A Thermal Stress Simulation Method during the Tempering Process of Ultra-Thin Glass

Abstract

The present invention relates to a thermal stress simulation method during the tempering process of ultra-thin glass, comprising the following steps: S1, creating an ultra-thin glass plate tempering model, selecting a group of ultra-thin glass plates with vertical jets as stress simulation objects, establishing a calculation domain for the ultra-thin glass, wherein the calculation domain includes a flow field region inside a nozzle, a flow field region at the interface between the nozzle and the glass plate, and a solid field region of the glass plate; S2, defining material properties, discretizing the model into a grid model after solid modeling, first defining the elastic modulus E and Poisson's ratio μ of the glass by defining unit properties and grid generation control, then setting the flow field material to air, and setting the changes of the thermophysical parameters of the glass with temperature; providing accurate numerical values for the thermal stress simulation of the ultra-thin tempered glass, improving the accuracy of the stress simulation results, selecting a suitable glass quenching optimization scheme from the scheme, and providing a scheme for further research in the future.

Description

Technical Field

[0001] The invention relates to a thermal stress simulation method during the tempering process of ultra-thin glass. Background Art

[0002] With the development of the photovoltaic industry, the quality requirements for tempered glass are becoming increasingly stringent, and the thickness of tempered glass is becoming increasingly smaller. However, the stress measurement devices currently available on the market are unable to measure the stress changes in glass in real time. There are generally two methods for measuring glass stress: observing residual stress using orthogonal polarization and measuring surface stress using sensor patches. However, both methods have their own drawbacks. Orthogonal polarization cannot observe the stress formation process and can only be tested after the stress is formed. Testing with sensors also has some problems. The extremely thin thickness of the glass used makes it difficult for the sensor element to accurately measure. The tempering process temperature is around 695°C, which the sensitive elements of the stress meter cannot withstand. At the same time, the weak vibrations caused by the jet impact on the glass sheet make it impossible to measure the displacement frequency, resulting in a series of problems such as significant errors in the test results. However, due to market requirements, it is necessary to study the tempering process.

[0003] Currently, the main approach adopted is simulation, but the material properties currently selected for simulation of glass sheets are generally characterized as elasto-plastic, which is inaccurate. During the heating process, stress relaxation will occur in the glass, and the shape of the glass will slowly change from an elasto-plastic to a viscoelastic body. The specific heat capacity, heat transfer coefficient, and thermal expansion coefficient of the glass will all undergo nonlinear changes with temperature. The fact that ultra-thin glass is simultaneously affected by the coupling of heat, fluid, and solid fields during the tempering process also brings some difficulties to the simulation calculations. At the same time, in recent years, the simulation research on glass tempering has basically studied the arrangement of nozzle arrays, and the effects of different nozzles under different working conditions have basically not been considered. Finally, due to the relatively complex physical field of the glass tempering process, the flow field grid needs to be encrypted, which increases the number of grids and the difficulty of calculation. Summary of the Invention

[0004] The technical problem to be solved by the present invention is: in order to solve the problems of complex calculation and subsequent difficulty in optimization in the current simulation of ultra-thin tempered glass, a thermal stress simulation method for the ultra-thin glass tempering process is provided.

[0005] The technical solution adopted by the present invention to solve the technical problem is: a method for simulating thermal stress during the tempering process of ultra-thin glass, comprising the following steps:

[0006] S1. Create an ultra-thin glass tempering model. Select a set of ultra-thin glass plates with vertical jets as stress simulation objects and establish a computational domain for the ultra-thin glass. The computational domain includes a fluid domain and a solid domain. The fluid domain includes the flow field area inside the nozzle and the flow field area at the junction of the nozzle and the glass plate. The solid domain is the solid field area of the glass plate.

[0007] S2. Define material properties. After solid modeling, the model needs to be discretized into a mesh model. By defining unit properties and mesh generation control, first define the elastic modulus E and Poisson's ratio μ of the glass, and then set the flow field material to air. Set the temperature variation of the glass's thermophysical parameters. Based on known literature data, fit the specific heat capacity c of the glass. p The specific heat capacity c of glass is defined by the relationship between the thermal conductivity λ and the thermal expansion coefficient α as a function of temperature. p , thermal conductivity λ and thermal expansion coefficient α;

[0008] S3. Mesh the ultra-thin glass model and its computational domain, using common-node meshes for both solid and fluid interfaces. Based on the actual simulation environment, the solid and fluid domains of the ultra-thin glass model are segmented, and the number of boundary cells is adjusted to generate the solid and fluid domain meshes, respectively.

