeling strength and interface shear strength. Among them, interface shear strength can quantitatively evaluate the interface bonding quality and is widely concerned.

[0003] Interface shear strength, also known as interlaminar shear strength, refers to the maximum load parallel to the bonding surface that a composite plate can withstand per unit area. The main methods for evaluating the interface shear strength of metal layered composite materials are compression shear test and tensile shear test. Compared with the tensile shear test, the compression shear test requires simpler equipment and is relatively easy to operate at a lower cost. However, the current strength test of the compression shear test, because the force acting surface of the downward pressure is mostly on one side of the cutting tool, will introduce greater friction and result in larger experimental errors.

[0004] The shear strength test method and mold with patent number 201710323957.3 have been widely used, but because its original parts are processed into bars, the surface is not easy to polish, and the interface is processed into grooves, the processing is cumbersome and difficult to accurately control; secondly, because its mold hole is fixed, new molds need to be re-made for samples with different sample diameters. The shear strength test method with patent number 202111655561.1 has high processing requirements for shear specimens, which is not easy to prepare, and the corresponding molds need to be re-made for shear specimens of different sample sizes. The shear strength test of the composite plate with patent number CN201110049522.7 is more accurate. During the test, the shear specimens are symmetrically installed on the cutting tool and then assembled. The assembly process is more cumbersome; the samples on both sides are clamped on a cutting tool at the same time. When the punch and the pressure cover are used to lock, the sample interface is easy to deviate from the edge of the cut, resulting in inaccurate testing; the mold requires accurate and consistent sample preparation height, otherwise it is easy to tilt; in addition, the test results do not consider the influence of the weight of the cutting tool on the shear strength. Summary of the invention

[0005] Based on this, it is necessary to provide a shear strength testing device and a testing method for a composite plate to address the above problems. The testing device and method are vertically centered under pressure, easy to operate, highly efficient, observable during testing, simple in structure, and have a wide range of test thickness.

[0006] A shear strength testing device for a composite plate, comprising:

[0007] A base, wherein the base is provided with a mold cavity and a cutting tool groove, the cutting tool groove is communicated with the mold cavity, and the base is also provided with an operation port communicated with the mold cavity;

[0008] A fixed mold is installed in the mold cavity through the operation port, the fixed mold is provided with a cutting tool channel connected to the cutting tool groove, and the fixed mold is provided with two groups of clamping mechanisms for clamping the composite board, and the two groups of clamping mechanisms are respectively arranged on both sides of the cutting tool channel; and

[0009] The cutting tool is slidably disposed in the cutting tool groove, and the cutting tool can press down the composite plate through the cutting tool channel.

[0010] In one of the embodiments, a fixing member is further included, wherein the fixing member is disposed on the base and connected to the fixed mold to fix the fixed mold in the mold cavity.

[0011] In one embodiment, the cutting tool has a pressing end and a connecting end opposite to each other, the pressing end is used to press down the composite plate, and the connecting end is used to connect to a universal testing machine.

[0012] In one embodiment, the clamping mechanism includes a clamping screw and a clip. The clamping screw is rotatably mounted on the fixed mold. The head of the clamping screw passes through the fixed mold and is exposed to the outside. The clip is threadedly mounted on the clamping screw. The fixed mold is provided with a clamping surface that cooperates with the clip to clamp the composite panel.

[0013] In one of the embodiments, the fixed mold is further provided with two sets of centering mechanisms, which are respectively arranged on both sides of the cutting tool channel, and the centering mechanisms are used to preliminarily fix the composite plate.

[0014] In one embodiment, the centering mechanism includes a centering screw and two positioning plates. The centering screw is rotatably mounted on the fixed mold. The centering screw is provided with two threaded segments with opposite rotation directions. The two positioning plates are respectively threadedly mounted on the two threaded segments.

[0015] In one embodiment, the centering mechanism further includes a linkage assembly, one of the centering screws in the two sets of the centering mechanisms is an active screw, and the other centering screw is a driven screw, and the linkage assembly is used to drive the driven screw to rotate by rotating the active screw.

