Testing method for tensile strength of flexible glass

Abstract

An embodiment of the present invention provides a method for testing the tensile strength of flexible glass. The method comprises the following steps: obtaining the elastic modulus E of a first flexible glass sample through a cantilever beam vibration test; obtaining the distance D between opposite ends of the second flexible glass sample in its longitudinal direction under extreme bending conditions through a two-point bending test; establishing a three-dimensional model of the flexible glass that is in a preset proportion to the second flexible glass sample in the two-point bending test; applying a constraint on the elastic modulus E to the three-dimensional model of the flexible glass; and applying the constraint to the three-dimensional model of the flexible glass so that the distance D1 between opposite ends of the flexible glass sample in its longitudinal direction is in a preset proportion to the distance D; and obtaining the tensile strength of the flexible glass. The method for testing the tensile strength of flexible glass according to the embodiment of the present invention can effectively test the tensile strength of thin, flexible, and brittle materials such as flexible glass.

Description

Technical Field

[0001] The invention belongs to the technical field of flexible glass detection, and particularly relates to a method for detecting the tensile strength of flexible glass. Background Art

[0002] Flexible glass is glass that is thinned to tens of microns in thickness. Flexible glass has broad application prospects in flexible display fields such as folding screens. However, flexible glass currently suffers from problems such as breakage and cracking during use. The main reason is that the current design and test evaluation methods for its mechanical reliability are still imperfect, which seriously hinders the effective design, analysis and optimization of products and processes.

[0003] As fundamental material performance parameters, material mechanical properties such as tensile strength serve as core parameters for the reliability design and analysis of related material / structural products. Currently, the primary methods for measuring tensile strength in the field of material mechanics include standard part tensile testing, disc splitting testing, and three- and four-point bending tests. However, these methods have limitations for flexible glass, which possesses both the flexibility of tough materials and the fragility of brittle materials, and are unable to effectively test the tensile strength of flexible glass. Summary of the Invention

[0004] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0005] To this end, an embodiment of the present invention provides a method for testing the tensile strength of flexible glass. The method can effectively test the tensile strength of thin, soft and brittle materials such as flexible glass.

[0006] The method for testing the tensile strength of flexible glass provided in an embodiment of the present invention comprises the following steps:

[0007] S10: performing a cantilever beam vibration test on the first flexible glass sample to obtain an elastic modulus E of the first flexible glass sample;

[0008] S20: performing a two-point bending test on the second flexible glass sample to obtain a distance D between two opposite ends of the second flexible glass sample in a longitudinal direction under an extreme bending state;

[0009] S30: establishing a flexible glass three-dimensional model that is in a preset proportion to the second flexible glass sample in step S20, and applying the elastic modulus E obtained in step S10 to the flexible glass three-dimensional model, so that the flexible glass three-dimensional model is bent and deformed until a distance D1 between opposite ends in a longitudinal direction thereof is in a preset proportion to the distance D obtained in step S20;

[0010] S40: Calculate and obtain the tensile stress of the outer curved surface of the flexible glass three-dimensional model in the extreme bending state, where the tensile stress is the tensile strength of the flexible glass.

[0011] Furthermore, the cantilever beam vibration test in step S10 includes the following steps:

[0012] S11: fixing one end of the first flexible glass sample, wherein the other end of the first flexible glass sample constitutes a signal portion;

[0013] S12: applying a predetermined force to the first flexible glass sample to cause the first flexible glass sample to vibrate;

[0014] S13: Acquire vibration data of the first flexible glass sample and analyze the vibration data of the first flexible glass sample to obtain a first-order natural frequency of the first flexible glass sample;

[0015] S14: Repeat steps S12 and S13 multiple times to obtain multiple first-order natural frequencies of the first flexible glass sample, and calculate an average value of the first-order natural frequencies of the first flexible glass sample.

[0016] S15: Calculate the elastic modulus E of the first flexible glass sample using the average value of the first-order natural frequency.

[0017] Furthermore, in step S13, vibration data of the first flexible glass sample is acquired through a signal collector.

[0018] Furthermore, in the step S13, vibration data of the first flexible glass sample is obtained by arranging marking points on the signal portion and photographing the vibration process of the first flexible glass sample using a high-speed camera.