[0009] S4. Define the physical field, apply the same boundary conditions to the grid model, and set the coupling of the solid field, flow field, and temperature field. Fix the bottom surface of the glass plate, select the stress field calculation for the solid physics model, set the initial temperature of the glass to 953K, set the nozzle flow area around the wall, set the temperature to the actual inlet temperature, set the inlet of the flow field area inside the nozzle as the velocity inlet, and set the outlet of the flow field area at the junction of the nozzle and the glass plate as the pressure outlet;

[0010] S5. Load the solver and load the physical field settings of the model into the solver. Set the variable parameter to parametric sweep and calculate the single-hole nozzle model with thickness h of 1.5 mm, 2 mm, and 3 mm, ratios H / D of jet height to nozzle bottom equivalent diameter of 0.2, 0.4, 0.6, 0.8, and 1.0, and jet Reynolds numbers Re of 8000, 15000, and 20000.

[0011] S6. Result Analysis: Analyze the simulation results of the previous solver. First, compare them with theoretical research results on the common glass tempering process and the changes in thermal stress during glass forming. Then, analyze the forming effects of glass thermal stress under different parameters and select the optimal solution to improve the glass quenching efficiency.

[0012] S7. Change the nozzle model shape and repeat the above steps until all calculations are complete. By analyzing the results and comparing the strengths and weaknesses of each nozzle, the optimal solution for the optimal nozzle shape is selected. This provides precise numerical values for ultra-thin tempered glass thermal stress simulation, improves the accuracy of stress simulation results, and allows for the selection of appropriate glass quenching optimization solutions, providing a solution for further research.

[0013] In some preferred embodiments, in step S1, when simplifying the ultra-thin glass model, because the ultra-thin glass tempering model is symmetrical about both the XOZ and YOZ planes, only one-quarter of the model needs to be created to reduce the number of computational grids. The nozzle shape can be cylindrical, frustum, or other, and the nozzle can be simulated at any angle. Repeated experiments are conducted to select an appropriate jet quenching solution.

[0014] In some preferred embodiments, in step S2, when calculating the thermal stress of the glass tempering process, the glass will gradually transform from an elastic-plastic body to a viscoelastic body, which has a significant impact on the residual stress results under the stress relaxation state. For this, the specific heat capacity c of the glass is fitted. p The relationship between the thermal conductivity λ and the thermal expansion coefficient α and the temperature can be used to more accurately calculate the thermal stress changes in the glass creep process.

[0015] In some preferred embodiments, in step S3, when dividing the surface mesh, to reduce the number of computational meshes and computation time, 1 / 4 of the ultra-thin glass tempered pattern is selected. The fluid domain is divided and swept using an O-shaped mesh, while the solid domain is divided and swept using an O-shaped mesh spread to the four edges within a single domain. A boundary layer is set for the fluid domain with a growth factor of 1.2 and a number of layers of 3.

[0016] In some preferred embodiments, in step S4, a coupled calculation of the flow field, temperature field, and solid field is performed on the ultra-thin glass computational domain. The bottom surface of the glass plate is fixed, the stress field calculation is selected for the solid physics model, and the initial temperature of the glass is set to 953 K. The nozzle flow domain is set to the wall surface, the temperature is set to the actual inlet temperature, the inlet of the flow field region inside the nozzle is set to the velocity inlet, and the outlet of the flow field region at the junction of the nozzle and the glass plate is set to the pressure outlet. The calculation range is 1 / 4 of the ultra-thin tempered glass model, so symmetry constraints are set at the symmetric interfaces of the model.

[0017] In some preferred embodiments, in steps S5 and S6, the thickness of the glass plate h, the ratio of the jet height to the equivalent diameter of the nozzle bottom surface H / D, and the jet Reynolds number Re are changed simultaneously in a single calculation, thereby reducing the number of calculations, simplifying the calculation difficulty and time, and testing the changes in thermal stress under different parameters at the same time, selecting the optimal solution, and improving the quenching efficiency of ultra-thin glass.

