Nested self-adaptive adjustment loading device and method for sheet glass tensile strength test

Abstract

The invention discloses a nested self-adaptive adjustment loading device and method for sheet glass tensile strength testing, and belongs to the technical field of glass tensile strength tests.The device comprises an upper mounting mechanism and a lower mounting mechanism, the upper mounting mechanism and the lower mounting mechanism are connected through a sliding assembly, and the sliding assembly comprises parallel linear guide rails; the lower end of the parallel linear guide rail is fixed on the lower mounting mechanism, and the upper end is slidably connected with the upper mounting mechanism. According to the nested self-adaptive adjustment loading device and method for testing the tensile strength of the sheet glass, the design of double sliding rails is adopted, the upper clamp slides on the two parallel linear guide rails, left-right and in-plane relative displacement is further limited, the silica gel gaskets are adopted to prevent the glass from being in direct contact with the clamp, and the clamping efficiency is improved. When the contact surface of the clamp and glass is not smooth and possibly has stress concentration, the low-modulus silica gel gasket can provide a chance of self-adaption to the side surface of a groove of the clamp for a glass sample, and is suitable for different types of sheet-shaped glass samples.

Description

Technical Field

[0001] The invention relates to the technical field of glass tensile strength testing, in particular to a nested adaptive adjustment loading device and method for testing the tensile strength of sheet glass. Background Art

[0002] Inorganic silicate glass has been widely used in the fields of aviation, automobiles, electronics, etc., and its tensile strength directly affects the durability and safety of the material. Inorganic silicate glass is a brittle material, and its tensile strength is usually between 40MPa and 200MPa. The process conditions such as cooling rate and melting temperature during glass manufacturing have an important influence on the internal structure of the glass, thereby affecting the strength. In addition, heat-treated glass usually has higher strength. Inorganic silicate glass is prone to break under high stress or impact, so care must be taken when handling and installing it. As the flight requirements of aircraft continue to increase, accidents caused by stress damage to aviation glass during flight occur from time to time, such as the windshield breakage and detachment accident of Sichuan Airlines aircraft and various bird collision windshield accidents.

[0003] At present, there are no relevant specifications and standards for the tensile strength test of inorganic silicate glass. Although there are corresponding test standards for brittle materials such as high-performance ceramics, concrete and fiber-reinforced resin-based composites, including ASTM C1273, ASTM C307 and ASTM D3039, these standards are not applicable to inorganic silicate glass. ASTM C1273 and ASTM D3039 both use a clamping method to fix the specimen. This clamping device is prone to slip when the holding force is too small, and when the holding force is too large, it will induce local compressive stress concentration in the normal direction of the surface, causing the glass to fail prematurely at the clamping position. In addition, it is difficult to achieve precise centering of the upper and lower clamps, which may cause relative displacement from left to right and inside and outside the surface, thereby introducing additional shear loads and causing inaccurate tensile strength measurements. ASTM C307 uses an embedded method to fix the specimen, which effectively avoids premature failure caused by clamping stress concentration, but its 8-shaped specimen has extremely high processing accuracy requirements, otherwise stress concentration in the middle will occur, resulting in low measured tensile strength. In addition, since both the inorganic silicate glass and the fixture have relatively high stiffness, if the two are in direct contact and the glass edge is not processed smoothly enough, premature failure may occur at the loading end. Summary of the invention

[0004] The purpose of the present invention is to provide a nested adaptive adjustment loading device and method for testing the tensile strength of sheet glass. A double slide rail design is adopted, and two parallel linear guides are fixed on a lower clamp, so that the upper clamp slides on the two parallel linear guides, further limiting the left-right and inside-outside relative displacement. A silicone gasket is used to block the direct contact between the glass and the clamp. This design is used when the contact surface between the clamp and the glass is not very smooth and there may be stress concentration. The low-modulus silicone gasket can provide the glass sample with an opportunity to adapt to the side of the clamp groove, and is suitable for different types of glass samples. The samples of the test method can be repeatedly installed and disassembled without loss for many times, avoiding mechanical damage caused during the sample disassembly process.