[0019] Furthermore, the two-point bending test in step S20 includes the following steps:

[0020] S21: providing two support seats capable of sliding relative to each other along the extension direction of the first straight line;

[0021] S22: placing opposite ends of the second flexible glass sample in the length direction against the corresponding support seats, respectively, so that the length direction of the second flexible glass sample is consistent with the extension direction of the first straight line;

[0022] S23: applying a slight deflection to the middle portion of the second flexible glass sample so that the two support seats can move relative to each other along the extension direction of the first straight line, thereby gradually bending and deforming the second flexible glass sample;

[0023] S24: When the second flexible glass sample is bent and deformed to an extreme bending state, the distance between the two support seats is recorded. The distance between the two support seats is the distance D between the two ends of the second flexible glass sample.

[0024] Furthermore, the ultimate bending state of the second flexible glass sample is a state in which the flexible glass sample is bent and deformed to the point of fracture.

[0025] Furthermore, in step S30 , a slight deflection is applied to the middle position of the flexible glass three-dimensional model to guide the flexible glass three-dimensional model to continue bending.

[0026] Furthermore, in the step S30, a three-dimensional model of the flexible glass is established in finite element numerical analysis software.

[0027] Furthermore, in step S30, a fixed constraint can be applied to one of the two opposite ends in the length direction of the flexible glass three-dimensional model, and a displacement constraint can be applied to the other of the two opposite ends in the length direction of the flexible glass three-dimensional model, so as to achieve relative movement of the two opposite ends in the length direction of the flexible glass three-dimensional model, thereby causing the flexible glass three-dimensional model to bend and deform.

[0028] Furthermore, in step S30, displacement constraints may be simultaneously applied to the two opposite ends of the flexible glass three-dimensional model in the length direction to enable the two opposite ends of the flexible glass three-dimensional model to move relative to each other, thereby causing the flexible glass three-dimensional model to bend and deform.

[0029] The method for testing the tensile strength of flexible glass according to an embodiment of the present invention determines the elastic modulus E of a first flexible glass sample through a cantilever beam vibration test, determines the distance D between the longitudinal ends of a second flexible glass sample under extreme bending conditions through a two-point bending test, and constructs a three-dimensional model of the flexible glass at a predetermined ratio to the second flexible glass sample. Using the elastic modulus E and the distance D as constraints on the three-dimensional model, the tensile stress on the outer curved surface of the three-dimensional model is calculated to determine the tensile strength of the flexible glass. Therefore, the method for testing the tensile strength of flexible glass according to an embodiment of the present invention can effectively test the tensile strength of flexible glass. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 4 is a flow chart of a method for detecting the tensile strength of flexible glass according to an embodiment of the present invention. DETAILED DESCRIPTION

[0031] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0032] The following is based on the attached Figure 1 A method for testing the tensile strength of flexible glass provided by an embodiment of the present invention is described.

[0033] Figure 1 A flow chart of a method for testing the tensile strength of flexible glass provided in an embodiment of the present invention, the method comprising the following steps:

[0034] S10: performing a cantilever beam vibration test on the first flexible glass sample to obtain an elastic modulus E of the first flexible glass sample;

[0035] S20: performing a two-point bending test on the second flexible glass sample to obtain a distance D between two opposite ends of the second flexible glass sample in a longitudinal direction under an extreme bending state;

[0036] S30: establishing a three-dimensional flexible glass model that is in a preset proportion to the second flexible glass sample in step S20, and applying a constraint of the elastic modulus E obtained in step S10 to the three-dimensional flexible glass model, so that the three-dimensional flexible glass model is bent and deformed until a distance D1 between two opposite ends in a longitudinal direction thereof is in a preset proportion to the distance D obtained in step S20;

[0037] S40: Calculate and obtain the tensile stress of the outer curved surface of the flexible glass three-dimensional model in the ultimate bending state, where the tensile stress is the tensile strength of the flexible glass.