[0018] In some preferred embodiments, in step S7, the nozzle model shape is modified, and the above steps are repeated. The results are analyzed to determine the strengths and weaknesses of each nozzle, and the optimal solution for the optimal nozzle shape is selected. This provides precise numerical values for ultra-thin tempered glass thermal stress simulation, improves the accuracy of stress simulation results, and enables selection of appropriate glass quenching optimization solutions, providing a solution for further research.

[0019] The beneficial effects of the present invention are:

[0020] (1) The selected nozzle shape can be cylindrical, truncated cone or other shapes. The nozzle can be simulated at any angle. Repeated experiments are conducted to select the appropriate jet quenching scheme.

[0021] (2) When calculating the thermal stress of glass during tempering, the glass will gradually transform from an elastic-plastic body to a viscoelastic body, which has a significant impact on the residual stress results under stress relaxation. To solve this problem, the specific heat capacity c of the glass is fitted. p The relationship between the thermal conductivity λ and the thermal expansion coefficient α and the temperature can be used to more accurately calculate the thermal stress changes in the glass creep process.

[0022] (3) Because the ultra-thin glass tempering model is symmetrical about the XOZ plane and the YOZ plane, in order to reduce the number of computational grids and thus improve the computational time and simulation efficiency, only 1 / 4 of the model needs to be established when building the model.

[0023] (4) A single calculation can simultaneously change the glass plate thickness h, the ratio of the jet height to the equivalent diameter of the nozzle bottom surface H / D, and the jet Reynolds number Re, reducing the number of calculations, simplifying the calculation difficulty and time, and at the same time testing the changes in thermal stress under different parameters, selecting the optimal solution, and improving the quenching efficiency of ultra-thin glass.

[0024] (5) At the same time, within 3 seconds after the glass tempering is completed, the thermal stress distribution change line at a certain time can be randomly extracted to realize real-time stress calculation.

[0025] (6) It provides accurate numerical values for the thermal stress simulation of ultra-thin tempered glass, improves the accuracy of stress simulation results, and selects appropriate glass quenching optimization schemes, providing solutions for further research in the future. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present invention will be further described below with reference to the accompanying drawings and examples.

[0027] Figure 1 is a principle block diagram of an embodiment of the present invention;

[0028] Figure 2 This is a solid modeling diagram of an embodiment of the present invention;

[0029] Figure 3A cross-sectional grid diagram of an embodiment of the present invention;

[0030] Figure 4 This is a graph showing the normal stress variation results of an embodiment of the present invention;

[0031] Figure 5 This is a diagram showing the physical principle of double-sided operation according to an embodiment of the present invention. DETAILED DESCRIPTION

[0032] The present invention is further described in detail below in conjunction with the embodiments:

[0033] The present invention is not limited to the following specific embodiments. Based on the disclosure of the present invention, a person skilled in the art may adopt a variety of other specific embodiments to implement the present invention. Any simple changes or modifications made to the design structure and concept of the present invention fall within the scope of protection of the present invention. It should be noted that the embodiments and features of the embodiments of the present invention may be combined with each other unless they conflict.

[0034] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like 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 cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0035] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0036] like Figure 1-5 As shown, the specific embodiments of the present invention are further described below with reference to the accompanying drawings:

[0037] A method for simulating thermal stress during the tempering process of ultra-thin glass comprises the following steps:

[0038] S1. Create an ultra-thin glass tempering model. Select a set of ultra-thin glass plates with vertical jets as stress simulation objects. Establish a computational domain for the ultra-thin glass. The computational domain includes the flow field region inside the nozzle, the flow field region at the interface between the nozzle and the glass plate, and the solid field region of the glass plate. The flow field region inside the nozzle and the flow field region at the interface between the nozzle and the glass plate are fluid domains, and the solid field region of the glass plate is a solid domain.

[0039] S2. Define material properties. After solid modeling, the model needs to be discretized into a mesh model. By defining unit properties and mesh generation control, first define the elastic modulus E and Poisson's ratio μ of the glass, and then set the flow field material to air. Set the temperature variation of the glass's thermophysical parameters. Based on known literature data, fit the specific heat capacity c of the glass. p The specific heat capacity c of glass is defined by the relationship between the thermal conductivity λ and the thermal expansion coefficient α as a function of temperature. p , thermal conductivity λ and thermal expansion coefficient α.

