Simulation analysis method and system for buffer air column bag, terminal and storage medium

Abstract

The present application relates to the technical field of mechanical data simulation, and specifically provides a cushion air column bag simulation analysis method, system, terminal and storage medium, comprising: obtaining nominal strain generated by a sampling area of an air column bag in an inflation process, and saving the nominal strain and the sampling area as standard data; obtaining a stress-strain curve of air column bag material in a stretching process, and a corresponding deformation variable when the nominal strain in the standard data is reached, and saving the deformation variable as a material deformation variable of the sampling area; constructing an air column bag finite element grid model from the stress-strain curve and the material deformation variable of the sampling area, and performing simulation analysis based on the air column bag finite element grid model. The present application can improve the simulation analysis precision of the cushion air column bag, quickly identify defects in the air column bag design scheme, shorten the research and development cycle, and avoid quality problems after delivery.

Description

Technical Field

[0001] This invention belongs to the field of mechanical data simulation technology, specifically relating to a simulation analysis method, system, terminal, and storage medium for a buffer air column bag. Background Technology

[0002] Air column bags are a type of cushioning material, often used for packaging large equipment to prevent damage during transport. Designing air column bags requires modeling and mechanical data simulation analysis to verify the design's rationality. For example, air column bags can be treated as equivalent to EPE (Expanded Polyethylene). A cushioning curve is obtained through experiments using air column bags of a certain thickness and area. Then, based on the obtained cushioning curve and the actual product's weight, volume, and drop height, the required air column bag area and equivalent thickness for protection are calculated.

[0003] However, if you take countless small pieces of EPE from a block of EPE with the same density, the performance curve of each small piece of EPE will be consistent, indicating that EPE material is homogeneous and can be considered isotropic. In contrast, an air column bag consists of air chambers, thermoplastic seals, and corners. It is not a homogeneous material, and its buffering curve varies. Modeling and simulating an air column bag as equivalent to EPE suffers from insufficient accuracy. Summary of the Invention

[0004] To address the aforementioned shortcomings of existing technologies, this invention provides a method, system, terminal, and storage medium for simulating and analyzing buffer air column bags, thereby resolving the aforementioned technical problems.

[0005] In a first aspect, the present invention provides a simulation analysis method for a buffer air column bag, comprising: Obtain the nominal strain generated in the sampling area of ​​the air column bag during the inflation process, and save the nominal strain and the sampling area as standard data; Obtain the stress-strain curve of the air column bag material during the tensile process, and the deformation corresponding to the nominal strain in the standard data, and save the deformation as the material deformation of the sampling area; A finite element mesh model of an air column bag is constructed using the stress-strain curve and the material deformation of the sampling area, and simulation analysis is performed based on the finite element mesh model of the air column bag.

[0006] In an optional implementation, the nominal strain generated in the sampling area of ​​the air column bag during the inflation process is obtained, and the nominal strain and the sampling area are saved as standard data, including: The material thickness of the air column bag is obtained, and matching standard data is retrieved from the database based on the material thickness.

[0007] In one optional implementation, the sampling area includes an edge longitudinal sampling area, an edge transverse sampling area, a center longitudinal sampling area, and a center transverse sampling area.

[0008] In an optional embodiment, the sampling area is covered with a damping rubber layer, and the nominal strain is the ratio of the deformation of the damping rubber layer in the sampling area from the start of inflation to the completion of inflation to the initial length; the deformation of the damping rubber layer is the difference between the length of the damping rubber layer when inflation is complete and the initial length; the initial length is the length of the damping rubber layer when the air column bag is not inflated.

[0009] In one alternative embodiment, the air column bag material is a dumbbell-shaped test strip made of an air column bag membrane.