[0016] In one embodiment, the linkage assembly includes a linkage shaft, a first helical gear set and a second helical gear set, one end of the linkage shaft is transmission connected to the active screw through the first helical gear set, and the other end of the linkage shaft is transmission connected to the driven screw through the second helical gear set.

[0017] A method for testing the shear strength of a composite plate, using any of the above-mentioned shear strength testing devices for a composite plate, comprises the following steps:

[0018] Process the composite plate and grind it until the interface can be observed;

[0019] Two clamping mechanisms are used to clamp and fix the two composite plates in a fixed mold respectively, and the interface of the composite plate is flush with the jaws of the cutting tool channel;

[0020] Installing the fixed mold equipped with the composite board into the mold cavity through the operation port;

[0021] Installing the cutting tool into the cutting tool slot and connecting the cutting tool to the universal testing machine;

[0022] Starting the universal testing machine, pressing the cutting tool downward, the cutting tool pressing the composite plate downward through the cutting tool channel, and reading the maximum pressure value;

[0023] The shear strength of the composite plate is calculated based on the obtained maximum pressure value.

[0024] In one embodiment, the step of calculating the shear strength of the composite plate according to the obtained maximum pressure value is specifically:

[0025] The shear strength of the composite plate is calculated according to the sum of the maximum pressure value, the weight of the cutting tool and the cross-sectional area of ​​the composite plate.

[0026] The shear strength testing device and testing method of the above-mentioned composite plate have the downward pressure force vertically centered, which improves the accuracy of the shear strength experiment. The testing method uses shear specimens clamped on both sides, which greatly reduces the requirements for specimen processing. It is easy to operate, highly efficient, observable during testing, simple in structure, and has a wide range of test thickness. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the specific implementation of the present invention, the following will briefly introduce the drawings required for use in the specific implementation. In all the drawings, each element or part is not necessarily drawn according to the actual scale.

[0028] Figure 1 A schematic structural diagram of a shear strength testing device for a composite plate in one embodiment;

[0029] Figure 2 Figure 1 Schematic diagram of the structure of the middle base;

[0030] Figure 3 Figure 1 Schematic diagram of the fixed mold clamping the composite plate;

[0031] Figure 4 for Figure 1 Schematic diagram of the structure of the medium composite plate;

[0032] Figure 5 for Figure 1 Schematic diagram of the centering mechanism installed in the fixed mold;

[0033] Figure 6 for Figure 5 Schematic diagram of the threaded connection between the center positioning plate and the centering screw;

[0034] Figure 7 is a flow chart of a method for testing the shear strength of a composite plate in one embodiment;

[0035] Figure 8 1 and 2 are shear force-displacement curves of the composite plates of Example 1 and Example 2.

[0036] Reference numerals:

[0037] 1-composite plate, 2-interface, 10-base, 11-mold cavity, 12-cutting tool groove, 13-recovery groove, 14-fixed part, 20-fixed mold, 21-cutting tool channel, 22-clamping cavity, 23-clamping surface, 24-slide groove, 30-cutting tool, 32-pressing end, 34-connecting end, 40-clamping mechanism, 42-clamping screw, 44-clamping piece, 50-centering mechanism, 51-centering screw, 52-positioning plate, 53-driving screw, 54-driven screw, 60-linkage assembly, 61-linkage shaft, 62-first helical gear set, 621-first helical gear, 622-second helical gear, 623-third helical gear, 624-fourth helical gear. DETAILED DESCRIPTION

[0038] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the invention is not limited by the specific implementation disclosed below.

[0039] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation method.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0041] See also Figure 1 and Figure 2 A shear strength testing device for a composite plate in one embodiment includes a base 10 , a fixed mold 20 and a cutting tool 30 .

[0042] The base 10 is generally square, and a mold cavity 11 is provided in the middle of the base 10 , and the mold cavity 11 is used to install and fix the mold 20 . The base 10 is also provided with a cutter groove 12 , and the cutter groove 12 is communicated with the mold cavity 11 .