[0040] S3. Mesh the ultra-thin glass model and its computational domain, using common-node meshes for both solid and fluid interfaces. Based on the actual simulation environment, the solid and fluid domains of the ultra-thin glass model are segmented, and the number of boundary cells is adjusted to generate the solid and fluid domain meshes, respectively.

[0041] S4. Define the physical field, apply the same boundary conditions to the grid model, and set the coupling of the solid field, flow field, and temperature field. Fix the bottom surface of the glass plate, select the stress field calculation for the solid physics model, set the initial temperature of the glass to 953K, set the nozzle flow area around the wall, set the temperature to the actual inlet temperature, set the inlet of the flow field area inside the nozzle as the velocity inlet, and set the outlet of the flow field area at the junction of the nozzle and the glass plate as the pressure outlet;

[0042] S5. Load the solver and apply the model's physical field settings to the solver. Set the variable parameter to a parametric sweep and perform calculations for a single-hole nozzle model with thicknesses h of 1.5 mm, 2 mm, and 3 mm, jet height to nozzle base equivalent diameter ratios H / D of 0.2, 0.4, 0.6, 0.8, and 1.0, and jet Reynolds numbers Re of 8,000, 15,000, and 20,000.

[0043] S6. Results Analysis: Analyze the simulation results from the previous solver. First, compare them with theoretical research results on the common glass tempering process and the changes in thermal stress during glass forming. Then, analyze the forming effects of glass thermal stress under different parameters and select the optimal solution to improve glass quenching efficiency.

[0044] S7: Change the nozzle model shape and repeat steps S1-S6 until all calculations are complete. By analyzing the results and assessing the strengths and weaknesses of each nozzle, the optimal nozzle shape solution is selected. This provides precise numerical values for ultra-thin tempered glass thermal stress simulation, improves the accuracy of stress simulation results, and enables selection of appropriate glass quenching optimization solutions, providing a basis for further research.

[0045] In step S1, the ultra-thin glass model is simplified. Because the ultra-thin glass tempering model is symmetrical about both the XOZ and YOZ planes, only one-quarter of the model needs to be created to reduce the number of computational grids. The nozzle shape can be cylindrical, frustum, or other, and the nozzle can be simulated at any angle. Repeated experiments are performed to select the appropriate jet quenching solution.

[0046] In step S2, when calculating the thermal stress of the glass during tempering, the glass will gradually transform from an elastic-plastic body to a viscoelastic body, which has a significant impact on the residual stress results under stress relaxation. p The relationship between the thermal conductivity λ and the thermal expansion coefficient α and the temperature can be used to more accurately calculate the thermal stress changes in the glass creep process.

[0047] In step S3, when meshing the surface, a quarter of the ultra-thin glass tempered pattern was selected to reduce the number of computational meshes and computation time. The fluid domain was meshed using an O-shaped grid and swept. The solid domain was meshed using an O-shaped grid that spread out to all four sides and swept within a single domain. A boundary layer was set for the fluid domain with a growth factor of 1.2 and three layers.

[0048] In step S4, a coupled calculation of the flow field, temperature field, and solid field is performed on the ultra-thin glass computational domain. The bottom surface of the glass plate is fixed, the stress field calculation is selected for the solid physics model, and the initial temperature of the glass is set to 953 K. The nozzle flow domain is set to the wall surface, the temperature is set to the actual inlet temperature, the inlet of the flow field region inside the nozzle is set to the velocity inlet, and the outlet of the flow field region at the junction of the nozzle and the glass plate is set to the pressure outlet. The calculation range is 1 / 4 of the ultra-thin tempered glass model, so symmetry constraints are set at the symmetric interfaces of the model.

[0049] In steps S5 and S6, a single calculation can simultaneously change the glass plate thickness h, the ratio of the jet height to the equivalent diameter of the nozzle bottom surface H / D, and the jet Reynolds number Re, reducing the number of calculations, simplifying the calculation difficulty and time, and at the same time testing the changes in thermal stress under different parameters, selecting the optimal solution, and improving the quenching efficiency of ultra-thin glass.