[0005] To achieve the above-mentioned purpose, the present invention provides a nested adaptive adjustment loading device for testing the tensile strength of sheet glass, comprising an upper mounting mechanism and a lower mounting mechanism, wherein the upper mounting mechanism and the lower mounting mechanism are connected via a sliding assembly, wherein the sliding assembly comprises parallel linear guide rails, wherein the lower ends of the parallel linear guide rails are fixed to the lower mounting mechanism, and the upper ends of the parallel linear guide rails are slidably connected to the upper mounting mechanism.

[0006] Preferably, the upper mounting mechanism comprises an upper clamp, the upper portion of the upper clamp is fixedly connected to the upper universal joint, and the upper universal joint is fixedly connected to the first fixed mounting portion via a first fixing screw.

[0007] Preferably, the lower mounting mechanism includes a lower clamp, the lower portion of the lower clamp is fixedly connected to the lower universal joint, and the lower universal joint is fixedly connected to the second fixed mounting portion via a second fixing screw.

[0008] Preferably, a first mounting groove is opened in the middle of the upper clamp, an upper silicone gasket is fixed on the inner surface of the first mounting groove, an upper pressure head cover is provided at the first mounting groove, the upper pressure head cover is fixedly connected to the upper clamp by a first cover screw, and limited space is opened on the left and right sides of the first mounting groove respectively.

[0009] Preferably, a second mounting groove is opened in the middle of the lower clamp, a lower silicone gasket is fixed to the inner surface of the second mounting groove, a lower pressure head cover plate is provided at the second mounting groove, and the lower pressure head cover plate is fixedly connected to the lower clamp by a second cover plate screw.

[0010] Preferably, the number of the parallel linear guide rails is two, and the two parallel linear guide rails are placed in the two limiting spaces.

[0011] The present invention provides a nested adaptive adjustment loading method for testing the tensile strength of sheet glass, which uses the nested adaptive adjustment loading device for testing the tensile strength of sheet glass described above, and comprises the following steps:

[0012] S1. Prepare samples and make preliminary preparations;

[0013] S2. Insert the two parallel linear guide rails fixedly connected on the lower fixture into the two limit spaces of the upper fixture, further restrict the relative displacement of the upper and lower fixtures left and right and inside and outside the plane, so that the upper and lower fixtures and the sample remain vertical;

[0014] S3, fixing the upper silicone gasket and the lower silicone gasket in the first mounting groove and the second mounting groove respectively, blocking direct contact between the glass and the upper clamp and the lower clamp;

[0015] S4, place the sample into the first installation slot and the second installation slot, cover the first installation slot with an upper pressure head cover, and fix the upper pressure head cover to the upper fixture with a first cover screw, cover the second installation slot with a lower pressure head cover, and fix the lower pressure head cover to the lower fixture with a second cover screw;

[0016] S5. Clamp and fix the first fixed installation part and the second fixed installation part respectively by a universal testing machine, and make the whole device in a vertical direction by an upper universal joint and a lower universal joint, the upper universal joint is fixed by a first fixing screw, and the lower universal joint is fixed by a second fixing screw;

[0017] S6. Simulate the sample, rotate the sample around the x-axis, y-axis and z-axis by 0.5° or more to observe the fracture condition of the sample, and obtain the maximum angle between the two parallel linear guides through the fracture condition;

[0018] S7, the universal testing machine selects the displacement control mode, moves the first fixed installation part slowly upward at the set speed, observes the load-displacement curve on the testing machine software, and stops stretching when the load-displacement curve shows a load drop, and records the data;

[0019] S8. Remove the measured sample and replace it with a new sample to continue the test.

[0020] Preferably, the sample in S1 is a sheet of inorganic silicate glass with a thickness of 3 mm and an intermediate width of 3-6 mm. The test plane is the yz plane, the test direction is parallel to the length direction of the sheet glass, i.e., the z direction, the thickness direction is the y direction, and the width direction is the x direction.

[0021] Therefore, the present invention adopts the above-mentioned nested adaptive adjustment loading device and method for testing the tensile strength of sheet glass, adopts a double slide rail design, and two parallel linear guides are fixed on the lower clamp, so that the upper clamp slides on the two parallel linear guides, further limiting the left-right and inside-outside relative displacement, and using a silicone gasket to block the direct contact between the glass and the clamp. This design is used when the contact surface between the clamp and the glass is not very smooth and there may be stress concentration. The low-modulus silicone gasket can provide the glass sample with an opportunity to adapt to the side of the clamp groove, and is suitable for different types of sheet glass samples. The samples of the test method can be repeatedly installed and disassembled non-destructively for many times to avoid mechanical damage caused during the sample disassembly process.