[0043] In one embodiment, the cutter groove 12 extends through the top surface of the base 10, and the base 10 is also provided with a recovery groove 13 connected to the mold cavity 11. The recovery groove 13 is coaxially arranged with the cutter groove 12, and the recovery groove 13 is used to recover the sample sheared during the test. The base 10 is also provided with an operation port connected to the mold cavity 11, and the operation port is located on the side wall of the base 10. The fixed mold 20 can be installed in the mold cavity 11 through the operation port.

[0044] The fixed mold 20 is installed in the mold cavity 11 through the operation port, and the outer dimensions of the fixed mold 20 are clearance-matched with the mold cavity 11. In one embodiment, the shear strength testing device for composite panels further includes a fixing member 14, which is disposed on the base 10 and connected to the fixed mold 20 to fix the fixed mold 20 in the mold cavity 11.

[0045] Specifically, the fixing member 14 is a tightening bolt, and the base 10 is provided with a mounting hole. The tightening bolt is inserted into the mounting hole, and the tightening bolt abuts against the fixed mold 20 to fix the fixed mold 20. Two groups of tightening bolts are symmetrically provided on the base 10 to ensure the stability of the fixed mold 20. The tightening bolt is designed to be a countersunk head, that is, the tightening bolt does not protrude from the bottom surface of the base 10, so that the base 10 is placed on a plane.

[0046] The fixed mold 20 is provided with a cutting tool channel 21 connected to the cutting tool groove 12. The cutting tool channel 21 and the cutting tool groove 12 are located on the same straight line so that the cutting tool 30 can pass through the cutting tool groove 12 and enter the cutting tool channel 21. Two sets of clamping mechanisms 40 are provided in the fixed mold 20. The two sets of clamping mechanisms 40 are respectively arranged on both sides of the cutting tool channel 21. The two clamping mechanisms 40 are symmetrically designed with respect to the cutting tool channel 21. The two sets of clamping mechanisms 40 clamp and fix two composite plates 1 respectively. Among them, after the composite plate 1 is clamped and fixed by the clamping mechanism 40, the interface 2 of the composite plate 1 is flush with the jaws of the cutting tool channel 21.

[0047] The cutter 30 is slidably disposed in the cutter groove 12. When the cutter 30 is inserted into the cutter channel 21, the cutter 30 can press down the composite board 1. The pressure force of the cutter 30 is vertically centered, which improves the accuracy of the shear strength test.

[0048] In one embodiment, the cutting tool 30 is generally in the shape of a long strip, and has a pressing end 32 and a connecting end 34 opposite to each other. The connecting end 34 is used to connect to a universal testing machine, and the universal testing machine drives the cutting tool 30 to rise and fall, and the pressing end 32 is used to press down the composite board 1. Specifically in this embodiment, the cutting tool 30 is a rectangular parallelepiped structure, and the cutting tool 30 and the cutting tool groove 12 are clearance-matched.

[0049] Please also read Figure 3 and Figure 4 In one embodiment, the fixed mold 20 is provided with a clamping cavity 22, and the clamping mechanism 40 is installed in the clamping cavity 22. Both ends of the clamping cavity 22 are open, and the composite board 1 can be loaded into the position of the tool channel 21 through the openings. The bottom surface of the clamping cavity 22 is a clamping surface 23, and the clamping mechanism 40 cooperates with the clamping surface 23 to clamp the composite board 1.

[0050] Specifically, the clamping mechanism 40 includes a clamping screw 42 and a clip 44. The clamping screw 42 is rotatably mounted on the fixed mold 20. The head of the clamping screw 42 passes through the top surface of the fixed mold 20 and is exposed to the outside, which can facilitate the external tool to operate the clamping screw 42 to rotate. The head of the clamping screw 42 is countersunk to avoid affecting the installation of the fixed mold 20 into the mold cavity 11. The clip 44 is arranged in the clamping cavity 22, and the clip 44 is threadedly mounted on the clamping screw 42. Therefore, the rotation of the clamping screw 42 can drive the clip 44 to rise or fall, and the clip 44 cooperates with the clamping surface 23 to clamp the composite board 1.

