Simulation analysis method and device for bottle performance

Abstract

The invention relates to a simulation analysis method and device for bottle performance. The simulation analysis device comprises a bottle blank wall thickness obtaining module, a bottle blank heating simulation module, a blow molding simulation module and a structure simulation module, and the bottle blank wall thickness obtaining module, the bottle blank heating simulation module and the structure simulation module are all associated with the blow molding simulation module; a bottle blank wall thickness acquisition module acquires continuous and non-uniform bottle blank wall thickness data of the bottle blank three-dimensional solid model; the bottle blank heating simulation module receives the heating simulation parameters and simulates the heating process of the bottle blank before blow molding to obtain continuous and non-uniform bottle blank temperature distribution data; the blow molding simulation module simulates a bottle blank blow molding process according to the bottle blank wall thickness data, the bottle blank temperature distribution data and the received blow molding simulation parameters to obtain a bottle simulation model; and the structure simulation module performs bottle performance simulation analysis on the bottle simulation model to obtain performance simulation data of the bottle simulation model. And more real bottle body wall thickness distribution data and bottle blank temperature distribution data can be obtained, and the performance of the bottle can be predicted and evaluated more accurately.

Description

Technical Field

[0001] The present invention relates to the technical field of blow molding manufacturing, and specifically to a method and device for simulating and analyzing the performance of bottles. Background Art

[0002] Hollow containers manufactured by blow molding, such as PET beverage bottles obtained by injection stretch blow molding, PP daily chemical product bottles obtained by extrusion blow molding, etc., generally need to be subjected to performance tests such as vertical loading (i.e., empty bottle top pressure and filling top pressure), dropping, air pressure resistance value (positive pressure or negative pressure), etc. During the bottle type development stage, if the results of the above performance tests do not meet the expectations, the bottle type appearance design and the mold cavity are modified, and then the performance test is carried out again. This process is repeated until the performance meets the requirements. For bottle types with complex shapes, the above process is likely to involve a lot of trial - and - error costs and consume a relatively long development time.

[0003] The prior art discloses a combined simulation method for the injection stretch blow molding process and strength analysis of beverage bottles based on ANSYS, including adaptively modifying the CDB file of the final mode formed by the simulation of the stretch blow molding of plastic containers based on ANSYS to make it suitable for quasi - static analysis. At the same time, the upper and lower pressure plates in the pressure testing machine model are created in ANSYS Classic, the position of the lower pressure plate is fixed, and the downward pressing speed of the upper pressure plate is set. Then the CDB file of the modified final mode is imported and combined with the upper and lower pressure plates to realize the combined simulation analysis of the mechanical properties of the stretch blow molding simulation and the modal file of the blowing result.

[0004] It has the following technical problems: The wall thickness data of the preform constructed in the 3D modeling software is difficult to conform to the actual wall thickness distribution data of the bottle body, and the influence of the preform temperature distribution on the bottle is not considered, resulting in difficulty in obtaining a relatively accurate pre - estimated value of the bottle performance subsequently, which is not conducive to obtaining accurate simulation analysis results. Summary of the Invention

[0005] Aiming at the problems existing in the prior art, the purpose of the present invention is to provide a method and device for simulating and analyzing the performance of bottles, which can obtain more realistic wall thickness distribution data of the bottle body and preform temperature distribution data, and then make a relatively accurate prediction and evaluation of the bottle performance.

[0006] In order to achieve the above purpose, the present invention adopts the following technical solutions: A device for simulating and analyzing the performance of bottles includes a preform wall thickness acquisition module, a preform heating simulation module, a blow molding simulation module, and a structure simulation module; the preform wall thickness acquisition module, the preform heating simulation module, and the structure simulation module are all associated with the blow molding simulation module. The preform wall thickness acquisition module is used to obtain continuous non - uniform preform wall thickness data of the preform three - dimensional solid model. The preform heating simulation module is used to receive heating simulation parameters, simulate the heating process of the preform before blow molding, and obtain continuous and non-uniform preform temperature distribution data; The blow molding simulation module is used to simulate the blow molding process of the preform according to the preform wall thickness data, the preform temperature distribution data, and the received blow molding simulation parameters, and obtain a bottle simulation model; The structure simulation module is used to perform bottle performance simulation analysis on the bottle simulation model to obtain performance simulation data of the bottle simulation model.

[0007] Further, the preform wall thickness acquisition module is associated with the preform heating simulation module. The preform heating simulation module receives the preform wall thickness data, and the preform heating simulation module simulates the heating process based on the received preform wall thickness data and heating simulation parameters.

[0008] Further, an optimization module is further included. The optimization module is associated with the structure simulation module, the blow molding simulation module, and / or the preform heating simulation module and / or the preform wall thickness acquisition module. Correspondingly, the optimization module obtains an optimization scheme based on the performance simulation data and / or the blow molding simulation parameters, the bottle simulation model and / or the heating simulation parameters, the preform temperature distribution data and / or the wall thickness data of the preform three-dimensional solid model, and the preform wall thickness data, and adjusts the blow molding simulation parameters and / or the heating simulation parameters and / or the wall thickness data of the preform three-dimensional solid model according to the optimization scheme.

[0009] A method for simulating and analyzing the performance of a bottle includes: S1. The preform wall thickness acquisition module obtains continuous and non-uniform preform wall thickness data; S2. Set heating simulation parameters in the preform heating simulation module, and simulate the heating process of the preform before blow molding based on the heating simulation parameters to obtain continuous and non-uniform preform temperature distribution data; S3. The blow molding simulation module receives the preform wall thickness data and the preform temperature distribution data, sets blow molding simulation parameters based on the preform wall thickness data and the preform temperature distribution data, and simulates the blow molding process of the preform based on the blow molding simulation parameters to obtain a bottle simulation model; S4. The structure simulation module receives the bottle simulation model, performs bottle performance simulation analysis on the bottle simulation model, and obtains performance simulation data of the bottle simulation model.