[0050] In step S7, the nozzle model shape is modified and the above steps are repeated. The results are analyzed to determine the strengths and weaknesses of each nozzle and to select the optimal solution for the optimal nozzle shape. This provides precise numerical values for ultra-thin tempered glass thermal stress simulation, improves the accuracy of stress simulation results, and allows selection of appropriate glass quenching optimization solutions, providing a basis for further research.

[0051] The present invention uses a glass plate vertically sprayed by a cylindrical nozzle with a single hole chamfer angle of 45° as the research object. A model is established in COMSOL software, with the upper area as the fluid domain and the bottom area as the solid domain made of quartz glass. The three-dimensional model of the glass plate is constructed as follows: Figure 2 shown.

[0052] Set the jet to air and enter it into the fluid domain material properties of COMSOL. According to the data, the changes of glass thermophysical parameters with temperature are shown in Table 1:

[0053] Temperature T(K) 298 373 473 573 673 773 873 <![CDATA[Specific heat capacity c p (J / (kg·K))]]> 721 838 946 1036 1084 1108 1146 Thermal conductivity λ (W / (m·K)) <![CDATA[ 1.4 ]]> <![CDATA[ 1.47 ]]> <![CDATA[ 1.55 ]]> <![CDATA[ 1.67 ]]> <![CDATA[ 1.84 ]]> 2.04 2.46 <![CDATA[Coefficient of thermal expansion α (× 10 -5 / K)]]> 1.037 1.0371 1.0375 1.0424 1.0908 1.5771 1.1380

[0054] According to Table 1, the specific heat capacity of glass c p , thermal conductivity λ and thermal expansion coefficient α will produce nonlinear changes with the increase of temperature. According to the data given in Table 1, the specific heat capacity c of glass is p The relationship between the thermal conductivity λ and the thermal expansion coefficient α and the temperature is fitted.

[0055] The fitting relationship between specific heat capacity and thermal conductivity is as follows:

[0056] c p =1200.45-1410.99e -0.00366T (1)

[0057] λ=1.271+0.045e 0.003T (2)

[0058] The fitting formula of the thermal expansion coefficient is as follows:

[0059]

[0060]

[0061] Enter the fitting curve into the material properties of the glass in COMSOL and enter the density of the glass as ρ = 2500 kg / m 3 , elastic modulus E = 71000 MPa and Poisson's ratio μ = 0.22.

[0062] After solid modeling, the model needs to be discretized into a mesh model, controlled by defining element properties and mesh generation. In finite element models, the number of node length calculations is directly related to the number of nodes. Mesh density affects computational accuracy; a higher mesh density increases the solution time. Therefore, it is important to control this density within the accuracy range to reduce computational time. For multi-field coupled analysis, higher mesh density is required for interfaces and fluid domains.

[0063] Because the ultra-thin glass tempering model is symmetrical about the XOZ plane and the YOZ plane, in order to reduce the number of computational grids and thus improve computational time and simulation efficiency, only 1 / 4 of the model needs to be built when building the model. The fluid domain is divided into "O"-shaped grids and swept, while the solid domain is spread to the four sides of the "O"-shaped grid within a single domain and swept. The boundary layer is set in the fluid domain, the growth factor is 1.2, and the number of layers is 3. The final refinement result is as follows: Figure 3 shown.

[0064] right Figure 2 and Figure 3 The model is subjected to boundary conditions. The solid field, flow field, and temperature field are coupled at the same time. The bottom surface of the glass plate is fixed. The stress field calculation is selected for the solid physics model, and the initial temperature of the glass is set to 953K. The nozzle flow area is set as the wall surface, the temperature is set to the actual inlet temperature, the inlet of the flow field area inside the nozzle is set as the velocity inlet, and the outlet of the flow field area at the junction of the nozzle and the glass plate is set as the pressure outlet.

[0065] The solver is set up. Because glass tempering generally occurs in a very short period of time, the stress of tempered glass is usually formed in about 3 seconds. Therefore, the study is set to transient, the calculation time is 3 seconds, the step size is 0.1 seconds, and the variable parameters are set to parametric sweep. The change value of h is set to 1.5 mm and 2 mm, the change value of the ratio of the jet height to the equivalent diameter of the nozzle bottom surface H / D is set to 0.2, and the jet Reynolds number Re is set to 8000 and 15000 for the single-hole nozzle model for calculation.

