Fixture and method for testing tensile shear creep of adhesives by cross method

Abstract

The present invention discloses a fixture and method for testing the tensile shear creep of adhesives by a cross method, and belongs to the field of adhesive shear creep testing. The present invention uses a U-shaped first clamping plate with two J-shaped hook grooves at one end, and a rectangular second clamping plate with a J-shaped hook groove at one end to form a fixture, and effectively fixes the cross-cross specimen in the fixture. The present invention can fix the cross-cross specimen, use tensile load to perform shear creep testing, eliminate the rotation of the test piece caused by the traction of the adhesive layer, so as to more accurately measure the shear creep performance of the adhesive, and can be applied to test pieces with different adhesive layer thicknesses, without the need to prepare fixtures of different specifications, thereby reducing the test cost and improving the test efficiency.

Description

Technical Field

[0001] The invention relates to the field of adhesive shear creep testing, in particular to a fixture and a method for testing adhesive tensile shear creep using a cross method. Background Art

[0002] Adhesives are widely used in the connection between various materials and components. Due to the long service life and continuous stress, adhesives will inevitably creep. Therefore, it is necessary to test and characterize the creep performance of adhesives. The current Chinese national standard "GB / T 7750-1987 Adhesive Tensile Shear Creep Test Method (Metal to Metal)" discloses a test method for adhesive tensile shear creep. The test specimen is as follows: Figure 1 As shown. This method is only applicable to cases where the bonding layer is thin. For silicone weathering adhesives, silicone structural sealants, and other adhesives that require a certain thickness when used, this method cannot accurately measure their shear creep properties. On the other hand, this method requires drilling connection holes on the test piece, which is only applicable to metal material specimens. For brittle materials such as ceramics and glass, drilling can easily damage the test piece, resulting in unnecessary waste and reduced test efficiency.

[0003] Chinese patent document CN1512161A discloses a method for testing the shear strength of a solid material bonding interface. This method can perform shear creep testing of materials by compressing loads, such as Figure 2 As shown. Two strips of the shaped substrate are glued into a vertical cross test piece with the adhesive to be tested. During the test, the horizontal substrate is placed on the support, the upper part of the vertical substrate is subjected to a vertical downward pressure load, and the lower part can be connected to a displacement sensor (such as a micrometer) to collect creep displacement. However, the disadvantage of this test method is that since the supporting force and the downward pressure load are not on the same line, the tested piece will tend to rotate in the direction of the vertical substrate, thereby causing errors. This phenomenon is more obvious when the adhesive layer is thicker. On the other hand, this method can only be tested by downward pressure load, and shear creep test cannot be performed using tensile load. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a fixture and method for testing the tensile shear creep of an adhesive using the cross method. The present invention can fix the cross specimen and perform a shear creep test using a tensile load, thereby eliminating the rotation of the test piece caused by the traction of the adhesive layer, thereby more accurately measuring the shear creep performance of the adhesive. The present invention can be applied to test pieces with different adhesive layer thicknesses, and there is no need to prepare fixtures of different specifications, thereby reducing the test cost and improving the test efficiency.

[0005] The present invention provides the following technical solutions:

[0006] A fixture for testing the tensile shear creep of an adhesive by a cross method, the fixture comprising a first clamping plate and a second clamping plate, wherein:

[0007] The first clamping plate comprises a first connecting portion, on which a first connecting structure for connecting to a tensile instrument is arranged, on which two rectangular first clamping portions which are parallel to each other and spaced a certain distance apart are fixedly arranged, the first connecting portion and the two first clamping portions form a U-shaped structure, and at the end of each first clamping portion a first J-shaped hook groove for clamping a transverse substrate in a cross-crossed specimen is arranged;

[0008] The second clamping plate is rectangular in shape, one end of the second clamping plate is a second connecting portion, the second connecting portion is provided with a second connecting structure for connecting to a tensile instrument, the other end of the second clamping plate is a second clamping portion, and the end of the second clamping portion is provided with a second J-shaped hook groove for clamping a vertical substrate in a cross specimen.