[0010] Further, step S1 includes: S11. The preform wall thickness acquisition module obtains the preform geometric model constructed in the three-dimensional construction module, or the preform wall thickness acquisition module receives the imported preform geometric model; S12. Set calculation parameters for preform wall thickness calculation in the preform wall thickness acquisition module based on the wall thickness data of the three-dimensional solid model; S13. In the preform wall thickness acquisition module, solve the preform geometric model based on the calculation parameters to obtain continuous and non-uniform preform wall thickness data; S14. Export the preform wall thickness data, or the preform wall thickness acquisition module sends the preform wall thickness data to the blow molding simulation module.

[0011] Further, step S2 includes: S21. The preform heating simulation module acquires the preform geometric model and the heating module geometric model constructed in the three-dimensional construction module, or the preform heating simulation module receives the imported preform geometric model and heating module geometric model; S22. Set the heating simulation parameters based on the preform geometric model and the heating module geometric model; S23. In the preform heating simulation module, perform a solution operation based on the heating simulation parameters to obtain the preform temperature distribution simulation result, that is, the continuous and non-uniform preform temperature distribution data after heating the preform; S24. Export the preform temperature distribution data, or the preform heating simulation module sends the preform temperature distribution data to the blow molding simulation module.

[0012] Further, step S2 further includes: The preform heating simulation module receives the preform wall thickness data of the preform wall thickness acquisition module, and simulates the heating process of the preform before blow molding based on the preform wall thickness data and the heating simulation parameters.

[0013] Further, step S3 includes: S31. The blow molding simulation module acquires the preform geometric model and the blow molding module geometric model constructed in the three-dimensional construction module, or the blow molding simulation module receives the imported preform geometric model and blow molding module geometric model; S32. The blow molding simulation module receives the preform wall thickness data and the preform temperature distribution data, and sets the blow molding simulation parameters in the blow molding simulation module according to the preform wall thickness data, the preform temperature distribution data, the preform geometric model, and the blow molding module geometric model; S33. In the blow molding simulation module, perform a solution operation based on the blow molding simulation parameters to obtain the bottle simulation model formed by simulated blow molding; S34. Export the bottle simulation model, or the blow molding simulation module sends the bottle simulation model to the structural simulation module.

[0014] Further, step S3 further includes: The structure evaluation module receives the bottle simulation model, and the structure evaluation module evaluates the closeness of the wall thickness distribution of the bottle simulation model to the wall thickness distribution of the actual bottle.

[0015] Further, it further includes: S5. The optimization module obtains an optimization solution based on the performance simulation data and / or blow molding simulation parameters, the bottle simulation model and / or the heating simulation parameters, the preform temperature distribution data and / or the wall thickness data of the three-dimensional solid model of the preform, and the wall thickness data of the preform, and adjusts the blow molding simulation parameters and / or the heating simulation parameters and / or the wall thickness data of the three-dimensional solid model of the preform according to the optimization solution.

[0016] Further, step S5 includes: S51. The optimization module receives the performance simulation data of the structural simulation module and / or the blow molding simulation parameters of the blow molding simulation module, the bottle simulation model and / or the heating simulation parameters of the preform heating simulation module, the preform temperature distribution data and / or the wall thickness data of the three-dimensional solid model of the preform, and the wall thickness data of the preform obtained by the preform wall thickness acquisition module as candidate parameters; S52. At least some of the performance simulation data and at least some of the blow molding simulation parameters in the candidate parameters are set as variable parameters, and the variable parameters are divided into independent variables and dependent variables according to the causality between them; S53. A series of different design independent variables are generated based on the independent variables, and a series of design dependent variables are obtained based on the solution operation of the design independent variables; S54. An optimization solution of the dependent variable corresponding to the independent variable is obtained based on the analysis of the design independent variables and the design dependent variables, and the blow molding simulation parameters and / or the heating simulation parameters and / or the wall thickness data of the three-dimensional solid model of the preform are adjusted according to the optimization solution.

[0017] Generally speaking, the present invention has at least the following partial advantages: The present invention uses the blow molding simulation module to receive the continuous non-uniform wall thickness data of the three-dimensional solid model of the preform obtained by the preform wall thickness acquisition module, and the continuous non-uniform preform temperature distribution data obtained by the preform heating simulation module based on the heating simulation parameters to simulate the heating process of the preform before blow molding, and then simulates the blow molding process of the preform to obtain a bottle simulation model closer to the actual situation. Furthermore, the structural simulation module performs bottle performance simulation analysis on the bottle simulation model to obtain more accurate performance simulation data of the bottle simulation model; applying the preform wall thickness data to the preform heating simulation module further improves the accuracy of the bottle simulation model and the performance simulation data. The optimization module provides an analysis of the influence of the independent variable on the dependent variable, realizes the control of the dependent variable through the optimization of the independent variable, and further realizes the optimization of the preform structure, the bottle shape structure, the heating parameters, and the blow molding parameters based on the simulation results. Description of the Drawings

[0018] Figure 1 It is a schematic structural diagram of the simulation analysis device of the present invention.

[0019] Figure 2 It is a schematic diagram of the evaluation method for the accuracy of the wall thickness distribution of the bottle in the blow molding simulation of the present invention. Detailed implementation manners

[0020] Since the physical test process is to blow the bottle first and then test the performance of the bottle, and in actual situations, the wall thickness of the preform, the temperature of the preform after heating, the wall thickness of the bottle after blowing, etc. are all continuous and non-uniformly distributed. In order to predict and evaluate certain performances of the bottle as accurately as possible, the simulation components establish a preform heating simulation module, a blow molding simulation module, and a structural simulation module with reference to the actual process. At the same time, a preform wall thickness acquisition module and an optimization module are established according to the requirements of the situation.

[0021] The following will further elaborate on the present invention in detail.

[0022] As Figure 1 shown, a simulation analysis device for the performance of a bottle includes a three-dimensional construction module, a preform wall thickness acquisition module, a preform heating simulation module, a blow molding simulation module, a structural simulation module, and a structural evaluation module. The preform wall thickness acquisition module, the preform heating simulation module, and the structural simulation module are all associated with the blow molding simulation module.