[0051] Please also read Figure 5 and Figure 6In one embodiment, when the clamping screw 42 rotates to drive the clamping piece 44 to descend and clamp the composite plate 1, the clamping piece 44 will swing during the rotation of the clamping screw 42 due to the clearance between the clamping piece 44 and the clamping cavity 22. The swing of the clamping piece 44 easily drives the composite plate 1 to move, causing the interface 2 of the composite plate 1 to be uneven with the jaws of the cutting tool channel 21, affecting the accuracy of the shear strength test. Therefore, a centering mechanism 50 is also provided on the fixed mold 20. The centering mechanism 50 is provided with two groups. The two groups of centering mechanisms 50 are respectively provided on both sides of the cutting tool channel 21. The centering mechanism 50 is used to initially fix the composite plate 1 to prevent the swing of the clamping piece 44 from causing the composite plate 1 to move.

[0052] On the basis of the above embodiment, further, the centering mechanism 50 includes a centering screw 51 and two positioning plates 52, the centering screw 51 is rotatably mounted on the fixed mold 20, and the two positioning plates 52 are slidably mounted on the fixed mold 20. The centering screw 51 is provided with two threaded sections with opposite rotation directions, and the two positioning plates 52 are respectively threadedly mounted on the two threaded sections. Among them, the rotation of the centering screw 51 can drive the two positioning plates 52 to move closer to or away from each other, so that the two positioning plates 52 clamp the composite plate 1 or loosen the composite plate 1.

[0053] Furthermore, one end of the centering screw 51 passes through the side wall of the fixed mold 20 so that an external tool can drive the centering screw 51 to rotate. The clamping surface 23 is provided with a slide groove 24, and two positioning plates 52 are slidably arranged in the slide groove 24, so that the positioning plates 52 can be slidably installed on the fixed mold 20. The thickness of the positioning plate 52 should be less than or equal to the thickness of the composite plate 1 to avoid interference with the subsequent clamping of the composite plate 1 by the clamping piece 44.

[0054] On the basis of the above embodiment, the centering mechanism 50 further includes a linkage assembly 60. One of the centering screws 51 in the two sets of centering mechanisms 50 is an active screw 53, and the other centering screw 51 is a driven screw 54. The linkage assembly 60 is used to drive the active screw 53 and the driven screw 54 to be connected so that the rotation of the active screw 53 can drive the driven screw 54 to rotate. At this time, the left and right parts of the fixed mold 20 are combined into an integral structure, and the cutting tool channel 21 passes through the middle of the fixed mold 20. The active screw 53 and the driven screw 54 rotate synchronously, so that the positioning plates 52 of the left and right centering mechanisms 50 can move synchronously. After the composite plate 1 is initially clamped and positioned, since the two positioning plates 52 have the same travel distance, the composite plate 1 is automatically centered in the middle of the cutting tool channel 21. At the same time, the left and right composite plates 1 are symmetrically distributed, which can ensure the accuracy of the shear strength test.

[0055] In a specific embodiment, the linkage assembly 60 includes a linkage shaft 61, a first helical gear set 62 and a second helical gear set 63. The linkage shaft 61 is rotatably mounted on the fixed mold 20, one end of the linkage shaft 61 is transmission-connected to the active screw 53 through the first helical gear set 62, and the other end of the linkage shaft 61 is transmission-connected to the driven screw 54 through the second helical gear set 63.

[0056] Specifically, the first helical gear set 62 includes a first helical gear 621 mounted on the active screw 53 and a second helical gear 622 mounted on one end of the linkage shaft 61, and the first helical gear 621 is meshed with the second helical gear 622. The second helical gear set 63 includes a third helical gear 623 mounted on the driven screw 54 and a fourth helical gear 624 mounted on the other end of the linkage shaft 61, and the third helical gear 623 is meshed with the fourth helical gear 624.

[0057] See also Figure 7 The present invention also provides a shear strength test method for a composite plate. To implement the test method, the shear strength test device for the composite plate is used. Specifically, the test method includes the following steps:

[0058] Step S110: Processing the composite plate 1 and polishing it until the interface 2 is observable.