[0009] Furthermore, the second connecting portion is bent a certain distance relative to the second clamping portion toward the side where the second J-shaped hook groove is located.

[0010] Furthermore, a first threaded hole is formed at the end of the first clamping portion at the first J-shaped hook groove, and a second threaded hole is formed at the end of the second clamping portion at the second J-shaped hook groove, and both the first threaded hole and the second threaded hole are equipped with screws.

[0011] Furthermore, the first connection structure is a first pin hole provided on the first connection portion, and the second connection structure is a second pin hole provided on the second connection portion.

[0012] Furthermore, the first connecting portion and the two first clamping portions are an integral structure.

[0013] Further, the length of the first connecting portion is 24 mm, the width is 70 mm, the height is 3.5 mm, the diameter of the first pin hole is 7.5 mm, the center of the first pin hole is located on the center line of the width direction of the first clamping plate, and the distance between the center of the first pin hole and the outer long side of the first connecting portion is 8.75 mm;

[0014] The length of the first clamping portion is 96 mm, the width is 24 mm, and the height is 2 mm. The length of the groove space formed by the first J-shaped hook groove is 15 mm, the width is 24 mm, and the height is 4 mm. The two first clamping portions are symmetrical about the lengthwise center line of the first connecting portion, and the distance between the two first clamping portions is 22 mm.

[0015] The diameter of the first threaded hole is 3 mm, the center of the first threaded hole is located on the center line of the width direction of the first clamping part, and the distance between the center of the first threaded hole and the outer short side of the first clamping part is 5 mm.

[0016] Further, the length of the second connecting portion is 57 mm, the width is 15 mm, the height is 3.5 mm, the diameter of the second pin hole is 7.5 mm, the center of the second pin hole is located on the center line of the width direction of the second connecting portion, and the distance between the center of the second pin hole and the outer short side of the second connecting portion is 8.75 mm;

[0017] The second clamping portion has a length of 63 mm, a width of 15 mm, and a height of 2 mm, and the groove space formed by the second J-shaped hook groove has a length of 10 mm, a width of 15 mm, and a height of 4 mm;

[0018] The second connecting portion is bent 90 degrees relative to the second clamping portion toward the side where the second J-shaped hook groove is located, the height of the inner bending angle formed by the bending is 6.5 mm, and the height of the outer bending angle formed by the bending is 5 mm;

[0019] The diameter of the second threaded hole is 3 mm, the center of the second threaded hole is located on the center line of the width direction of the second clamping part, and the distance between the center of the second threaded hole and the outer short side of the second clamping part is 5 mm.

[0020] A method for performing a tensile shear creep test on an adhesive using the aforementioned fixture, the method comprising:

[0021] S1: Measure the bonding interface area S of the adhesive in the cross specimen and the length dimension X of the adhesive in the direction of tensile load;

[0022] S2: Connect the first connection structure of the first clamping plate to the upper connection mechanism of the tensile instrument, embed the transverse substrate in the cross sample into the first J-shaped hook groove, and make the adhesive layer in the cross sample pass through the gap between the two first connection parts;

[0023] S3: The second clamping plate is arranged opposite to the first clamping plate, and the vertical substrate in the cross specimen is embedded in the second J-shaped hook groove, and the second connecting structure of the second clamping plate is connected to the lower connecting mechanism of the tensile instrument;

[0024] S4: Start the tensile instrument so that the upper connecting mechanism and the lower connecting mechanism of the tensile instrument are separated from each other, and apply a tensile load F to the cross specimen;

[0025] S5: Maintain the tensile load F for a period of time, record the deformation of the adhesive in the tensile direction over time ΔX(t), and calculate the tensile shear creep compliance J(t) of the adhesive using the following formula:

[0026]

[0027] Furthermore, the S2 further comprises: tightening a screw in the first threaded hole to press the transverse substrate against the inner wall of the first J-shaped hook groove;

[0028] The step S3 further includes: tightening a screw in the second threaded hole to press the vertical substrate against the inner wall of the second J-shaped hook groove.