[0023] The three-dimensional construction module is used to construct a preform geometric model, a heating module geometric model, and a blow bottle module geometric model; The preform wall thickness acquisition module is used to obtain the continuous and non-uniform preform wall thickness data of the preform three-dimensional solid model, where the preform three-dimensional solid model is the preform geometric model constructed by the three-dimensional construction module or imported from the outside; The preform heating simulation module is used to receive heating simulation parameters and simulate the heating process of the preform before blow molding through the heating module geometric model to obtain continuous and non-uniform preform temperature distribution data closer to the actual situation; The blow molding simulation module is used to simulate the blow molding process of the preform through the blow bottle module geometric model according to the preform wall thickness data, preform temperature distribution data closer to the actual situation, and the received blow molding simulation parameters to obtain a more realistic bottle simulation model; The structural simulation module is used to perform bottle performance simulation analysis on the more realistic bottle simulation model to obtain more accurate performance simulation data of the bottle simulation model. In this embodiment, the performance simulation data includes the top pressure of the empty bottle, the filling top pressure, the drop deformation, the air pressure resistance value, etc. of the bottle. The continuous and non-uniform wall thickness of the bottle body is set in combination with the wall thickness distribution data of the bottle body obtained by the blow molding simulation module before, rather than simply setting a uniform wall thickness, so as to more accurately predict the data of the above performances.

[0024] Preferably, the preform wall thickness acquisition module is associated with the preform heating simulation module, and the preform heating simulation module receives the preform wall thickness data, so that the preform heating simulation module simulates the heating process based on the more realistic preform wall thickness data and obtains more realistic preform temperature distribution data.

[0025] The optimization module is associated with the structure simulation module, the blow molding simulation module, and / or the preform heating simulation module, and / or the preform wall thickness acquisition module. Correspondingly, the optimization module obtains an optimization solution based on the performance simulation data and / or the blow molding simulation parameters, the bottle simulation model and / or the heating simulation parameters, the preform temperature distribution data and / or the wall thickness data of the preform three-dimensional solid model, and the preform wall thickness data, and adjusts the blow molding simulation parameters and / or the heating simulation parameters and / or the wall thickness data of the preform three-dimensional solid model according to the optimization solution. The optimization module can either list a series of independent variables (or called input parameters, for example, some blow molding process parameters can be set as independent variables) and the corresponding dependent variables (or called output parameters, for example, the top pressure value of the bottle can be set as the dependent variable) obtained by solving for comparison, so as to compare a better set of independent variables; or perform a parameter correlation analysis on the independent variables and the dependent variables, so as to compare the degree and trend of influence of each independent variable on the dependent variable; or adjust the optimization independent variables according to the gap between the dependent variable and the expected value, so that the gap between the dependent variable and the expected value is continuously reduced until an acceptable level.

[0026] In implementation, the simulation analysis device further includes a structure evaluation module, which is associated with the blow molding simulation module, receives the bottle simulation model of the blow molding simulation module, and evaluates the closeness of the wall thickness distribution of the bottle simulation model to the wall thickness distribution of the actual bottle.

[0027] In implementation, "associated" means that there is a data transmission relationship between the two. Taking the association between the preform wall thickness acquisition module and the blow molding simulation module as an example, the association relationship between the preform wall thickness acquisition module and the blow molding simulation module includes the data transmission relationship of exporting the preform wall thickness data from the preform wall thickness acquisition module and then importing the preform wall thickness data into the blow molding simulation module, and also includes the data transmission relationship of the preform wall thickness acquisition module sending the data to the blow molding simulation module.

[0028] A simulation analysis method for the performance of a bottle, including: S1. The preform wall thickness acquisition module acquires continuous non-uniform preform wall thickness data; S2. Set heating simulation parameters in the preform heating simulation module, and simulate the heating process of the preform before blow molding based on the heating simulation parameters to obtain continuous non-uniform preform temperature distribution data; S3. The blow molding simulation module receives the preform wall thickness data and the preform temperature distribution data, sets blow molding simulation parameters based on the preform wall thickness data and the preform temperature distribution data, and simulates the blow molding process of the preform based on the blow molding simulation parameters to obtain a bottle simulation model; S4. The structure simulation module receives the bottle simulation model, performs a bottle performance simulation analysis on the bottle simulation model, and obtains the performance simulation data of the bottle simulation model.

[0029] Specifically, step S1 includes: S11. The preform wall thickness acquisition module acquires the preform geometric model constructed in the 3D construction module, or the preform wall thickness acquisition module receives the imported preform geometric model; S12. Set the calculation parameters for preform wall thickness calculation based on the wall thickness data of the 3D solid model in the preform wall thickness acquisition module; S13. Perform a solution operation on the preform geometric model based on the calculation parameters in the preform wall thickness acquisition module to obtain continuous non-uniform preform wall thickness data; S14. Export the preform wall thickness data, or the preform wall thickness acquisition module sends the preform wall thickness data to the blow molding simulation module.

[0030] For the blow molding simulation module established in this embodiment, since the material viscosity model selected requires the corresponding geometric model to be a 3D curved surface body rather than a 3D solid, the thickness of the 3D curved surface body needs to be set. The preform wall thickness acquisition module solves the continuous non-uniform preform wall thickness data based on the wall thickness data of the 3D solid model. In other embodiments, if the geometric model corresponding to the material viscosity model selected in the blow molding simulation module is a 3D solid, the continuous non-uniform preform wall thickness data of the preform 3D solid model obtained by the preform wall thickness acquisition module is used to construct the preform geometric model, and this preform geometric model is used for the blow molding simulation module and can also be used for the preform heating simulation module.

[0031] Through this step, relatively accurate bottle wall thickness distribution data can be obtained, so that a more realistic bottle simulation model can be obtained using the blow molding simulation module, which is beneficial to obtaining a more realistic simulation effect.

[0032] Analysis process of the preform wall thickness acquisition module: The acquisition of the preform wall thickness can be realized by analysis systems such as ANSYS POLYFLOW and ANSYS FLUENT MATERIALS PROCESSING in the ANSYS WORKBENCH workflow interface.

[0033] The specific analysis process includes: Step 1. Establish a preform geometric model in 3D drawing software and export it in a format that can be imported into ANSYS, such as the stp format. This preform geometric model is a 3D geometric model.