[0059] Specifically, the composite plate 1 is processed into a square specimen, and is polished with sandpaper or pickled with a corrosive solution until the interface 2 of the composite plate 1 can be observed, so as to facilitate the subsequent flushing of the interface 2 of the composite plate 1 with the jaws of the cutting tool channel 21. Then the square specimen is linearly cut into two left and right pieces, which are used as two composite plates 1 for subsequent tests. The two composite plates 1 should be of the same size.

[0060] Step S120 : using two clamping mechanisms 40 to clamp and fix the two composite plates 1 in the fixed mold 20 respectively, so that the interface 2 of the composite plate 1 is flush with the jaw of the cutting tool channel 21 .

[0061] Specifically, the composite board 1 is placed into the fixed mold 20 through the opening of the clamping cavity 22 and placed between the two positioning plates 52 , and the position of the composite board 1 is adjusted by tools such as tweezers so that the interface 2 of the composite board 1 is flush with the jaws of the cutting tool channel 21 .

[0062] Then, a tool is used to rotate the active screw 53, and the rotation of the active screw 53 drives the rotation of the driven screw 54 through the linkage assembly 60. The rotation of the active screw 53 and the driven screw 54 realizes the mutual approach of the positioning plates 52 until the composite plate 1 is initially clamped and fixed, and the two composite plates 1 are automatically aligned in the center. Next, a tool is used to drive the clamping screw 42 to rotate, and the rotation of the clamping screw 42 can drive the clamping piece 44 to descend, and the clamping piece 44 descends to clamp and fix the composite plate 1.

[0063] Step S130: installing the fixed mold 20 with the composite board 1 into the mold cavity 11 through the operation port.

[0064] Specifically, after the composite board 1 is fixed in the fixed mold 20 , the fixed mold 20 is installed into the mold cavity 11 through the operation port, and then the tightening bolts on the base 10 are tightened to fix the fixed mold 20 in the base 10 .

[0065] Step S140: insert the cutting tool 30 into the cutting tool slot, and connect the cutting tool 30 to the universal testing machine.

[0066] Specifically, the base 10 is moved to the universal testing machine, the cutting tool 30 is installed into the cutting tool slot 12, and then the connecting end 34 of the cutting tool 30 is connected to the universal testing machine.

[0067] Step S150: start the universal testing machine, press the cutting tool 30 downward, and the cutting tool 30 presses the composite board 1 through the cutting tool channel 21, and read the maximum pressure value.

[0068] Specifically, the universal testing machine is started, and the universal testing machine drives the cutting tool 30 to descend, and the cutting tool 30 descends into the cutting tool channel 21 until it contacts the composite plate 1 and presses down the composite plate 1. As the downward pressure gradually increases, the composite plate 1 separates from the interface 2, and the maximum pressure value F in this process is read. max .

[0069] Step S160: Calculate the shear strength of the composite plate 1 according to the obtained maximum pressure value.

[0070] Specifically, the shear strength of the composite plate 1 is calculated based on the sum of the maximum pressure value, the gravity of the cutting tool 30 and the cross-sectional area of ​​the composite plate 1. The calculation formula is as follows:

[0071]

[0072] Among them, F max is the maximum pressure value, G is the weight of the cutting tool 30, S is the sum of the cross-sectional areas of the left and right specimens, and τ is the shear strength of the specimen.

[0073] The shear strength test device and test method of the above-mentioned composite plate take into account the deadweight of the mold. The sample is clamped by the centering mechanism 50 and the clamping mechanism 40 on the left and right sides respectively. It is easy to operate and can achieve automatic centering and symmetrical arrangement. The test efficiency is high and the repeatability is good. There is a recovery groove 13 on the base 10, which is convenient for observation during testing and has a wide range of test thickness. In addition, the downward pressure force is vertically centered, which improves the accuracy of the shear strength experiment. The test method uses shear samples clamped on both sides and up and down, which greatly reduces the requirements for sample processing.

[0074] The present invention is further described in detail below through specific embodiments.