[0066] The calculation results are exported, and the center line on the central section is taken as the normal line when the real-time glass stress changes. The data are plotted as curves at 0.1s, 0.3s, 0.6s, 1s, 2s and 3s when the glass thickness h is 1.5mm and 2mm, the ratio of the jet height to the equivalent diameter of the nozzle bottom surface H / D = 0.2, and the jet Reynolds number Re is 8000 and 15000, as shown in the figure. Figure 4 shown.

[0067] according to Figure 5A double-sided schematic diagram of the glass forming process shows that the ultra-thin glass forming process is basically consistent with the theoretical diagram. The data curve also shows that ultra-thin glass, like ordinary glass, has the characteristic of the extreme stress point being at 1 / 3 of the thickness direction, which is difficult to achieve with other simulations. The calculation results of previous simulations by others are more consistent with the actual situation. Analysis shows that with the increase of Re, the trend of transient thermal stress changes basically does not change. The Reynolds number only changes the total amount of the final stress change. The larger the jet Reynolds number, the greater the stress amplitude and the better the effect. As h increases, the final amplitude of the stress curve increases, the stress gradient formation effect is better, and the change curve becomes more stable.

[0068] The features of the embodiments of the present invention are:

[0069] (1) The nozzle shape that can be selected can be cylindrical, truncated cone or other shapes. The nozzle can be simulated at any angle. Repeated experiments are conducted to select the jet quenching scheme suitable for the current working conditions.

[0070] (2) When calculating the thermal stress of glass during tempering, the glass will gradually transform from an elastoplastic body to a viscoelastic body, which will also have a significant impact on the residual stress results under stress relaxation. p The relationship between the thermal conductivity λ and the thermal expansion coefficient α and the temperature can more accurately calculate the thermal stress changes in the glass creep process.

[0071] (3) Because the ultra-thin glass tempering model is symmetrical about the XOZ plane and the YOZ plane, in order to reduce the number of computational grids and thus improve the computational time and simulation efficiency, only 1 / 4 of the model needs to be established when building the model.

[0072] (4) A single calculation can simultaneously change the glass plate thickness h, the ratio of the jet height to the equivalent diameter of the nozzle bottom surface H / D, and the jet Reynolds number Re, reducing the number of calculations, simplifying the calculation difficulty and time, and at the same time testing the changes in thermal stress under different parameters, selecting the optimal solution, and improving the quenching efficiency of ultra-thin glass.

[0073] (5) At the same time, within 3 seconds after the glass tempering is completed, the thermal stress distribution change line at a certain time can be randomly extracted to realize real-time stress calculation.

[0074] (6) It also provides accurate numerical values for the thermal stress simulation of ultra-thin tempered glass, improves the accuracy of stress simulation results, and selects appropriate glass quenching optimization schemes, providing solutions for further research in the future.

[0075] The above description of the preferred embodiments of the present invention is intended to serve as a guide. Based on the above description, relevant personnel are fully capable of making various changes and modifications without departing from the technical scope of this invention. The technical scope of this invention is not limited to the contents of the specification and must be determined according to the scope of the claims.