[0034] Step 2. Open the ANSYS WORKBENCH workflow interface and establish an ANSYS POLYFLOW analysis system.

[0035] Step 3: Open the geometry component in the ANSYS POLYFLOW analysis system and import the preform geometry model. Alternatively, construct the preform geometry model based on the 3D building blocks within ANSYS to replace importing from external sources. 3D drawing software within ANSYS, such as DISCOVERY, etc., serves as the 3D building blocks. Establish a DISCOVERY drawing component in the ANSYS WORKBENCH workflow interface, create a 3D geometry model within this DISCOVERY drawing component, and then connect the DISCOVERY drawing component to the geometry component of the ANSYS POLYFLOW analysis system in the ANSYS WORKBENCH workflow interface to complete the establishment of the 3D geometry model in the ANSYS POLYFLOW analysis system. Using this method can omit Step 1 and also omit the step of importing the 3D geometry model exported from external 3D drawing software into ANSYS POLYFLOW, which is more conducive to subsequent parametric optimization design of the geometry model. Preferably, perform appropriate processing on the 3D geometry model in the ANSYS POLYFLOW analysis system, such as naming each part of the geometry model separately for differentiation in the next step.

[0036] Step 4: Open the mesh component in the ANSYS POLYFLOW analysis system and perform mesh division on the 3D geometry model. When dividing the mesh, mainly use hexahedral meshes. Since a conventional preform is a tubular structure with one end open and the other end closed, select either the inner or outer surface as the source term and target term to establish a mapping relationship for dividing the hexahedral mesh. Preferably, appropriately refine and encrypt the mesh in local areas with complex geometric features, such as the bottom and arc transition regions of the preform, to avoid shape distortion, and name each part of the 3D geometry model appropriately for differentiation in the next step.

[0037] Step 5: Open the settings component in the ANSYS POLYFLOW analysis system and enter the POLYDATA interface. In this interface, perform settings in aspects such as selecting steady-state analysis, establishing a post-processing sub-task for wall thickness calculation, dimension unit system, and output result data.

[0038] Step 6: Use the solution component in the ANSYS POLYFLOW analysis system to perform solution operations. Preferably, select to set parallel multi-core solution to improve the operation efficiency.

[0039] Step 7: After the operation is completed, open the result component in the ANSYS POLYFLOW analysis system and enter the CFXPOST interface. In this interface, export and generate a file storing the wall thickness distribution data of the preform, name this file appropriately, and specify to store it in an appropriate path for use in subsequent preform heating simulation modules and blow molding simulation modules.

[0040] Step S2 includes: S21. The preform heating simulation module obtains the preform geometric model and the heating module geometric model in the three-dimensional construction module, or the preform heating simulation module receives the imported preform geometric model and heating module geometric model; S22. Set the heating simulation parameters based on the preform geometric model and the heating module geometric model; S23. Perform a solution operation in the preform heating simulation module based on the heating simulation parameters to obtain the preform temperature distribution simulation result, that is, the continuous non-uniform preform temperature distribution data after the preform is heated; S24. Export the preform temperature distribution data, or the preform heating simulation module sends the preform temperature distribution data to the blow molding simulation module.

[0041] Specifically, the analysis process of the preform heating simulation module: The heating simulation can be performed in ANSYS MECHANICAL, ANSYS FLUENT, ABAQUS, etc. The actual preform heating machine generally uses quartz tubes to irradiate and heat. In this process, heat transfer mainly occurs through radiation, followed by natural convection heat transfer of air, and almost no contact heat transfer. Preferably, the ANSYS MECHANICAL TRANSIENT THERMAL transient thermal analysis system is used to perform the preform heating simulation.

[0042] The specific analysis process includes: Step 1. Establish the three-dimensional geometric models of the preform, heating element, heat insulation baffle, etc. in a three-dimensional drawing software, and export them in a format that can be imported into ANSYS, such as the stp format.

[0043] Step 2. Open the ANSYS WORKBENCH workflow interface and establish the ANSYS MECHANICAL TRANSIENT THERMAL analysis system.

[0044] Step 3. Open the geometric structure component in the ANSYS MECHANICAL TRANSIENT THERMAL analysis system and import the three-dimensional geometric model exported in Step 1. Preferably, perform appropriate processing on the three-dimensional geometric model, such as naming each part of the three-dimensional geometric model appropriately for differentiation in the next step. In this step, the three-dimensional geometric model can also be constructed based on the three-dimensional construction module in the same way as in Step 3 of Step S1.

[0045] Step 4: Open the mesh component in the ANSYS MECHANICAL TRANSIENT THERMAL analysis system and perform mesh division on the three-dimensional geometric model. Preferably, for local areas with complex modeling features, the mesh should be appropriately refined to avoid shape distortion, and each part of the geometric model should be appropriately named to distinguish them in the next step.

[0046] Step 5: Since the mesh component, setup component, solution component, and result component in the ANSYS MECHANICAL TRANSIENT THERMAL analysis system are in the same MECHANICAL interface, operations such as mesh division, boundary condition setting, solution calculation, and result viewing can be performed. After the mesh division in the previous step is completed, continue to set the boundary conditions, for example, perform settings in aspects such as material specification for each object, radiation heat transfer parameters of the heating element, convective heat transfer parameters of air, initial temperature of the preform, and heating duration.

[0047] Step 6: Perform solution calculation in the MECHANICAL interface, and then wait for the calculation to end; Step 7: After the calculation in Step 6 is completed, view the temperature distribution of the preform in the MECHANICAL interface. If the temperature distribution of the preform does not meet the expected requirements, it is necessary to return to Step 5 above to appropriately modify parameters such as the heating duration and parameters of the heating element, and then perform the solution calculation again in Step 6, and then view the results again. Repeat this cycle until the temperature distribution of the preform meets the expected requirements.

[0048] Step 8: Export the preform temperature distribution data, appropriately name the file and specify the storage path for use in the subsequent blow molding simulation module.