[0038] The method for testing the tensile strength of flexible glass according to an embodiment of the present invention combines a cantilever beam vibration test method, a two-point bending test method, and a numerical calculation and analysis method, thereby effectively testing the tensile strength of thin, flexible, and brittle materials such as flexible glass. Specifically, the elastic modulus E of a first flexible glass sample is determined through a cantilever beam vibration test, and the distance D between opposite ends of the length of a second flexible glass sample under extreme bending is determined through a two-point bending test. A three-dimensional model of the flexible glass is established at a predetermined ratio to the second flexible glass sample, and the elastic modulus E and distance D are used as constraints of the three-dimensional flexible glass model. The tensile stress on the outer curved surface of the three-dimensional flexible glass model is calculated, and this tensile stress represents the tensile strength of the flexible glass sample.

[0039] Therefore, the method for testing the tensile strength of flexible glass according to the embodiment of the present invention can effectively test the tensile strength of flexible glass.

[0040] like Figure 1 FIG2 is a flow chart of a method for detecting the tensile strength of flexible glass according to an embodiment of the present invention. The method comprises the following steps:

[0041] S10: Perform a cantilever beam vibration test on the first flexible glass sample to obtain an elastic modulus E of the first flexible glass sample. The first flexible glass sample may adopt the sample specifications required by the national standard GB / T 37788-2019. The specific sample specifications can be selected according to test requirements. Specifically, the cantilever beam vibration test may include the following steps:

[0042] S11: Secure one end of the first flexible glass sample. The other end of the first flexible glass sample constitutes the signal portion. Specifically, 502 glue or other high-strength, instant-drying liquid adhesive can be used to secure one end of the first flexible glass sample. The bond length should account for 20% of the total length of the first flexible glass sample. The signal portion serves as the sampling area for vibration data of the first flexible glass sample.

[0043] S12: applying a predetermined force to the first flexible glass sample to cause the first flexible glass sample to vibrate. The predetermined force may be set according to the provisions of the national standard GB / T 37788-2019;

[0044] S13: Acquire vibration data of the first flexible glass sample and analyze the vibration data of the first flexible glass sample to obtain a first-order natural frequency of the first flexible glass sample.

[0045] Specifically, in step S24, vibration data of the first flexible glass sample can be obtained by a signal collector, which can be a laser rangefinder. The laser rangefinder measures the change in distance between the signal portion and the first flexible glass sample during vibration, thereby obtaining the vibration data of the first flexible glass sample.

[0046] Specifically, in step S24, marking points may be arranged on the signal portion and a high-speed camera may be used to capture the vibration process of the first flexible glass sample. Specifically, the high-speed camera records the vibration amplitude of the marking points to obtain vibration data of the first flexible glass sample.

[0047] S14: Repeat steps S12 and S13 multiple times to obtain multiple first-order natural frequencies of the first flexible glass sample and obtain an average of the first-order natural frequencies. Specifically, steps 12 and 13 can be repeated multiple times for a single first flexible glass sample to obtain multiple first-order natural frequencies; steps 12 and 13 can also be repeated multiple times for multiple first flexible glass samples to obtain multiple first-order natural frequencies. It is worth noting that when conducting experiments using multiple first flexible glass samples, the multiple first flexible glass samples may have different sizes, but they must be from the same batch of flexible glass. By analyzing and calculating the vibration data obtained in step S14 to obtain multiple first-order natural frequencies of the first flexible glass sample and then averaging them, the accuracy of the test results can be improved.

[0048] S15: Calculate the elastic modulus E of the first flexible glass sample using the average value of the first-order natural frequency. Specifically, the elastic modulus E of the first flexible glass sample is calculated using the following formula:

[0049]

[0050] Wherein, E is the glass elastic modulus of the first flexible glass sample, in Pascal (Pa); f is the average value of the first-order natural frequency of the first flexible glass sample, in Hertz (HZ); L is the length of the first flexible glass, in millimeter (mm); m is the mass of the first flexible glass sample, in gram (g); b is the width of the first flexible glass sample, in millimeter (mm); h is the thickness of the first flexible glass sample, in millimeter (mm); l is the length of the first flexible glass sample, in millimeter (mm).

[0051] S20: Perform a two-point bending test on the second flexible glass sample and determine the distance D between opposite ends of the second flexible glass sample in the longitudinal direction under an extreme bending state, wherein the extreme bending state of the second flexible glass sample is a state in which the second flexible glass sample is bent and deformed to the point of fracture. It is understood that the dimensions of the second flexible glass sample may differ from those of the first flexible glass sample, but the second flexible glass sample and the first flexible glass sample are obtained from the same batch of flexible glass to ensure that the second flexible glass sample and the first flexible glass sample have the same elastic modulus E.