[0029] The present invention has the following beneficial effects:

[0030] The present invention uses a U-shaped first clamping plate with two J-shaped hook grooves at one end and a rectangular second clamping plate with a J-shaped hook groove at one end to form a clamp, which effectively fixes the cross-cross specimen in the clamp, can use tensile load to perform shear creep test, and avoids the possibility of rotation of the test piece, reducing the error in the test process. In addition, the present invention can clamp cross-cross specimens of different materials and different adhesive layer thicknesses without making or replacing clamps of different specifications, saving test costs and improving test efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic diagram of the adhesive tensile shear creep test specimen disclosed in the Chinese national standard GB / T 7750-1987;

[0032] Figure 2 It is a schematic diagram of the cross shear strength test method disclosed in Chinese patent document CN1512161A;

[0033] Figure 3 A schematic diagram of an embodiment of a first clamping plate of a fixture for testing the tensile shear creep of an adhesive using the cross method of the present invention;

[0034] Figure 4 A schematic diagram of an embodiment of a second clamping plate of a fixture for testing the tensile shear creep of an adhesive using the cross method of the present invention;

[0035] Figure 5 It is a schematic diagram of the cross specimen;

[0036] Figure 6 A schematic diagram of another embodiment of the first clamping plate of the clamp for testing the tensile shear creep of adhesives by the cross method of the present invention;

[0037] Figure 7A schematic diagram of another embodiment of the second clamping plate of the fixture for testing the tensile shear creep of adhesives by the cross method of the present invention;

[0038] Figure 8 is a schematic diagram of the connection between the first clamping plate and the tension instrument;

[0039] Fig. 9 A front view of a tensile shear creep test of an adhesive using the fixture of the present invention;

[0040] Fig.10 It is a stereoscopic diagram of using the fixture of the present invention to perform adhesive tensile shear creep test. DETAILED DESCRIPTION

[0041] In order to make the technical problems, technical solutions and advantages to be solved by the present invention more clear, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0042] Embodiment 1:

[0043] An embodiment of the present invention provides a fixture for testing the tensile shear creep of an adhesive using the cross method. The fixture is used in conjunction with an instrument that can provide tension to clamp and fix a cross specimen when testing the tensile shear creep compliance of an adhesive.

[0044] like Figure 5 As shown, the cross sample 100 includes two bonded substrates and an adhesive arranged crosswise. Figure 5 Taking the direction shown as a reference, the two bonded substrates are a horizontal substrate 200 and a vertical substrate 300, respectively. The horizontal substrate 200 and the vertical substrate 300 are vertically bonded by an adhesive 400. The sizes of the horizontal substrate 200 and the vertical substrate 300 can be the same or different, and their materials can be the same or different. The materials can be rigid solids such as metal, ceramic, glass, plastic, and wood.

[0045] like Figure 3 , 4 As shown, the clamp comprises a first clamping plate 1 and a second clamping plate 2, wherein:

[0046] The overall shape of the first clamping plate is a U-shaped plate with two J-shaped hook grooves at one end: the first clamping plate 1 includes a first connecting portion 11, on which a first connecting structure 12 for connecting to a tensile instrument is provided, and on which two rectangular first clamping portions 13 parallel to each other and spaced a certain distance apart are fixedly provided, the first connecting portion 11 and the two first clamping portions 13 form a U-shaped structure, and at the end of each first clamping portion 13 a first J-shaped hook groove 14 for clamping the transverse substrate 200 in the cross specimen 100 is provided.

[0047] The overall shape of the second clamping plate is a rectangular plate with a J-shaped hook groove at one end: the second clamping plate 2 is in the shape of a rectangle, one end of the second clamping plate 2 is a second connecting portion 21, and the second connecting portion 21 is provided with a second connecting structure 22 for connecting to a tensile instrument, and the other end of the second clamping plate 2 is a second clamping portion 23, and the end of the second clamping portion 23 is provided with a second J-shaped hook groove 24 for clamping the vertical substrate 400 in the cross specimen 100.