[0049] Step S2 further includes: The preform heating simulation module receives the preform wall thickness data from the preform wall thickness acquisition module, and simulates the heating process of the preform before blow molding based on the preform wall thickness data and heating simulation parameters. Enabling the preform heating simulation module to simulate the heating process based on more realistic preform wall thickness data can obtain more realistic preform temperature distribution data, which is conducive to obtaining more accurate simulation results in the subsequent steps.

[0050] Step S3 includes: S31: The blow molding simulation module obtains the preform geometric model and blow molding module geometric model in the three-dimensional construction module, or the blow molding simulation module receives the imported preform geometric model and blow molding module geometric model; S32: The blow molding simulation module receives the preform wall thickness data and preform temperature distribution data, and sets the blow molding simulation parameters in the blow molding simulation module according to the preform wall thickness data, preform temperature distribution data, preform geometric model, and blow molding module geometric model. S33. Perform a solution operation based on the blow molding simulation parameters in the blow molding simulation module to obtain a bottle simulation model formed by simulated blow molding. S34. Export the bottle simulation model, or the blow molding simulation module sends the bottle simulation model to the structural simulation module.

[0051] Analysis process of the blow molding simulation module: Software for blow molding simulation includes, for example, ANSYS POLYFLOW, ANSYS FLUENT MATERIALS PROCESSING, ABAQUS, B-SIM, T-SIM, etc. In this embodiment, ANSYS POLYFLOW is selected to establish the blow molding simulation module.

[0052] The specific analysis process includes: Step 1. Establish three-dimensional geometric models of the preform, stretching rod, bottle, blow molding die, etc. in three-dimensional drawing software and export them in a format that can be imported into ANSYS, such as the stp format.

[0053] Step 2. Open the ANSYS WORKBENCH workflow interface to establish an ANSYS POLYFLOW analysis system.

[0054] Step 3. Open the geometric structure component in the ANSYS POLYFLOW analysis system and import the three-dimensional geometric model exported in Step 1. The K-BKZ material model can comprehensively describe the characteristic behaviors exhibited by the PET material during blow molding. Select the K-BKZ material model as the material model for the three-dimensional geometric model of the preform and the three-dimensional geometric model of the bottle, extract the surface curves of the three-dimensional geometric model of the preform and the three-dimensional geometric model of the bottle, and establish shell meshes to adapt to the K-BKZ material model. Preferably, perform appropriate processing on the three-dimensional geometric model, and name each part of the three-dimensional geometric model appropriately for differentiation in the next step. In this step, the three-dimensional geometric model can also be constructed based on the three-dimensional building blocks in the same way as in Step 3 of Step S1.

[0055] Step 4. Open the mesh component in the ANSYS POLYFLOW analysis system and perform mesh division on the three-dimensional geometric model. Since the three-dimensional geometric model obtained after the previous step is a curved surface, quadrilateral meshes are mainly used for mesh division. Preferably, appropriately refine and encrypt the meshes in the local areas with complex modeling features to avoid shape distortion, and name each part of the three-dimensional geometric model appropriately for differentiation in the next step.

[0056] Step 5: Open the settings component in the ANSYS POLYFLOW analysis system, enter the POLYDATA interface, and perform the following settings in this interface: Select transient analysis, blow molding process parameters (such as blow molding pressure, blow molding time, stretching rod speed, preform heating temperature (import the preform temperature distribution data exported from the preform heating simulation module to set the continuous non-uniform temperature distribution of the preform), mold temperature, etc.), select the K-BKZ material model, PET material parameters, preform wall thickness (import the preform wall thickness distribution data exported from the preform wall thickness acquisition module to set the continuous non-uniform wall thickness distribution of the preform), the motion states of the preform and the mold, the contact boundary and heat transfer coefficient between the preform and the mold, mesh refinement and mesh redivision during the blowing deformation process of the preform, dimension unit system, output result data (such as wall thickness distribution, draw ratio, etc.).

[0057] Step 6: Use the solution component in the ANSYS POLYFLOW analysis system to perform the solution operation. Preferably, select to set parallel multi-core solution to improve the operation efficiency.

[0058] Step 7: After the operation in Step 6 is completed, open the result component in the ANSYS POLYFLOW analysis system, enter the CFX POST interface, and in this interface, you can: Check whether the preform is blown into a full bottle, check the wall thickness distribution of the bottle after blow molding, check the draw ratio distribution of the bottle, etc. If the preform is not blown into a full bottle or the wall thickness distribution does not meet the expected requirements, it is necessary to return to Step 5 to appropriately modify the blow molding process parameters and then perform the re-solution operation in Step 6, and then re-check the results. Repeat this cycle until the preform is blown into a full bottle and the wall thickness distribution meets the expected requirements. This process can be combined with the ANSYS DESIGNXPLORER module or OPTISLANG module in the ANSYS WORKBENCH workflow interface to perform experimental design, parameter correlation analysis, optimization, etc., and perform qualitative and quantitative analysis and optimization of the blow molding process parameters based on the wall thickness distribution of the bottle.

[0059] Step 8: After obtaining the bottle wall thickness distribution that meets the expected requirements, export the data of the bottle wall thickness distribution in the CFX POST interface, such as exporting it in the csv table format, so as to import it into the structural simulation module later. If both the ANSYS POLYFLOW analysis system and the structural simulation module are established in the ANSYS WORKBENCH workflow interface, the ANSYS POLYFLOW analysis system can be connected to the structural simulation module, thus omitting the steps of exporting the bottle wall thickness distribution data from the ANSYS POLYFLOW analysis system and then importing it into the structural simulation module.

[0060] Step S3 further includes: The structure evaluation module receives the bottle simulation model, and evaluates the closeness of the wall thickness distribution of the bottle simulation model to that of the actual bottle.

[0061] As Figure 2 shown, with the axial height of the bottle body as the abscissa and the average wall thickness along the axial height of the bottle body as the ordinate, a wall thickness distribution curve is plotted. That is, at a certain height position, the average wall thickness in the circumferential direction at that height is measured around one week. By measuring the average wall thickness at different height positions, this curve can be obtained. The denser the measurement of the average wall thickness at different height positions along the axial direction of the bottle body, the smoother the curve. The smoother the curve, the more beneficial it is to improve the accuracy of subsequent evaluation, that is, increasing the number of sampling points to improve the accuracy.