[0052] Specifically, the two-point bending test in step S20 includes the following steps:

[0053] S21: providing two support seats capable of sliding relative to each other along the extension direction of the first straight line;

[0054] S22: The two opposite ends of the second flexible glass sample in the length direction are respectively aligned with the corresponding support seats, and the length direction of the second flexible glass sample is consistent with the extension direction of the first straight line; specifically, in order to facilitate the two ends of the second flexible glass sample to be better aligned and fixed with the support seat, the shape of the fixing seat can be set according to actual conditions, such as L-shaped.

[0055] S23: applying a slight deflection to the middle portion of the second flexible glass sample so that the two support seats can move relative to each other along the extension direction of the first straight line, thereby gradually bending and deforming the second flexible glass sample;

[0056] S24: When the second flexible glass sample is bent and deformed to an extreme bending state, the distance between the two support bases is recorded. The distance between the two support bases is the distance D between opposite ends of the second flexible glass sample in the longitudinal direction in the extreme bending state. Specifically, the extreme bending state of the second flexible glass sample is the state in which the second flexible glass sample is bent and deformed to the point of fracture. In other words, the state of the second flexible glass sample at the moment of bending and deforming to fracture is the extreme bending state of the second flexible glass sample.

[0057] S30: A three-dimensional flexible glass model is established at a preset ratio relative to the second flexible glass sample in step S20. The elastic modulus E obtained in step S10 is constrained to the three-dimensional flexible glass model. The constrained three-dimensional flexible glass model is bent and deformed until the distance D1 between its two opposite ends along its length is in a preset ratio relative to the distance D obtained in step S20. Specifically, within the finite element numerical analysis software, the three-dimensional flexible glass model is established at a preset ratio based on the dimensions of the second flexible glass sample. It will be appreciated that in actual practice, the preset ratio can be determined based on actual circumstances. For example, if the experimental platform is less equipped, the preset ratio can be a reduced ratio. Specifically, the three-dimensional flexible glass model is established based on the dimensions of the second flexible glass sample, but the dimensions of the second flexible glass sample are reduced by the preset ratio. This reduces the computational workload of the experimental platform, significantly shortens experimental time, and further improves experimental efficiency.

[0058] Furthermore, in step S30 , a slight deflection deformation may be applied to the middle position of the flexible glass three-dimensional model to guide the flexible glass three-dimensional model to continue bending.

[0059] Furthermore, in step S30, a fixed constraint can be applied to one of the two opposite ends in the length direction of the flexible glass three-dimensional model, and a displacement constraint can be applied to the other of the two opposite ends in the length direction of the flexible glass three-dimensional model, so that the two opposite ends in the length direction of the flexible glass three-dimensional model can move relative to each other, thereby causing the flexible glass three-dimensional model to bend and deform.

[0060] Furthermore, in step S30 , displacement constraints may be simultaneously applied to the two opposite ends of the flexible glass 3D model in the length direction to enable the two opposite ends of the flexible glass 3D model to move relative to each other, thereby causing the flexible glass 3D model to bend and deform.

[0061] S40: Calculate the tensile stress on the outer curved surface of the flexible glass three-dimensional model in the ultimate bending state. This tensile stress represents the tensile strength of the flexible glass. By simulating the bending process of the flexible glass sample using finite element numerical analysis software, the stress on the outer curved surface of the flexible glass sample is tensile stress. Therefore, the tensile stress on the outer curved surface of the flexible glass three-dimensional model when bent and deformed to the ultimate state can be simulated and calculated. This tensile stress represents the maximum tensile stress that the outer curved surface of the flexible glass three-dimensional model can withstand. Therefore, the tensile stress on the outer curved surface of the flexible glass three-dimensional model when bent and deformed to the ultimate state represents the tensile strength of the flexible glass three-dimensional model. Because the elastic modulus of the flexible glass three-dimensional model is consistent with the elastic modulus E of each of the first and second flexible glass samples, the tensile strength of the flexible glass three-dimensional model is consistent with the tensile strength of each of the first and second flexible glass samples, thereby determining the tensile strength of the flexible glass.

[0062] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0063] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0064] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0065] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0066] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples without contradiction.