[0048] The use process of the present invention is as follows:

[0049] Connect the first connection structure of the first clamping plate to the upper connection mechanism of the tension instrument, such as Figure 8 The horizontal substrate in the cross sample is embedded in the first J-shaped hook groove, and the adhesive layer in the cross sample passes through the gap between the two first connecting parts, as shown. Fig. 9 , 10 shown.

[0050] Then, the second clamping plate is arranged opposite to the first clamping plate, and the vertical substrate in the cross sample is embedded in the second J-shaped hook groove, and the second connecting structure of the second clamping plate is connected to the lower connecting mechanism of the tensile instrument, such as Fig. 9 , 10 shown.

[0051] Start the tensile instrument so that the upper connecting mechanism and the lower connecting mechanism of the tensile instrument are separated from each other, apply a tensile load to the cross specimen, and record the deformation of the adhesive in the tensile direction over time.

[0052] The tensile shear creep compliance of the adhesive can be calculated based on the adhesive size, applied load and deformation.

[0053] The present invention uses a U-shaped first clamping plate with two J-shaped hook grooves at one end and a rectangular second clamping plate with a J-shaped hook groove at one end to form a clamp, which effectively fixes the cross-cross specimen in the clamp, can use tensile load to perform shear creep test, and avoids the possibility of rotation of the test piece, reducing the error in the test process. In addition, the present invention can clamp cross-cross specimens of different materials and different adhesive layer thicknesses without making or replacing clamps of different specifications, saving test costs and improving test efficiency.

[0054] As an improvement of the present invention, the second connecting portion 21 of the second clamping plate is bent by a certain distance relative to the second clamping portion 22 toward the side where the second J-shaped hook groove 24 is located.

[0055] like Figure 4As shown, the middle of the second clamping plate has a section bent perpendicular to the length direction, which is suitable for the case where the adhesive of the test piece is thicker. The upper and lower connecting rods of tensile testing machines and other tensile instruments are generally located on a straight line in the vertical direction. The return bend of the second clamping plate can correct the horizontal position deviation of the two bonded substrates caused by the thickness of the adhesive layer, making it easier for the two clamping plates to be connected to the tensile instrument.

[0056] As another improvement of the present invention, Figure 6 , 7 As shown, the first clamping portion 13 has a first threaded hole 15 at its end located at the first J-shaped hook groove 14, and the second clamping portion 23 has a second threaded hole 25 at its end located at the second J-shaped hook groove 24. Both the first threaded hole 15 and the second threaded hole 25 are equipped with screws.

[0057] The J-shaped hook groove ends of the two clamping plates are both provided with threaded holes for use with screws. The screws can be screwed into the hook grooves to press the bonded substrates against the inner wall of the hook grooves, thereby fixing the bonded substrate test pieces of different thicknesses and sizes and improving the effect of preventing the test pieces from rotating. On the other hand, even if the bonding layer is damaged during the test and the cross-cross specimen is broken, the bonded substrates are still pressed in the hook grooves by the screws and will not fall off, thus avoiding damage to the bonded substrates.

[0058] In the present invention, the first connection part and the second connection part connected to the tensile instrument can be of various structures, such as being clamped on the tensile machine in a plate shape, being connected to the tensile machine with threads, etc. Preferably, the first connection structure 12 is a first pin hole opened on the first connection part 11, and the second connection mechanism 22 is a second pin hole opened on the second connection part 21.

[0059] like Figure 3 , 4 As shown in , 6 and 7, the first connecting part and the second connecting part are thin plates with pin holes. The thickness of the thin plates and the size of the pin holes are matched with the tensile machine. The thin plates are inserted into the slits of the connecting rods of the tensile machine and fixed by the positioning pins 3 passing through the pin holes. Figure 8 shown.