[0062] Taking the wall thickness distribution curve of the actually detected bottle as a reference, calculate the area A3 of the overlapping part of the areas A1 and A2 formed by the wall thickness distribution curve of the blow molding simulation bottle and the wall thickness distribution curve of the actually detected bottle with the abscissa respectively. Divide A3 by the area A2 formed by the wall thickness distribution curve of the actually detected bottle and the abscissa, and a percentage value will be obtained. This value does not exceed 100%. The closer this value is to 100%, the higher the coincidence degree of the two curves, indicating that the wall thickness distribution of the blow molding simulation bottle is closer to the actual situation, that is, the higher the accuracy of the blow molding simulation. By comparing the wall thickness distribution curve of the blow molding simulation bottle and the wall thickness distribution curve of the actually detected bottle, the structure evaluation module can evaluate the closeness of the wall thickness distribution of the blow molding simulation bottle to that of the actually detected bottle.

[0063] This evaluation method can also be used to evaluate the closeness between the wall thickness distribution of the actually detected bottle and the wall thickness distribution of the given standard bottle.

[0064] Analysis process of the structure simulation module: Structural simulation mainly includes static simulation analysis and dynamic simulation analysis, etc. The processes of testing the top pressure, drop, and air pressure resistance values of the bottle are processes that will undergo large deformations in a short time, and it is suitable to use dynamic simulation analysis software to perform the simulation of the above performances. Dynamic simulation software includes, for example, ANSYS LS-DYNA, ABAQUS, etc. Since the aforementioned blow molding simulation module is established based on ANSYS POLYFLOW, considering data compatibility and transmission, preferably, the structure simulation module is established based on ANSYS LS-DYNA.

[0065] Specific analysis process: (Top pressure performance simulation) Step 1, export the three-dimensional geometric model of the bottle established using three-dimensional drawing software to a format that can be imported into ANSYS, such as the stp format.

[0066] Step 2: Open the ANSYS WORKBENCH workflow interface, establish the ANSYS LS-DYNA analysis system, open the engineering material component in the ANSYS LS-DYNA analysis system, establish the material models of the substances involved in the geometric model (such as PET material, water, air, etc.), and set their respective specific material parameters, such as density, yield strength, elastic modulus, Poisson's ratio, tangent modulus, etc.

[0067] Step 3: Open the geometric structure component in the ANSYS LS-DYNA analysis system, import the three-dimensional geometric model exported in Step 1, extract the surface curves of the three-dimensional geometric model of the bottle for subsequent calling of the blow molding simulation module to solve the obtained wall thickness distribution data of the bottle body to set the wall thickness of the bottle, add a pressing plate above the bottle to apply a vertically downward force on the bottle, add a support plate below the bottle to support the bottom of the bottle, add geometric bodies representing the regions of liquid and gas inside the bottle respectively (if it is a simulation to predict the top pressure performance of an empty bottle, it is not required), and appropriately name each part of the three-dimensional geometric model for distinction in the next step. In this step, the three-dimensional geometric model can also be constructed based on the three-dimensional building blocks in the same way as in Step 3 of Step S1.

[0068] Step 4: Open the mesh component in the ANSYS LS-DYNA analysis system, enter the MECHANICAL interface, and mesh the three-dimensional geometric model. Preferably, since the three-dimensional geometric model of the bottle obtained in the previous step is a surface, quadrilateral meshes are mainly used for meshing, and for other three-dimensional geometric models that are solids, hexahedral meshes are mainly used. Preferably, for local areas with complex modeling features, the meshes should be appropriately refined to avoid shape distortion, and each part of the three-dimensional geometric model should be appropriately named for use when setting boundary conditions later.

[0069] Step 5: Since the mesh component, setting component, solution component, and result component in the ANSYS LS-DYNA analysis system are in the same MECHANICAL interface, operations such as meshing, boundary condition setting, solution calculation, and result viewing can be performed. After the mesh division in the previous step, continue to set the boundary conditions, such as: specifying the materials of each object, specifying the wall thickness of the bottle (importing the wall thickness distribution result obtained by solving the blow molding simulation module and setting it on the three-dimensional geometric model of the bottle, and the wall thickness of the bottle is similar to the continuous non-uniform distribution in reality), the fluid-structure coupling state between the bottle and the internal liquid and gas (if it is a simulation to predict the top pressure performance of an empty bottle, it is not required), the contact state between the bottle and the pressing plate and the support plate, the contact friction coefficient, the displacement of the pressing plate, the fixed constraint of the support plate, the direction of gravity, etc.

[0070] Step 6, perform the solution operation in the MECHANICAL interface. Preferably, select parallel multi-core solution to improve the operation efficiency.

[0071] Step 7, after the operation in Step 6 is completed, view the results in the MECHANICAL interface. The change curve of the top pressure force, bottle deformation, bottle body stress and other results can be viewed. If the peak value of the change curve of the top pressure force (i.e., the maximum vertical load that the bottle can withstand) does not meet the expected requirements, it is necessary to return to Step 1 of Step S3 to appropriately modify the bottle shape and blow molding die. Then, after obtaining the required bottle wall thickness distribution through the blow molding simulation module again, perform the above processes from Step 3 to Step 6, and then view the results again. Repeat this cycle until the peak value of the change curve of the top pressure force (i.e., the maximum vertical load that the bottle can withstand) meets the expected requirements. This process can be combined with the ANSYS DESIGNXPLORER module or OPTISLANG module in the ANSYS WORKBENCH workflow interface to perform experimental design, parameter correlation analysis, optimization, etc., and perform qualitative and quantitative analysis and optimization on certain design parameters or certain blow molding process parameters of the bottle regarding the peak value of the top pressure force.

[0072] The simulation prediction analysis process for the drop and air pressure resistance performance is roughly the same as the above simulation prediction analysis process for the top pressure performance, mainly with differences in Step 3, Step 5 and Step 7.