[0075] Example 1

[0076] This embodiment tests the shear performance of a 40 mm 7B52-T6 composite plate 1. The 7B52 composite plate 1 is mainly composed of 7A52 and 7A62 aluminum alloy materials, wherein the thickness of the 7A52 layer is 4.2 mm, and the thickness of the 7A62 layer is 36.8 mm.

[0077] The outer dimensions of the base 10 are 115mm×60mm×75mm in length, width and height, and are symmetrical. The tool groove 12 on the base 10 is 15mm wide, and the dimensions of the mold cavity 11 are 65mm×60mm×30mm in length, width and height. The bolt groove on the base 10 is 20mm wide and 15mm deep. The dimensions of the sample recovery groove 13 are 15mm wide and 10mm deep. The nut is 10mm high and 14.8mm in diameter, and there is a No. 8 hexagonal hole on the nut; the bolt is 24mm long and 10mm in diameter.

[0078] The cutting tool 30 is in the shape of a rectangular parallelepiped structure, with a length, width and height of 60 mm×14.95 mm×80 mm and a weight of 5.6N.

[0079] The fixed mold 20 has an overall dimension of 65mm×60mm×30mm in length, width and height, a lower plate thickness of 3mm, a clamping piece 44 thickness of 4mm, a side body thickness of 8mm, an upper plate thickness of 15mm, and an upper plate with a countersink of 13mm in diameter and 10mm in depth. The clamping screw 42 has a length of 16mm and a diameter of 8mm, a cap head of the clamping screw 42 has a diameter of 10mm and a height of 5mm, and a No. 6 hexagonal countersink is provided on the cap head.

[0080] The 7B52 composite board 1 was cut into a sample with a length×width×thickness of 20 mm×7 mm×4 mm by wire cutting, and polished with 400 mesh, 800 mesh, and 1500 mesh sandpaper until the layer interface 2 of 7A52 and 7A62 could be cleaned and seen, and then the sample was cut into two test samples with a size of 10 mm×7 mm×4 mm by wire cutting.

[0081] Two samples to be tested are placed on the fixed mold 20, with the interface 2 flush with the jaws, and are initially fixed using the centering mechanism 50, and then the clamping screw 42 is tightened with a No. 6 hexagon socket to lock the samples to be tested.

[0082] The fixed mold 20 with two samples to be tested is placed in the mold cavity 11 on the base 10, and the tightening bolts on the base 10 are tightened with a No. 8 hexagon socket.

[0083] The cutting tool 30 is placed in the cutting tool slot 12 of the base 10 .

[0084] Place the assembled test device on a universal testing machine, set the testing machine to compression mode, press the cutting tool downward by 30 degrees, and the pressing speed is 1 mm / min. The test is carried out until the interface 2 is destroyed. Figure 8 As shown, read the maximum pressure F max =5834.4N.

[0085] According to the formula The shear strength of the specimen was calculated.

[0086] Example 2

[0087] The same testing device as in Example 1 is used to test the shear properties of a 4.5 mm thick 7A52 / 7A62 hot-rolled composite plate 1 material, wherein the thickness of the 7A52 layer is 2 mm and the thickness of the 7A62 layer is 2.5 mm.

[0088] The 7A52 / 7A62 hot-rolled composite plate 1 was cut into a sample with a length×width×thickness of 20 mm×4 mm×4 mm by wire cutting, and polished with 400 mesh, 800 mesh, and 1500 mesh sandpaper until the layer interface 2 of 7A52 and 7A62 could be cleaned and seen, and then the sample was cut into two test samples of 10 mm×4 mm×4 mm by wire cutting.

[0089] Two samples to be tested are placed on the fixed mold 20, with the interface 2 flush with the jaws, and are initially fixed using the centering mechanism 50, and then the clamping screw 42 is tightened with a No. 6 hexagon socket to lock the samples to be tested.

[0090] The fixed mold 20 with two samples to be tested is placed in the mold cavity 11 on the base 10, and the tightening bolts on the base 10 are tightened with a No. 8 hexagon socket.

[0091] The cutting tool 30 is placed in the cutting tool slot 12 of the base 10 .