[0060] The dimensions of the present invention can be determined according to the dimensions of the cross-section specimen to be tested and the tensile machine used for testing. In order to unify the references in all directions, the length, width and height directions are defined as Figure 3 In the direction shown in the figure, the length, width and height directions of all parts in the present invention are the same as Figure 3 The length, width, and height defined in are in the same direction.

[0061] It should be ensured that: the size of the first / second connecting part matches the tensile testing machine and can be tightly connected thereto; the length of the first / second clamping plate is sufficient to accommodate the cross-cross specimen to be tested and leave enough margin so that the adhesive can be fully deformed during the test, and the second clamping plate will not contact the horizontally placed lateral substrate; the height of the first / second J-shaped hook groove is greater than the thickness of the bonded substrate, so that the bonded substrate can be smoothly placed in the first / second J-shaped hook groove; the gap between the two hook grooves of the first clamping plate is large enough to allow the adhesive layer to pass through without contacting the first clamping plate to generate friction; the length of the first / second J-shaped hook groove is long enough to allow the bonded substrate to be tightly attached to the inner wall of the first / second J-shaped hook groove and have a certain contact area so that the bonded substrate does not rotate.

[0062] Preferably, the first connecting portion 11 of the first clamping plate and the two first clamping portions 13 are an integral structure.

[0063] The first clamping plate is a rectangular thin plate with a length of 120 mm and a width of 70 mm, and a rectangular through hole with a length of 96 mm and a width of 22 mm is opened in the middle. The through hole is symmetrical about the central axis of the first clamping plate.

[0064] The first connecting part has a length of 24 mm, a width of 70 mm, and a height of 3.5 mm, with a first pin hole in the middle. The diameter of the first pin hole is 7.5 mm, the center of the first pin hole is located on the center line of the width direction of the first clamping plate, and the distance between the center of the first pin hole and the outer long side of the first connecting part is 8.75 mm.

[0065] There is a first clamping part of a rectangular thin plate along each of the two long sides of the first clamping plate. The length of the first clamping part is 96mm, the width is 24mm, and the height is 2mm. The first clamping plate is bent 90° twice at the end to form a first J-shaped hook groove. The groove space formed by the first J-shaped hook groove has a length of 15mm, a width of 24mm, and a height of 4mm. The two first clamping parts are symmetrical about the center line of the length direction of the first connecting part, and the spacing between the two first clamping parts is 22mm.

[0066] A first threaded hole is opened on each of the two first clamping plates. The diameter of the first threaded hole is 3 mm. The center of the first threaded hole is located on the center line of the width direction of the first clamping part, and the distance between the center of the first threaded hole and the outer short side of the first clamping part is 5 mm.

[0067] The second clamping plate is a rectangular thin plate with a length of 120 mm and a width of 15 mm. The second connecting part has a length of 57 mm, a width of 15 mm, and a height of 3.5 mm. A second pin hole is opened in the middle. The diameter of the second pin hole is 7.5 mm. The center of the second pin hole is located on the center line of the second connecting part in the width direction, and the distance between the center of the second pin hole and the outer short side of the second connecting part is 8.75 mm.

[0068] The second clamping portion has a length of 63 mm, a width of 15 mm and a height of 2 mm. The second clamping plate is bent 90° twice at the end to form a second J-shaped hook groove. The groove space formed by the second J-shaped hook groove has a length of 10 mm, a width of 15 mm and a height of 4 mm.

[0069] The second connecting portion is bent 90 degrees relative to the second clamping portion toward the side where the second J-shaped hook groove is located. The height of the inner bending angle formed by the bending (i.e. the height of the upper edge formed after bending at the bending point) is 6.5mm, the height of the outer bending angle formed by the bending (i.e. the height of the lower edge formed after bending at the bending point) is 5mm, and the height of the second clamping portion at the bending point is 2mm.

[0070] A second threaded hole is opened on the second clamping plate, the diameter of the second threaded hole is 3mm, the center of the second threaded hole is located on the center line of the width direction of the second clamping part, and the distance between the center of the second threaded hole and the outer short side of the second clamping part is 5mm.