[0073] Differences in the simulation prediction analysis process for the drop performance: When processing the three-dimensional geometric model in Step 3, in addition to extracting the bottle surface curve and adding geometric bodies representing the liquid and gas regions inside the bottle respectively, a flat plate needs to be added to represent the ground; When setting the boundary conditions in Step 5, it is necessary to perform the following settings: material specification of each object, bottle wall thickness specification, fluid-structure coupling state between the bottle and the internal liquid and gas, fixed constraint of the floor, gravity direction, distance between the bottle and the floor (i.e., the height from which the bottle drops), angle between the bottle and the floor (i.e., the attitude at which the bottle drops), initial velocity of the bottle, etc.; When viewing the results in Step 7, check whether the bottle is cracked or exploded after dropping and whether the bottle can roughly return to its original state after deformation.

[0074] Differences in the simulation prediction analysis process for the air pressure resistance performance: When processing the three-dimensional geometric model in Step 3, in addition to extracting the bottle surface curve, a support plate needs to be added below the bottle; When setting boundary conditions in Step 5, the following settings need to be carried out: material specification of each object, specification of the bottle wall thickness, fixed constraints of the support plate, direction of gravity, contact state between the bottle and the support plate, change amount of the internal air pressure of the bottle (if negative pressure simulation is carried out, the air pressure decreases; if positive pressure simulation is carried out, the air pressure increases, and the change of air pressure can be controlled by setting the volume flow rate or mass flow rate of the gas inside the bottle per unit time), etc. When viewing the results in Step 7, if negative pressure simulation is carried out, mainly check the reduction amount of the internal volume of the bottle body at the moment when the bottle yield mutation is reached; if positive pressure simulation is carried out, mainly check the maximum air pressure value inside the bottle body during the process of the bottle bursting.

[0075] There is also an optimization process S5, including: The optimization module obtains an optimization plan based on performance simulation data and / or blow molding simulation parameters, bottle simulation models and / or heating simulation parameters, preform temperature distribution data and / or wall thickness data of the preform three-dimensional solid model, and preform wall thickness data, and adjusts the blow molding simulation parameters and / or heating simulation parameters and / or wall thickness data of the preform three-dimensional solid model according to the optimization plan.

[0076] Specifically, Step S5 includes: S51. The optimization module receives the performance simulation data of the structural simulation module and / or the blow molding simulation parameters of the blow molding simulation module, bottle simulation models and / or heating simulation parameters of the preform heating simulation module, preform temperature distribution data and / or wall thickness data of the preform three-dimensional solid model, and preform wall thickness data of the preform wall thickness acquisition module as candidate parameters; S52. At least some of the performance simulation data and at least some of the blow molding simulation parameters in the candidate parameters are set as variable parameters, and the variable parameters are divided into independent variables and dependent variables according to the causality between them; S53. Generate a series of different design independent variables based on the independent variables, and obtain a series of design dependent variables through the solution operation based on the design independent variables; S54. Analyze and obtain an optimization plan for the dependent variable corresponding to the independent variable based on the design independent variables and design dependent variables, and adjust the blow molding simulation parameters and / or heating simulation parameters and / or wall thickness data of the preform three-dimensional solid model according to the optimization plan.

[0077] Analysis process of the optimization module: Since the previous multiple modules are all carried out by establishing analysis systems separately in the ANSYS WORKBENCH workflow interface, the ANSYS DESIGNXPLORER module or OPTISLANG module in the ANSYS WORKBENCH workflow interface has functions such as experimental design, sensitivity analysis, and optimization. Preferably, the ANSYS DESIGNXPLORER module or OPTISLANG module is used as the optimization module.

[0078] Specific analysis process: (taking DESIGNXPLORER module as an example) Step 1. In the aforementioned simulation module, the parameters and data involved are used as candidate parameters. The candidate parameters to be studied are set as variable parameters, such as certain process parameters in the blow molding simulation module, certain performance result data in the structural simulation module, etc. Since there is causality between the parameters, the parameters set as variable parameters will be automatically divided into input parameters (independent variables) and output parameters (dependent variables) by the optimization module.

[0079] Step 2: Add a series of independent variables with different values ​​as design independent variables. You can enter the design independent variables yourself, or you can use the DESIGN OF EXPERIMENTS (DOE) function to enter the design independent variables.

[0080] Step 3: Solve the design independent variables to obtain a series of design dependent variables. Use the PARAMETERSCORRELATION tool (i.e. parameter correlation tool) to analyze the influence and influence trend of multiple independent variables on the dependent variables, so as to focus on the important independent variables. Step 4. After analyzing the parameter correlation, you can use the RESPONSE SURFACE tool (i.e., response surface tool) to create a response surface diagram of a dependent variable with respect to the changes in certain independent variables, and obtain the changing trend, maximum or minimum value of the dependent variable, etc.

[0081] Step 5. After screening out important independent variables and understanding the response surface of the dependent variable, use the RESPONSESURFACE OPTIMIZATION tool or the DIRECTOPTIMIZATION tool (i.e., response surface optimization tool or direct optimization tool) to optimize the independent variables so as to improve the dependent variable.

[0082] This embodiment also provides a method for evaluating the degree of proximity between the structural performance simulation and the actual tested bottle performance (ie, a method for evaluating the accuracy of the structural performance simulation results).

[0083] Since the performance detections such as the top pressure and air pressure resistance values are generally single data results, the relative error between the simulation value and the detection value can be used to evaluate.

[0084] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A simulation analysis device for bottle performance, characterized in that: It includes a preform wall thickness acquisition module, a preform heating simulation module, a blow molding simulation module and a structure simulation module, and the preform wall thickness acquisition module, the preform heating simulation module and the structure simulation module are all associated with the blow molding simulation module; The preform wall thickness acquisition module is used to acquire continuous non-uniform preform wall thickness data of the preform three-dimensional solid model; The preform heating simulation module is used to receive heating simulation parameters, simulate the heating process of the preform before blow molding, and obtain continuous non-uniform preform temperature distribution data; The blow molding simulation module is used to simulate the blow molding process of the preform according to the wall thickness data of the preform, the temperature distribution data of the preform and the received blow molding simulation parameters to obtain a bottle simulation model; The structure simulation module is used to perform bottle performance simulation analysis on the bottle simulation model to obtain performance simulation data of the bottle simulation model.