[0022] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 2 is a front view of a device of an embodiment of a nested adaptive adjustment loading device and method for testing the tensile strength of sheet glass according to the present invention;

[0024] Figure 2 It is a schematic diagram of the sample structure of an embodiment of a nested adaptive adjustment loading device and method for testing the tensile strength of sheet glass of the present invention;

[0025] Figure 3 2. It is a schematic diagram of the three-dimensional structure of a device of an embodiment of a nested self-adaptive adjustment loading device and method for testing the tensile strength of sheet glass according to the present invention;

[0026] Figure 4 It is a stress cloud diagram of a sample of a nested adaptive adjustment loading device and method embodiment of a sheet glass tensile strength test according to the present invention when the sample is offset by 0.5° around the z-axis;

[0027] Figure 5 It is a stress cloud diagram of the embodiment of the nested adaptive adjustment loading device and method for testing the tensile strength of sheet glass of the present invention, with an angle of 0.5° formed by two parallel linear guide rails in the yz plane;

[0028] Figure 6 It is a load displacement curve diagram of the first embodiment of the nested adaptive adjustment loading device and method for testing the tensile strength of sheet glass of the present invention;

[0029] Figure 7 It is a tensile fracture diagram of Embodiment 1 of a nested adaptive adjustment loading device and method for testing the tensile strength of sheet glass of the present invention;

[0030] Figure 8 It is a load-displacement curve diagram of the sample rotated 0.5° around the z-axis in Example 2 of the nested adaptive adjustment loading device and method for testing the tensile strength of sheet glass of the present invention;

[0031] Fig. 9 This is a tensile fracture diagram of a sample rotated 0.5° around the z-axis in Example 2 of a nested adaptive adjustment loading device and method for testing the tensile strength of sheet glass of the present invention;

[0032] Fig.10 It is a load displacement curve diagram of the nested adaptive adjustment loading device and method for testing the tensile strength of sheet glass of the present invention after the sample is stretched with a copper gasket;

[0033] Fig.11 This is a tensile fracture diagram of a copper gasket for a sample in Example 3 of a nested adaptive adjustment loading device and method for testing the tensile strength of sheet glass of the present invention.

[0034] Reference numerals

[0035] 1. First fixed mounting part; 2. Upper universal joint; 3. First mounting groove; 4. Upper silicone gasket; 5. Upper pressure head cover; 6. First cover screw; 7. Parallel linear guide; 8. Limiting space; 9. Second fixed mounting part; 10. Lower universal joint; 11. Second mounting groove; 12. Lower silicone gasket; 13. Lower pressure head cover; 14. Second cover screw; 15. First fixing screw; 16. Second fixing screw; 17. Test specimen. DETAILED DESCRIPTION

[0036] The technical solution of the present invention is further described below through the accompanying drawings and embodiments.

[0037] Unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0038] like Figure 1-Figure 3As shown, the present invention provides a nested adaptive adjustment loading device for testing the tensile strength of sheet glass, comprising an upper mounting mechanism and a lower mounting mechanism, wherein the upper mounting mechanism and the lower mounting mechanism are used to clamp the sample 17. The upper mounting mechanism and the lower mounting mechanism are connected by a sliding assembly, and the sliding assembly is used to connect the upper mounting mechanism and the lower mounting mechanism, so that the upper mounting mechanism and the lower mounting mechanism can only slide up and down on the sliding assembly, further limiting the relative displacement of the upper mounting mechanism and the lower mounting mechanism left and right and inside and outside the surface.

[0039] The sliding assembly includes two parallel linear guide rails 7. The lower end of the parallel linear guide rail 7 is fixed on the lower mounting mechanism, and the upper end thereof is slidably connected to the upper mounting mechanism. A double slide rail design is adopted, and the upper clamp and the lower clamp can only slide up and down on the two parallel linear guide rails 7, further limiting the relative displacement left and right and inside and outside the surface. The two parallel linear guide rails 7 are fixed on the lower clamp, and the parallel linear guide rails 7 and the upper clamp can slide up and down relative to each other.