[0071] Embodiment 2:

[0072] The embodiment of the present invention provides a method for performing a tensile shear creep test on an adhesive using the fixture of embodiment 1, the method comprising:

[0073] S1: Measure the bonding interface area S of the adhesive in the cross specimen and the length dimension X of the adhesive in the direction to be subjected to the tensile load.

[0074] S is the bonding interface area between the bonded substrate and the adhesive, and X is the length of the adhesive in the direction to be subjected to the tensile load. S and X can be measured by a steel ruler or a vernier caliper.

[0075] S2: Connect the first connection structure of the first clamping plate to the upper connection mechanism of the tensile instrument, embed the transverse substrate in the cross sample into the first J-shaped hook groove, and make the adhesive layer in the cross sample pass through the gap between the two first connection parts, such as Fig. 9 , 10 shown.

[0076] S3: The second clamping plate is arranged opposite to the first clamping plate, and the vertical substrate in the cross sample is embedded in the second J-shaped hook groove to fix the cross sample, and the second connecting structure of the second clamping plate is connected to the lower connecting mechanism of the tensile instrument, such as Fig. 9 , 10 shown.

[0077] S4: Start the tensile instrument so that the upper connecting mechanism and the lower connecting mechanism of the tensile instrument are separated from each other, and apply a tensile load F to the cross specimen.

[0078] The tensile instrument is preferably a tensile machine, and the upper connecting mechanism and the lower connecting mechanism of the tensile machine are connecting rods. The loading load can be set by a computer, or a weight load can be applied to make the upper and lower connecting rods of the tensile machine move away from each other in the vertical direction, thereby generating a tensile load F on the test piece, causing shear deformation of the adhesive layer.

[0079] S5: Maintain the tensile load F for a period of time, record the deformation of the adhesive in the tensile direction over time ΔX(t), and calculate the tensile shear creep compliance J(t) of the adhesive using the following formula:

[0080]

[0081] In the above formula:

[0082] J(t) is the shear creep compliance of the adhesive, in MPa -1 ;

[0083] X is the length of the adhesive in the stretching direction, in mm;

[0084] ΔX(t) is the deformation of the adhesive in the tensile direction, in mm;

[0085] F is the vertical load applied by the tensile machine on the test piece, in N;

[0086] S is the area of ​​the bonding interface between the bonded substrate and the adhesive, in mm 2 .

[0087] If the first / second clamping plate is provided with a first / second threaded hole and a screw, S2 further includes: tightening the screw in the first threaded hole to press the transverse substrate against the inner wall of the first J-shaped hook groove to accommodate specimens of different sizes.

[0088] Similarly, S3 also includes: tightening the screw in the second threaded hole to press the vertical substrate against the inner wall of the second J-shaped hook groove to accommodate samples of different sizes.

[0089] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A fixture for testing the tensile shear creep of adhesives by the cross method, characterized in that: The clamp comprises a first clamping plate and a second clamping plate, wherein: The first clamping plate comprises a first connecting portion, on which a first connecting structure for connecting to a tensile instrument is arranged, on which two rectangular first clamping portions which are parallel to each other and spaced a certain distance apart are fixedly arranged, the first connecting portion and the two first clamping portions form a U-shaped structure, and at the end of each first clamping portion a first J-shaped hook groove for clamping a transverse substrate in a cross-crossed specimen is arranged; The second clamping plate is rectangular in shape, one end of the second clamping plate is a second connecting portion, the second connecting portion is provided with a second connecting structure for connecting with a tensile instrument, the other end of the second clamping plate is a second clamping portion, the end of the second clamping portion is provided with a second J-shaped hook groove for clamping a vertical substrate in a cross-crossed specimen; The second connecting portion is bent relative to the second clamping portion toward the side where the second J-shaped hook groove is located for a certain distance; A first threaded hole is formed at the end of the first clamping portion at the first J-shaped hook groove, and a second threaded hole is formed at the end of the second clamping portion at the second J-shaped hook groove. Both the first threaded hole and the second threaded hole are equipped with screws.