[0010] In an optional implementation, the stress-strain curve of the air column bag material during the tensile process and the deformation corresponding to the nominal strain in the standard data are obtained, and the deformation is saved as the material deformation of the sampling area, including: Obtain stress-strain data of the air column bag material during the tensile process; The first nominal strain, second nominal strain, third nominal strain, fourth nominal strain, fifth nominal strain, and sixth nominal strain are extracted from the standard data. The first nominal strain is the nominal strain generated by the transverse sampling area at the upper end of one side edge of the air column bag during the inflation process. The second nominal strain is the nominal strain generated by the longitudinal sampling area at the lower end of one side edge of the air column bag during the inflation process. The third nominal strain is the nominal strain generated by the transverse sampling area at the center of the air column bag during the inflation process. The fourth nominal strain is the nominal strain generated by the longitudinal sampling area at the center of the air column bag during the inflation process. The fifth nominal strain is the nominal strain generated by the transverse sampling area at the lower end of the other side edge of the air column bag during the inflation process. The sixth nominal strain is the nominal strain generated by the longitudinal sampling area at the upper end of the other side edge of the air column bag during the inflation process. Record the first deformation corresponding to the strain of the air column bag material when it reaches the first nominal strain, the second deformation corresponding to the strain of the air column bag material when it reaches the second nominal strain, the third deformation corresponding to the strain of the air column bag material when it reaches the third nominal strain, the fourth deformation corresponding to the strain of the air column bag material when it reaches the fourth nominal strain, the fifth deformation corresponding to the strain of the air column bag material when it reaches the fifth nominal strain, and the sixth deformation corresponding to the strain of the air column bag material when it reaches the sixth nominal strain. Select a constitutive model, and use the constitutive model to fit the stress-strain curve plotted based on the stress-strain data to obtain the parameters of the constitutive model.

[0011] In an optional implementation, a finite element mesh model of the air column bag is constructed using the stress-strain curve and the material deformation of the sampling region, and simulation analysis is performed based on the finite element mesh model of the air column bag, including: A three-dimensional model of the air column bag in the inflated state is constructed, and the three-dimensional model is imported into finite element model processing software to obtain a finite element mesh model. Import the constitutive model and its parameters into the finite element model processing software; A coordinate system is constructed for the finite element mesh model, and the coordinates of the center point of each sampling region are obtained as the sampling coordinates; Get the first coordinate corresponding to the first shape variable, the second coordinate corresponding to the second shape variable, the third coordinate corresponding to the third shape variable, the fourth coordinate corresponding to the fourth shape variable, the fifth coordinate corresponding to the fifth shape variable, and the sixth coordinate corresponding to the sixth shape variable; Construct a horizontal deformation function that varies with coordinates based on the first deformation variable, the first coordinate, the third deformation variable, the third coordinate, the fifth deformation variable, and the fifth coordinate; Construct a vertical deformation function that varies with coordinates based on the second deformation variable, the second coordinate, the fourth deformation variable, the fourth coordinate, the sixth deformation variable, and the sixth coordinate; The initial deformations of other regions of the finite element mesh model are assigned values ​​based on the horizontal deformation function and the vertical deformation function to obtain the modified model; The modified model is labeled with a closed cavity containing gas, and the gas density, bulk modulus, and ambient pressure are set. Add prestress to the modified model, wherein the prestress is data generated by simulating inflation through an auxiliary model; Define contact data and boundary conditions, and set up a rigid wall to simulate the ground; By setting absolute zero and an ideal gas constant, a simulation is performed to obtain mechanical data.

[0012] Secondly, the present invention provides a simulation analysis system for a buffer air column bag, comprising: The first data acquisition module is used to acquire the nominal strain generated in the sampling area of ​​the air column bag during the inflation process, and save the nominal strain and the sampling area as standard data. The second data acquisition module is used to acquire the stress-strain curve of the air column bag material during the tensile process, and the deformation corresponding to the nominal strain in the standard data, and save the deformation as the material deformation of the sampling area. The modeling and simulation module is used to construct a finite element mesh model of the air column bag from the stress-strain curve and the material deformation of the sampling area, and to perform simulation analysis based on the finite element mesh model of the air column bag.

[0013] In one optional implementation, the first data acquisition module includes: The data query unit is used to obtain the material thickness of the air column bag and retrieve matching standard data from the database based on the material thickness.

[0014] In one optional implementation, the sampling area includes an edge longitudinal sampling area, an edge transverse sampling area, a center longitudinal sampling area, and a center transverse sampling area.