[0092] Place the assembled test device on a universal testing machine, set the testing machine to compression mode, press the cutting tool downward by 30 at a speed of 1.5 mm / min, and conduct the test until the interface 2 is destroyed. Figure 8 As shown, read the maximum pressure F max =5059.8N.

[0093] According to the formula

[0094] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

Claims

1. A shear strength test device for a composite plate, characterized in that: include: A base, wherein the base is provided with a mold cavity and a cutting tool groove, the cutting tool groove is communicated with the mold cavity, and the base is also provided with an operation port communicated with the mold cavity; A fixed mold is installed in the mold cavity through the operation port, the fixed mold is provided with a cutting tool channel connected to the cutting tool groove, and two groups of clamping mechanisms for clamping the composite board are provided in the fixed mold, and the two groups of clamping mechanisms are respectively arranged on both sides of the cutting tool channel; and The cutting tool is slidably disposed in the cutting tool groove, and the cutting tool can press down the composite plate through the cutting tool channel.

2. The shear strength testing device for composite panels according to claim 1, characterized in that: It also includes a fixing piece, which is arranged on the base and connected to the fixed mold to fix the fixed mold in the mold cavity.

3. The shear strength testing device for composite panels according to claim 1, characterized in that: The cutting tool has a pressing end and a connecting end opposite to each other, wherein the pressing end is used for pressing down the composite plate, and the connecting end is used for connecting to a universal testing machine.

4. The shear strength testing device for composite panels according to claim 1, characterized in that: The clamping mechanism includes a clamping screw and a clip. The clamping screw is rotatably mounted on the fixed mold. The head of the clamping screw passes through the fixed mold and is exposed to the outside. The clip is threadedly mounted on the clamping screw. The fixed mold is provided with a clamping surface that cooperates with the clip to clamp the composite board.

5. The shear strength testing device for composite panels according to claim 1, characterized in that: The fixed mold is also provided with two sets of centering mechanisms, which are respectively arranged on both sides of the cutting tool channel, and the centering mechanisms are used to preliminarily fix the composite plate.

6. The shear strength testing device for composite panels according to claim 5, characterized in that: The centering mechanism includes a centering screw and two positioning plates. The centering screw is rotatably installed on the fixed mold. The centering screw is provided with two threaded sections with opposite rotation directions. The two positioning plates are respectively threadedly installed on the two threaded sections.

7. The shear strength testing device for composite panels according to claim 6, characterized in that: The centering mechanism also includes a linkage assembly. One of the centering screws in the two sets of centering mechanisms is an active screw, and the other centering screw is a driven screw. The linkage assembly is used to drive the driven screw to rotate by rotating the active screw.

8. The shear strength testing device for composite panels according to claim 7, characterized in that: The linkage assembly includes a linkage shaft, a first helical gear set and a second helical gear set. One end of the linkage shaft is transmission-connected to the active screw through the first helical gear set, and the other end of the linkage shaft is transmission-connected to the driven screw through the second helical gear set.

9. A method for testing the shear strength of a composite plate, using the shear strength testing device for a composite plate as claimed in any one of claims 1 to 8, characterized in that: The following steps are involved: Process the composite plate and grind it until the interface can be observed; Two clamping mechanisms are used to clamp and fix the two composite plates in a fixed mold respectively, and the interface of the composite plate is flush with the jaws of the cutting tool channel; Installing the fixed mold equipped with the composite board into the mold cavity through the operation port; Installing the cutting tool into the cutting tool slot and connecting the cutting tool to the universal testing machine; Starting the universal testing machine, pressing the cutting tool downward, the cutting tool pressing the composite plate downward through the cutting tool channel, and reading the maximum pressure value; The shear strength of the composite plate is calculated based on the obtained maximum pressure value.

10. The shear strength testing method of a composite board according to claim 9, characterized in that: The step of calculating the shear strength of the composite plate according to the obtained maximum pressure value is specifically as follows: The shear strength of the composite plate is calculated according to the sum of the maximum pressure value, the weight of the cutting tool and the cross-sectional area of ​​the composite plate.

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