[0067] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A method for testing the tensile strength of flexible glass, characterized in that: The steps include: S10: performing a cantilever beam vibration test on the first flexible glass sample to obtain an elastic modulus E of the first flexible glass sample; S20: performing a two-point bending test on the second flexible glass sample to obtain a distance D between two opposite ends of the second flexible glass sample in a longitudinal direction under an extreme bending state; S30: establishing a flexible glass three-dimensional model that is in a preset proportion to the second flexible glass sample in step S20, and applying the elastic modulus E obtained in step S10 to the flexible glass three-dimensional model, so that the flexible glass three-dimensional model is bent and deformed until a distance D1 between opposite ends in a longitudinal direction thereof is in a preset proportion to the distance D obtained in step S20; S40: Calculate and obtain the tensile stress of the outer curved surface of the flexible glass three-dimensional model in the extreme bending state, where the tensile stress is the tensile strength of the flexible glass.

2. The method for testing the tensile strength of flexible glass according to claim 1, characterized in that: The cantilever beam vibration test in step S10 includes the following steps: S11: fixing one end of the first flexible glass sample, wherein the other end of the first flexible glass sample constitutes a signal portion; S12: applying a predetermined force to the first flexible glass sample to cause the first flexible glass sample to vibrate; S13: Acquire vibration data of the first flexible glass sample and analyze the vibration data to obtain a first-order natural frequency of the first flexible glass sample; S14: Repeat steps S12 and S13 multiple times to obtain multiple first-order natural frequencies of the first flexible glass sample, and calculate an average value of the first-order natural frequencies of the first flexible glass sample; S15: Calculate the elastic modulus E of the first flexible glass sample using the average value of the first-order natural frequency.

3. The method for testing the tensile strength of flexible glass according to claim 2, characterized in that: In the step S13, vibration data of the first flexible glass sample is acquired through a signal collector.

4. The method for testing the tensile strength of flexible glass according to claim 2, wherein: In the step S13 , marking points are arranged on the signal portion, and a high-speed camera is used to photograph the vibration process of the first flexible glass sample to obtain vibration data of the first flexible glass sample.

5. The method for testing the tensile strength of flexible glass according to claim 1, characterized in that: The two-point bending test in step S20 includes the following steps: S21: providing two support seats capable of sliding relative to each other along the extension direction of the first straight line; S22: placing opposite ends of the second flexible glass sample in the length direction against the corresponding support seats, respectively, so that the length direction of the second flexible glass sample is consistent with the extension direction of the first straight line; S23: applying a slight deflection to the middle portion of the second flexible glass sample so that the two support seats can move relative to each other along the extension direction of the first straight line, thereby gradually bending and deforming the second flexible glass sample; S24: When the second flexible glass sample is bent and deformed to an extreme bending state, the distance between the two support seats is recorded. The distance between the two support seats is the distance D between the two ends of the second flexible glass sample.

6. The method for testing the tensile strength of flexible glass according to claim 1, characterized in that: The ultimate bending state of the second flexible glass sample is a state in which the second flexible glass sample is bent and deformed to fracture.

7. The method for testing the tensile strength of flexible glass according to claim 1, characterized in that: In the step S30 , a slight deflection is applied to the middle position of the flexible glass three-dimensional model to guide the flexible glass three-dimensional model to continue bending.

8. The method for testing the tensile strength of flexible glass according to claim 1, characterized in that: In the step S30, a three-dimensional model of the flexible glass is established in finite element numerical analysis software.

9. The method for testing the tensile strength of flexible glass according to claim 1, characterized in that: In step S30, a fixed constraint is applied to one of the two opposite ends in the length direction of the flexible glass three-dimensional model, and a displacement constraint is applied to the other of the two opposite ends in the length direction of the flexible glass three-dimensional model, so that the two opposite ends in the length direction of the flexible glass three-dimensional model can move relative to each other, thereby causing the flexible glass three-dimensional model to bend and deform.

10. The method for testing the tensile strength of flexible glass according to claim 1, wherein: In step S30, displacement constraints are simultaneously applied to the two opposite ends of the flexible glass three-dimensional model in the length direction, so that the two opposite ends of the flexible glass three-dimensional model in the length direction can move relative to each other, thereby causing the flexible glass three-dimensional model to bend and deform.

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