[0040] The upper mounting mechanism includes an upper fixture, the upper part of the upper fixture is fixedly connected to the upper universal joint 2, the upper universal joint 2 is fixedly connected to the first fixed mounting part 1 by a first fixing screw 15, and the first fixed mounting part 1 is connected to a universal testing machine, which can drive the first fixed mounting part 1 to move, thereby driving the upper fixture to move up and down. A first mounting groove 3 is provided in the middle of the upper fixture, and an upper silicone gasket 4 is fixed on the inner surface of the first mounting groove 3. The upper silicone gasket 4 is used to block the direct contact between the sample 17 and the upper fixture, and is used when the contact surface between the upper fixture and the glass is not very smooth and there may be stress concentration. The low-modulus upper silicone gasket 4 can provide the glass sample 17 with an opportunity to adapt to the side of the fixture groove. An upper pressure head cover 5 is provided at the first mounting groove 3, and the upper pressure head cover 5 is fixedly connected to the upper fixture by a first cover screw 6. The upper pressure head cover 5 is used to fix the sample 17 to prevent it from falling off, and to prevent the deflection angle in its yz plane from causing stress concentration. The first installation groove 3 has limited spaces 8 on both sides, and two parallel linear guide rails 7 are placed in the two limited spaces 8. The parallel linear guide rails 7 are used to limit the upper clamp and restrict the moving trajectory of the upper clamp.

[0041] The lower mounting mechanism includes a lower fixture, the lower part of the lower fixture is fixedly connected to the lower universal joint 10, the lower universal joint 10 is fixedly connected to the second fixed mounting part 9 by a second fixing screw 16, the second fixed mounting part 9 is connected to the universal testing machine, and the second fixed mounting part 9 is fixed under the action of the universal testing machine, thereby fixing the lower fixture. A second mounting groove 11 is provided in the middle of the lower fixture, and a lower silicone gasket 12 is fixed on the inner surface of the second mounting groove 11. The lower silicone gasket 12 is used to block the direct contact between the sample 17 and the lower fixture. When the contact surface between the lower fixture and the glass is not very smooth and there may be stress concentration, the low modulus lower silicone gasket 12 can provide the glass sample 17 with an opportunity to adapt to the side of the fixture groove. A lower pressure head cover 13 is provided at the second mounting groove 11, and the lower pressure head cover 13 is fixedly connected to the lower fixture by a second cover screw 14. The lower pressure head cover 13 is used to fix the sample 17 to prevent it from falling off, and to prevent the deflection angle in the yz plane from causing stress concentration.

[0042] The present invention provides a nested adaptive adjustment loading method for testing the tensile strength of sheet glass, which uses the nested adaptive adjustment loading device for testing the tensile strength of sheet glass, and comprises the following steps:

[0043] S1. Prepare sample 17 and make preliminary preparations: Sample 17 is a sheet of inorganic silicate glass with a thickness of 3 mm and a middle width of 3-6 mm. The test plane is the yz plane. The test direction is parallel to the length direction of the sheet glass, that is, the z direction. The thickness direction is the y direction and the width direction is the x direction.

[0044] S2. Insert the two parallel linear guide rails 7 fixedly connected on the lower fixture into the two limit spaces 8 of the upper fixture, so that the upper fixture can only slide on the two parallel linear rails, and further restrict the relative displacement of the upper fixture and the lower fixture left and right and inside and outside the plane, so that the upper fixture and the lower fixture and the sample 17 remain vertical;

[0045] S3. Fix the upper silicone gasket 4 and the lower silicone gasket 12 in the first mounting groove 3 and the second mounting groove 11 respectively to block the direct contact between the glass and the upper clamp and the lower clamp. This design is used when the contact surface between the upper clamp, the lower clamp and the glass is not very smooth and there may be stress concentration. The low modulus upper silicone gasket 4 and the lower silicone gasket 12 can provide the glass sample 17 with the opportunity to adapt to the side of the clamp groove.

[0046] S4. Place the sample 17 into the first mounting groove 3 and the second mounting groove 11, cover the first mounting groove 3 with the upper pressure head cover 5, and fix the upper pressure head cover 5 to the upper fixture by the first cover screw 6, cover the second mounting groove 11 with the lower pressure head cover 13, and fix the lower pressure head cover 13 to the lower fixture by the second cover screw 14, so as to fix the sample 17 to prevent it from falling off and to prevent the deviation in the yz plane from causing stress concentration.