Claims

1. A method for simulating thermal stress during the tempering process of ultra-thin glass, characterized in that: The steps include: S1. Create an ultra-thin glass tempering model. Select a set of ultra-thin glass plates with vertical jets as stress simulation objects and establish a computational domain for the ultra-thin glass. The computational domain includes a fluid domain and a solid domain. The fluid domain includes the flow field area inside the nozzle and the flow field area at the junction of the nozzle and the glass plate. The solid domain is the solid field area of the glass plate. S2. Define material properties. After solid modeling, the model needs to be discretized into a grid model. By defining unit properties and grid generation control, first define the elastic modulus E and Poisson's ratio μ of the glass. Then set the flow field material to air, set the changes of the thermophysical parameters of the glass with temperature, and fit the specific heat capacity c of the glass. p The specific heat capacity c of glass is defined by the relationship between the thermal conductivity λ and the thermal expansion coefficient α as a function of temperature. p , thermal conductivity λ and thermal expansion coefficient α; S3. Mesh the ultra-thin glass model and its computational domain. Use common-node meshes at both solid and fluid interfaces. Based on the actual simulation environment, segment the solid and fluid domains of the ultra-thin glass model. Adjust the number of boundary cells and generate solid and fluid domain meshes, respectively. S4. Define the physical field, apply the same boundary conditions to the grid model, set the coupling of the solid field, flow field, and temperature field, fix the bottom surface of the glass plate, select the stress field calculation for the solid physics model, set the initial temperature of the glass, set the nozzle flow area around the wall, set the temperature to the actual inlet temperature, set the inlet of the flow field area inside the nozzle as the velocity inlet, and set the outlet of the flow field area at the junction of the nozzle and the glass plate as the pressure outlet; S5. Load the solver, load the physical field set in the model into the solver, set the variable parameters to parametric sweep, and calculate the thickness, the ratio of the jet height to the equivalent diameter of the nozzle bottom surface, and the jet Reynolds number of the single-hole nozzle model respectively; S6. Result Analysis: Analyze the simulation results of the previous solver. First, compare them with the theoretical research results of the common glass tempering process and the changes in thermal stress during glass forming. Then, analyze the forming effects of glass thermal stress under different parameters and select the optimal solution to improve the glass quenching efficiency. S7. Change the shape of the nozzle model and repeat the above steps until all calculations are completed. Through result analysis, the advantages and disadvantages of each nozzle, and research on different nozzle shapes, the optimal solution for the best nozzle shape is selected.

2. The method for simulating thermal stress during the tempering process of ultra-thin glass according to claim 1, characterized in that: In step S1, when simplifying the ultra-thin glass model, a 1 / 4 model is established when establishing the model, and the nozzle shape is selected. The nozzle can be simulated at any angle, and repeated experiments are performed to select an appropriate jet quenching scheme.

3. The method for simulating thermal stress during the tempering process of ultra-thin glass according to claim 2, characterized in that: In step S2, when calculating the thermal stress of the glass during tempering, the glass will gradually transform from an elastoplastic body to a viscoelastic body, which has a significant impact on the residual stress results under stress relaxation. p The relationship between the thermal conductivity λ and the thermal expansion coefficient α and the temperature can be used to more accurately calculate the thermal stress changes in the glass creep process.

4. The method for simulating thermal stress during the tempering process of ultra-thin glass according to claim 3, characterized in that: In step S3, when dividing the surface mesh, the fluid domain portion of 1 / 4 of the ultra-thin glass tempered pattern was selected and divided using an "O"-shaped mesh and swept. The solid domain was divided using an "O"-shaped mesh spread to the four sides within a single domain and swept. A boundary layer was set in the fluid domain, and the growth factor and number of layers were determined.

5. The method for simulating thermal stress during the tempering process of ultra-thin glass according to claim 4, characterized in that: In step S4, the flow field, temperature field, and solid field of the ultra-thin glass calculation domain are coupled and calculated. The bottom surface of the glass plate is fixed, the stress field calculation is selected for the solid physics model, the initial temperature of the glass is set, the nozzle flow domain is set as the wall surface, the temperature is set to the actual inlet temperature, the inlet of the flow field area inside the nozzle is set as the velocity inlet, and the outlet of the flow field area at the junction of the nozzle and the glass plate is set as the pressure outlet. At the same time, the calculation range is 1 / 4 of the ultra-thin tempered glass model, so symmetric constraints are set at the symmetric interfaces of the model.

6. The method for simulating thermal stress during the tempering process of ultra-thin glass according to claim 5, characterized in that: In steps S5 and S6, the thickness of the glass plate h, the ratio of the jet height to the nozzle diameter H / D, and the jet Reynolds number Re are changed simultaneously in a single calculation, thereby reducing the number of calculations, simplifying the calculation difficulty, and reducing the calculation time. At the same time, the changes in thermal stress under different parameters are tested, the optimal solution is selected, and the quenching efficiency of ultra-thin glass is improved.

7. The method for simulating thermal stress during the tempering process of ultra-thin glass according to claim 6, characterized in that: In step S7, the shape of the nozzle model is changed, and the above steps are repeated. The advantages and disadvantages of each nozzle are analyzed through the results, and the optimal solution of the best nozzle shape is selected, thereby obtaining the best quenching solution for the overall simulation of ultra-thin tempered glass.

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