[0015] In an optional embodiment, the sampling area is covered with a damping rubber layer, and the nominal strain is the ratio of the deformation of the damping rubber layer in the sampling area from the start of inflation to the completion of inflation to the initial length; the deformation of the damping rubber layer is the difference between the length of the damping rubber layer when inflation is complete and the initial length; the initial length is the length of the damping rubber layer when the air column bag is not inflated.

[0016] In one alternative embodiment, the air column bag material is a dumbbell-shaped test strip made of an air column bag membrane.

[0017] In one optional implementation, the second data acquisition module includes: The tensile data acquisition unit is used to acquire stress and strain data of the air column bag material during the tensile process; The strain data extraction unit is used to extract a first nominal strain, a second nominal strain, a third nominal strain, a fourth nominal strain, a fifth nominal strain, and a sixth nominal strain from the standard data. The first nominal strain is the nominal strain generated by the transverse sampling area at the upper end of one side edge of the air column bag during the inflation process. The second nominal strain is the nominal strain generated by the longitudinal sampling area at the lower end of one side edge of the air column bag during the inflation process. The third nominal strain is the nominal strain generated by the transverse sampling area at the center of the air column bag during the inflation process. The fourth nominal strain is the nominal strain generated by the longitudinal sampling area at the center of the air column bag during the inflation process. The fifth nominal strain is the nominal strain generated by the transverse sampling area at the lower end of the other side edge of the air column bag during the inflation process. The sixth nominal strain is the nominal strain generated by the longitudinal sampling area at the upper end of the other side edge of the air column bag during the inflation process. The deformation recording unit is used to record the first deformation value corresponding to the first nominal strain of the air column bag material, the second deformation value corresponding to the second nominal strain of the air column bag material, the third deformation value corresponding to the third nominal strain of the air column bag material, the fourth deformation value corresponding to the fourth nominal strain of the air column bag material, the fifth deformation value corresponding to the fifth nominal strain of the air column bag material, and the sixth deformation value corresponding to the sixth nominal strain of the air column bag material. The curve fitting unit is used to select a constitutive model and fit the stress-strain curve plotted based on the stress-strain data using the constitutive model to obtain the parameters of the constitutive model.

[0018] In one optional implementation, the modeling and simulation module includes: The model building unit is used to build a three-dimensional model of the air column bag in the inflated state, and import the three-dimensional model into the finite element model processing software to obtain a finite element mesh model. The parameter import unit is used to import the constitutive model and its parameters into the finite element model processing software. The coordinate construction unit is used to construct a coordinate system for the finite element mesh model and obtain the center point coordinates of each sampling region as the sampling coordinates; The coordinate acquisition unit is used to acquire the first coordinate corresponding to the first shape variable, the second coordinate corresponding to the second shape variable, the third coordinate corresponding to the third shape variable, the fourth coordinate corresponding to the fourth shape variable, the fifth coordinate corresponding to the fifth shape variable, and the sixth coordinate corresponding to the sixth shape variable. The first function generation unit is used to construct a horizontal shape variable function that varies with the coordinates based on the first shape variable, the first coordinate, the third shape variable, the third coordinate, the fifth shape variable, and the fifth coordinate. The second function generation unit is used to construct a vertical deformation function that varies with the coordinates based on the second deformation variable, the second coordinate, the fourth deformation variable, the fourth coordinate, the sixth deformation variable, and the sixth coordinate; The model correction unit is used to assign initial deformation values ​​to other regions of the finite element mesh model based on the horizontal deformation function and the vertical deformation function to obtain the corrected model; A gas configuration unit is used to fill the closed cavity marked in the modified model with gas, and to set the gas density, bulk modulus, and ambient pressure. A stress-adding unit is used to add prestress to the modified model, wherein the prestress is data generated by simulating inflation through an auxiliary model. The environment definition unit is used to define contact data and boundary conditions, and to set up rigid walls to simulate the ground. The simulation execution unit is used to set absolute zero and the ideal gas constant, execute the simulation, and obtain mechanical data.

[0019] Thirdly, a terminal is provided, including: Processor, memory, among which, This memory is used to store computer programs. The processor is used to retrieve and run the computer program from memory, causing the terminal to perform the terminal method described above.