[0047] S5. Clamp and fix the first fixed mounting part 1 and the second fixed mounting part 9 respectively by a universal testing machine, and make the whole device in a vertical direction by the upper universal joint 2 and the lower universal joint 10. The upper universal joint 2 is fixed by the first fixing screw 15, and the lower universal joint 10 is fixed by the second fixing screw 16.

[0048] S6. Simulate the sample 17. The sample 17 is rotated 0.5° or more around the x-axis, y-axis and z-axis to observe the fracture condition of the sample. The maximum angle between the two parallel linear guide rails 7 is obtained through the fracture condition.

[0049] Through simulation, it is found that when the sample 17 is rotated 0.5° or more with the x-axis, the sample 17 breaks from the clamping part due to stress concentration, instead of breaking from the middle. At this time, the maximum tensile load is also inaccurate, which leads to the failure of the experiment. When the sample 17 is rotated 0.5° or more with the y-axis, the sample 17 breaks from the neck due to stress concentration, instead of breaking from the middle. At this time, the maximum tensile load is also inaccurate, which leads to the failure of the experiment. When the sample 17 is rotated 0.5° or more with the z-axis, the sample 17 breaks from the neck due to stress concentration, instead of breaking from the middle. At this time, the maximum tensile load is also inaccurate, which leads to the failure of the experiment.

[0050] As can be seen from the above, the maximum angle between the sample 17 and the three axes is 0.5°, which can prevent the sample 17 from tilting due to unavoidable factors in the placement of the sample 17, thereby preventing the test failure. Figure 4 The stress cloud diagram of sample 17 with an offset of 0.5° around the z-axis shows that there is an obvious stress concentration phenomenon (the color is yellow-green) in the right clamping part, which is the same when rotated 0.5° around the x- and y-axes.

[0051] The maximum angle between the two parallel linear guide rails 7 is 0.5°, so that the sample 17 breaks from the middle during processing. If it is greater than 0.5°, it will break from the clamping part to prevent the inevitable error during processing and cause the experimental test failure. The cloud diagram of the simulation of the fracture from the clamping part is as follows Figure 5 As shown, Figure 5This is a cloud diagram of two parallel linear guides 7 with an angle of 0.5° in the yz plane. From the figure, it can be seen that there is an obvious stress concentration phenomenon in the clamping part on the right side (the color is yellowish green). The angle formed by the parallel linear guides 7 in other directions is 0.5°. When performing simulation, the error is smaller than the error of the universal testing machine, which can increase the success rate of the experiment.

[0052] S7. The universal testing machine selects the displacement control mode, and the first fixed installation part 1 is slowly moved upward at a set speed. The load-displacement curve on the testing machine software is observed. When the load-displacement curve shows a load drop, the stretching is stopped and the data is recorded.

[0053] S8. Remove the measured sample 17 and replace it with a new sample 17 to continue the test.

[0054]

[0055] The strength of sample 17 is calculated by formula (1), where P max represents the maximum load, and S represents the cross-sectional area of ​​the middle part of the glass.

[0056] Embodiment 1

[0057] The present invention provides a nested adaptive adjustment loading method for testing the tensile strength of sheet glass. The nested adaptive adjustment loading device for testing the tensile strength of sheet glass is used. In this embodiment, high-aluminum glass in sheet inorganic silicate glass is taken as an example. The width of the middle part of the glass is 3 mm, the thickness is 3 mm, and the cross section of the sample is a rectangular cross section. The method comprises the following steps:

[0058] S1. Prepare sample 17 and make preliminary preparations: Sample 17 is high aluminum glass in the sheet-like inorganic silicate glass. The thickness of sample 17 is 3 mm, the width is 3 mm, the test plane is the yz plane, and the test direction is parallel to the length direction of the sheet-like glass (z-axis direction).

[0059] S2. First, insert the parallel linear guide rails 7 on the lower fixture into the two limit spaces 8 of the upper fixture. The upper fixture can only slide up and down on the two parallel linear guide rails 7, further limiting the relative displacement left and right and inside and outside the surface, so that the upper fixture and the sample 17 remain vertical. The two parallel linear guide rails 7 are fixed on the lower fixture, and the parallel linear guide rails 7 and the upper fixture can slide up and down relative to each other.