2. The fixture for testing the tensile shear creep of adhesives by the cross method according to claim 1 is characterized in that: The first connection structure is a first pin hole formed on the first connection portion, and the second connection structure is a second pin hole formed on the second connection portion.

3. The fixture for testing the tensile shear creep of adhesives by the cross method according to claim 2, characterized in that: The first connecting portion and the two first clamping portions are an integral structure.

4. The fixture for testing the tensile shear creep of adhesives by the cross method according to claim 3 is characterized in that: The length of the first connecting portion is 24 mm, the width is 70 mm, the height is 3.5 mm, the diameter of the first pin hole is 7.5 mm, the center of the first pin hole is located on the center line of the width direction of the first clamping plate, and the distance between the center of the first pin hole and the outer long side of the first connecting portion is 8.75 mm; The length of the first clamping portion is 96 mm, the width is 24 mm, and the height is 2 mm. The length of the groove space formed by the first J-shaped hook groove is 15 mm, the width is 24 mm, and the height is 4 mm. The two first clamping portions are symmetrical about the lengthwise center line of the first connecting portion, and the distance between the two first clamping portions is 22 mm. The diameter of the first threaded hole is 3 mm, the center of the first threaded hole is located on the center line of the width direction of the first clamping part, and the distance between the center of the first threaded hole and the outer short side of the first clamping part is 5 mm.

5. The fixture for testing the tensile shear creep of adhesives by the cross method according to claim 4, characterized in that: The second connecting portion has a length of 57 mm, a width of 15 mm, and a height of 3.5 mm. The diameter of the second pin hole is 7.5 mm. The center of the second pin hole is located on the center line of the width direction of the second connecting portion, and the distance between the center of the second pin hole and the outer short side of the second connecting portion is 8.75 mm. The second clamping portion has a length of 63 mm, a width of 15 mm, and a height of 2 mm, and the groove space formed by the second J-shaped hook groove has a length of 10 mm, a width of 15 mm, and a height of 4 mm; The second connecting portion is bent 90 degrees relative to the second clamping portion toward the side where the second J-shaped hook groove is located, the height of the inner bending angle formed by the bending is 6.5 mm, and the height of the outer bending angle formed by the bending is 5 mm; The diameter of the second threaded hole is 3 mm, the center of the second threaded hole is located on the center line of the width direction of the second clamping part, and the distance between the center of the second threaded hole and the outer short side of the second clamping part is 5 mm.

6. A method for performing adhesive tensile shear creep testing using the fixture described in any one of claims 1 to 5, characterized in that: The method comprises: S1: Measure the bonding interface area S of the adhesive in the cross specimen and the length dimension X of the adhesive in the direction of tensile load; S2: Connect the first connection structure of the first clamping plate to the upper connection mechanism of the tensile instrument, embed the transverse substrate in the cross sample into the first J-shaped hook groove, and make the adhesive layer in the cross sample pass through the gap between the two first connection parts; S3: The second clamping plate is arranged opposite to the first clamping plate, and the vertical substrate in the cross specimen is embedded in the second J-shaped hook groove, and the second connecting structure of the second clamping plate is connected to the lower connecting mechanism of the tensile instrument; S4: Start the tensile instrument so that the upper connecting mechanism and the lower connecting mechanism of the tensile instrument are separated from each other, and apply a tensile load F to the cross specimen; S5: Maintain the tensile load F for a period of time, record the deformation of the adhesive in the tensile direction over time ΔX(t), and calculate the tensile shear creep compliance J(t) of the adhesive using the following formula:

7. The method according to claim 6, characterized in that The S2 further includes: tightening a screw in the first threaded hole to press the transverse substrate against the inner wall of the first J-shaped hook groove; The step S3 further includes: tightening a screw in the second threaded hole to press the vertical substrate against the inner wall of the second J-shaped hook groove.

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