2. The simulation analysis device according to claim 1, characterized in that: The preform wall thickness acquisition module is associated with the preform heating simulation module, the preform heating simulation module receives the preform wall thickness data, and the preform heating simulation module simulates the heating process based on the received preform wall thickness data and heating simulation parameters.

3. The simulation analysis device according to claim 1, characterized in that: It also includes an optimization module, which is associated with the structural simulation module, the blow molding simulation module and / or the bottle blank heating simulation module and / or the bottle blank wall thickness acquisition module. Accordingly, the optimization module obtains an optimization plan based on the performance simulation data and / or the blow molding simulation parameters, the bottle simulation model and / or the heating simulation parameters, the bottle blank temperature distribution data and / or the wall thickness data of the bottle blank three-dimensional solid model, and the bottle blank wall thickness data, and adjusts the blow molding simulation parameters and / or the heating simulation parameters and / or the wall thickness data of the bottle blank three-dimensional solid model according to the optimization plan.

4. A simulation analysis method for bottle performance, characterized in that: The simulation analysis device according to any one of claims 1 to 3 comprises: S1, a preform wall thickness acquisition module acquires continuous non-uniform preform wall thickness data; S2. Setting heating simulation parameters in the preform heating simulation module, simulating the heating process of the preform before blow molding based on the heating simulation parameters, and obtaining continuous non-uniform preform temperature distribution data; S3, the blow molding simulation module receives the bottle preform wall thickness data and the bottle preform temperature distribution data, sets the blow molding simulation parameters based on the bottle preform wall thickness data and the bottle preform temperature distribution data, simulates the blow molding process of the bottle preform based on the blow molding simulation parameters, and obtains a bottle simulation model; S4. The structure simulation module receives the bottle simulation model, performs bottle performance simulation analysis on the bottle simulation model, and obtains performance simulation data of the bottle simulation model.

5. The simulation analysis method according to claim 4, characterized in that: Step S1 includes: S11, the preform wall thickness acquisition module acquires the preform geometric model constructed in the three-dimensional construction module, or the preform wall thickness acquisition module receives the imported preform geometric model; S12, in a preform wall thickness acquisition module, setting calculation parameters for calculating the preform wall thickness based on the wall thickness data of the three-dimensional solid model; S13, in a preform wall thickness acquisition module, solving a preform geometric model based on calculation parameters to obtain continuous non-uniform preform wall thickness data; S14, exporting the preform wall thickness data, or the preform wall thickness acquisition module sends the preform wall thickness data to the blow molding simulation module.

6. The simulation analysis method according to claim 4, characterized in that: Step S2 includes: S21, the preform heating simulation module obtains the preform geometric model and the heating module geometric model constructed in the three-dimensional construction module, or the preform heating simulation module receives the imported preform geometric model and the heating module geometric model; S22, setting heating simulation parameters based on the preform geometric model and the heating module geometric model; S23, performing a solution operation based on the heating simulation parameters in the preform heating simulation module to obtain a simulation result of the temperature distribution of the preform, that is, continuous non-uniform temperature distribution data of the preform after heating; S24, exporting the preform temperature distribution data, or the preform heating simulation module sends the preform temperature distribution data to the blow molding simulation module.

7. The simulation analysis method according to claim 4, characterized in that: Step S2 also includes: the preform heating simulation module receives the preform wall thickness data from the preform wall thickness acquisition module, and simulates the heating process of the preform before blow molding based on the preform wall thickness data and the heating simulation parameters.

8. The simulation analysis method according to claim 4, characterized in that: Step S3 includes: S31, the blow molding simulation module obtains the preform geometric model and the blowing module geometric model constructed in the three-dimensional construction module, or the blow molding simulation module receives the imported preform geometric model and the blowing module geometric model; S32, the blow molding simulation module receives the preform wall thickness data and the preform temperature distribution data, and sets the blow molding simulation parameters in the blow molding simulation module according to the preform wall thickness data, the preform temperature distribution data, the preform geometric model and the blow molding module geometric model; S33, performing a solution operation based on the blow molding simulation parameters in the blow molding simulation module to obtain a bottle simulation model formed by simulating blow molding; S34, exporting the bottle simulation model, or the blow molding simulation module sends the bottle simulation model to the structure simulation module.

9. The simulation analysis method according to claim 4, characterized in that: Step S3 also includes: The structure evaluation module receives the bottle simulation model, and the structure evaluation module evaluates the degree of closeness between the wall thickness distribution of the bottle simulation model and the wall thickness distribution of the actual bottle.

10. The simulation analysis method according to claim 4, characterized in that: Also includes: S5. The optimization module obtains an optimization scheme based on the performance simulation data and / or blow molding simulation parameters, the bottle simulation model and / or heating simulation parameters, the preform temperature distribution data and / or the wall thickness data of the preform three-dimensional solid model, and the preform wall thickness data, and adjusts the blow molding simulation parameters and / or heating simulation parameters and / or the wall thickness data of the preform three-dimensional solid model according to the optimization scheme.

11. The simulation analysis method according to claim 10, characterized in that: Step S5 includes: S51, the optimization module receives the performance simulation data of the structure simulation module and / or the blow molding simulation parameters of the blow molding simulation module, the bottle simulation model and / or the heating simulation parameters of the preform heating simulation module, the preform temperature distribution data and / or the wall thickness data of the preform three-dimensional solid model, and the preform wall thickness data of the preform wall thickness acquisition module as candidate parameters; S52, at least part of the performance simulation data and at least part of the blow molding simulation parameters in the candidate parameters are set as variable parameters, and the variable parameters are divided into independent variables and dependent variables according to the causality between them; S53, generating a series of different design independent variables based on the independent variables, and obtaining a series of design dependent variables based on the solution operation of the design independent variables; S54, obtaining an optimization scheme of the dependent variables corresponding to the independent variables based on the analysis of the design independent variables and the design dependent variables, and adjusting the blow molding simulation parameters and / or the heating simulation parameters and / or the wall thickness data of the three-dimensional solid model of the preform according to the optimization scheme.

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