[0060] S3. Fix the upper silicone gasket 4 in the first mounting groove 3 and the lower silicone gasket 12 in the second mounting groove 11 respectively. Use the upper silicone gasket 4 and the lower silicone gasket 12 to block the direct contact between the glass and the upper fixture and the lower fixture. This design is used when the contact surface between the fixture and the glass is not very smooth and there may be stress concentration. The low-modulus upper silicone gasket 4 and the lower silicone gasket 12 can provide the glass sample 17 with an opportunity to adapt to the side of the fixture groove.

[0061] S4. Place the sample 17 into the first mounting groove 3 and the second mounting groove 11, and cover the first mounting groove 3 with the upper pressure head cover 5 respectively, and fix the upper pressure head cover 5 with the first cover screw 6; cover the second mounting groove 11 with the lower pressure head cover 13, and fix the lower pressure head cover 13 with the second cover screw 14, so as to fix the sample 17 to prevent it from falling off and to prevent stress concentration from occurring due to the deviation between it and the yz plane.

[0062] S5. Clamp and fix the first fixing part 1 and the second fixing part respectively by a universal testing machine.

[0063] S6. The universal testing machine selects the displacement control mode, and the first fixed installation part 1 is slowly moved upward at the set speed. The universal testing machine stretches at a speed of 0.5 mm per minute, and the test temperature is 25°C. Observe the load-displacement curve on the testing machine software. When the load-displacement curve shows a drop in load, stop stretching and record the data. The load-displacement curve is as follows: Figure 6 shown.

[0064] S7. Remove the tested sample 17 (high aluminum glass) and replace it with a new sample 17 to continue the test.

[0065]

[0066] The strength of the sample high aluminum glass is calculated by formula (1), where P max represents the maximum load, and S represents the cross-sectional area of ​​the middle part of the glass.

[0067] The load displacement curve obtained for sample 17 (high aluminum glass) is as follows Figure 6 The fracture diagram after stretching is shown in Figure 7 As shown by Figure 6 It can be seen that the maximum load is 800N. The strength of the high-aluminum glass can be calculated to be 89MPa by formula (1). Since the silicone gasket is used, it has a certain degree of self-adaptation when stretched, so the displacement obtained is not the tensile displacement of the glass.

[0068] Embodiment 2

[0069] The specimen and operation steps used in this example are the same as those in Example 1, wherein the specimen is rotated 0.5° around the z-axis. The load displacement curve obtained is shown in FIG. Figure 8 As shown, the fracture diagram after stretching is Fig. 9 shown.

[0070] Depend on Figure 8 It can be seen that the maximum load is 530.9N. According to formula (1), the strength of this high-aluminum glass can be calculated to be 59MPa, which is obviously smaller than that in normal experiments.

[0071] The photograph of sample 17 after being rotated 0.5° around the z axis is shown in the figure below. Fig. 9 As shown, judging from the shape of the fracture, sample 17 may have been subjected to a large stress concentration when it broke, resulting in a sudden fracture at a specific position.

[0072] Embodiment 3

[0073] The samples and operation steps used in this example are basically the same as those in Example 2, that is, the upper silicone gasket 4 and the lower silicone gasket 12 with lower modulus in S3 are replaced with upper copper gaskets and lower copper gaskets with higher modulus.

[0074] The load displacement curve obtained when using a copper sheet with a larger modulus as a gasket is as follows Fig.10 As shown, the fracture diagram after stretching is Fig.11 As shown. Fig.10 As shown in the figure, the maximum load is 318N. The strength of this high-aluminum glass can be calculated to be 35MPa by formula (1). Since the copper sheet with a large modulus is used as a gasket, the tensile displacement is small. The gentle curve in front is generated by the self-adaptation of the universal joint. Since the modulus of the copper sheet is large, stress concentration is easily generated at the neck, causing the glass to break directly before reaching the limit load. Fig.10 shown.

[0075] Therefore, the present invention adopts the above-mentioned nested adaptive adjustment loading device and method for testing the tensile strength of sheet glass, adopts a double slide rail design, and two parallel linear guides are fixed on the lower clamp, so that the upper clamp slides on the two parallel linear guides, further limiting the left-right and inside-outside relative displacement, and using a silicone gasket to block the direct contact between the glass and the clamp. This design is used when the contact surface between the clamp and the glass is not very smooth and there may be stress concentration. The low-modulus silicone gasket can provide the glass sample with an opportunity to adapt to the side of the clamp groove, and is suitable for different types of sheet glass samples. The samples of the test method can be repeatedly installed and disassembled non-destructively for many times to avoid mechanical damage caused during the sample disassembly process.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A nested adaptive adjustment loading device for sheet glass tensile strength testing, characterized in that: It includes an upper mounting mechanism and a lower mounting mechanism, which are connected to each other via a sliding assembly. The sliding assembly includes parallel linear guide rails, the lower ends of which are fixed to the lower mounting mechanism, and the upper ends of which are slidably connected to the upper mounting mechanism.

2. The nested adaptive adjustment loading device for sheet glass tensile strength testing according to claim 1, characterized in that: The upper mounting mechanism comprises an upper clamp, the upper portion of the upper clamp is fixedly connected to the upper universal joint, and the upper universal joint is fixedly connected to the first fixed mounting portion via a first fixing screw.

3. The nested adaptive adjustment loading device for testing the tensile strength of sheet glass according to claim 2, characterized in that: The lower mounting mechanism comprises a lower clamp, the lower portion of the lower clamp is fixedly connected to the lower universal joint, and the lower universal joint is fixedly connected to the second fixed mounting portion via a second fixing screw.

4. The nested adaptive adjustment loading device for sheet glass tensile strength testing according to claim 3, characterized in that: A first mounting groove is provided in the middle of the upper clamp, an upper silicone gasket is fixed on the inner surface of the first mounting groove, an upper pressure head cover is provided at the first mounting groove, the upper pressure head cover is fixedly connected to the upper clamp by a first cover screw, and limited spaces are respectively provided on the left and right sides of the first mounting groove.

5. The nested adaptive adjustment loading device for testing the tensile strength of sheet glass according to claim 4, characterized in that: A second mounting groove is opened in the middle of the lower clamp, a lower silicone gasket is fixed on the inner surface of the second mounting groove, a lower pressure head cover is arranged at the second mounting groove, and the lower pressure head cover is fixedly connected to the lower clamp by a second cover screw.

6. The nested adaptive adjustment loading device for sheet glass tensile strength testing according to claim 5, characterized in that: The number of the parallel linear guide rails is two, and the two parallel linear guide rails are placed in two limit spaces.

7. A nested adaptive adjustment loading method for testing the tensile strength of sheet glass, using the nested adaptive adjustment loading device for testing the tensile strength of sheet glass according to claim 6, characterized in that: The following steps are involved: S1. Prepare samples and make preliminary preparations; S2. Insert the two parallel linear guide rails fixedly connected on the lower fixture into the two limit spaces of the upper fixture, further restrict the relative displacement of the upper and lower fixtures left and right and inside and outside the plane, so that the upper and lower fixtures and the sample remain vertical; S3, fixing the upper silicone gasket and the lower silicone gasket in the first mounting groove and the second mounting groove respectively, blocking direct contact between the glass and the upper clamp and the lower clamp; S4, place the sample into the first installation slot and the second installation slot, cover the first installation slot with an upper pressure head cover, and fix the upper pressure head cover to the upper fixture with a first cover screw, cover the second installation slot with a lower pressure head cover, and fix the lower pressure head cover to the lower fixture with a second cover screw; S5. Clamp and fix the first fixed installation part and the second fixed installation part respectively by a universal testing machine, and make the whole device in a vertical direction by an upper universal joint and a lower universal joint, the upper universal joint is fixed by a first fixing screw, and the lower universal joint is fixed by a second fixing screw; S6. Simulate the sample, rotate the sample around the x-axis, y-axis and z-axis by 0.5° or more to observe the fracture condition of the sample, and obtain the maximum angle between the two parallel linear guides through the fracture condition; S7, the universal testing machine selects the displacement control mode, moves the first fixed installation part slowly upward at the set speed, observes the load-displacement curve on the testing machine software, and stops stretching when the load-displacement curve shows a load drop, and records the data; S8. Remove the measured sample and replace it with a new sample to continue the test.

8. A nested adaptive adjustment loading method for sheet glass tensile strength testing, characterized in that: The sample in S1 is a sheet of inorganic silicate glass with a thickness of 3 mm and an intermediate width of 3-6 mm. The test plane is the yz plane. The test direction is parallel to the length direction of the sheet glass, that is, the z direction. The thickness direction is the y direction and the width direction is the x direction.

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