[0020] Fourthly, a computer storage medium is provided, wherein instructions are stored therein, which, when executed on a computer, cause the computer to perform the methods described in the above aspects.

[0021] The beneficial effects of this invention are that the cushioning air column bag simulation analysis method, system, terminal and storage medium provided by this invention construct a finite element mesh model by acquiring the strain generated by the air column bag during the inflation process and acquiring the stress-strain curve of the material. The gas region, gas parameters, prestress and environmental parameters are configured for the finite element mesh model. On this basis, collision simulation is performed to obtain the mechanical data of the air column bag in the collision scenario. The finite element mesh model constructed in this way is closer to the real air column bag and can obtain more accurate mechanical data.

[0022] The present invention provides a simulation analysis method, system, terminal and storage medium for air column bags. It uses damping adhesive to test the deformation of a local area of ​​the air column bag during inflation, thereby obtaining the standard nominal strain of the sampling area of ​​the air column bag. It further conducts a tensile test on the air column bag material to collect the deformation of the air column bag material under the standard nominal strain. Finally, it corrects the model based on the inflation deformation of each sampling area to further improve the simulation accuracy.

[0023] The present invention provides a method, system, terminal and storage medium for simulating and analyzing buffer air column bags. After modeling, the present invention sets the position of the air column in the model and configures the gas parameters. In this way, the model includes both the membrane part and the gas part, and its overall mechanical properties are consistent with those of the real air column bag. The mechanical data obtained from the simulation are close to the real data.

[0024] Furthermore, the design principle of this invention is reliable, the structure is simple, and it has a very wide range of application prospects. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic flowchart of a method according to an embodiment of the present invention.

[0027] Figure 2 This is another illustrative flowchart of a method according to an embodiment of the present invention.

[0028] Figure 3 This is a schematic diagram of the sampling area location in a method according to an embodiment of the present invention.

[0029] Figure 4 This is a schematic block diagram of a system according to an embodiment of the present invention.

[0030] Figure 5 This is a schematic diagram of the structure of a terminal provided in an embodiment of the present invention. Detailed Implementation

[0031] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0033] The key terms used in this invention will be explained below.

[0034] Polyethylene foam, also known as EPE pearl cotton, is a non-crosslinked closed-cell structure and is a new type of environmentally friendly packaging material.

[0035] Hypermesh software is a CAE application package that integrates various tools needed for design and analysis.

[0036] The cushioning air column bag simulation analysis method provided in this embodiment of the invention is executed by a computer device, and correspondingly, the cushioning air column bag simulation analysis system runs in the computer device.

[0037] Figure 1 This is a schematic flowchart illustrating a method according to an embodiment of the present invention. Wherein, Figure 1 The executing entity can be a buffer air column bag simulation analysis system. Depending on different requirements, the order of steps in this flowchart can be changed, and some can be omitted.

[0038] like Figure 1 As shown, the method includes: Step 110: Obtain the nominal strain generated in the sampling area of ​​the air column bag during the inflation process, and save the nominal strain and the sampling area as standard data; Step 120: Obtain the stress-strain curve of the air column bag material during the tensile process, and the deformation corresponding to the nominal strain in the standard data, and save the deformation as the material deformation of the sampling area; Step 130: Construct a finite element mesh model of the air column bag using the stress-strain curve and the material deformation of the sampling area, and perform simulation analysis based on the finite element mesh model of the air column bag.

[0039] To facilitate understanding of the present invention, the following description further illustrates the simulation analysis method for buffer air column bags provided by the present invention, based on the principle of the present invention and in conjunction with the simulation analysis process of buffer air column bags in the embodiments.

[0040] For details, please refer to Figure 2 The simulation analysis method for the buffer air column bag includes: S1. Obtain the nominal strain generated in the sampling area of ​​the air column bag during the inflation process, and save the nominal strain and the sampling area as standard data.

[0041] The nominal strain generated in the sampling area of ​​the air column bag during the inflation process is obtained in advance through mechanical tests, and these data are saved to the database.

[0042] The mechanical test process is as follows: Three thicknesses are commonly used and are named T1, T2, and T3 respectively. Coating of each thickness from Figure 3 As shown, three samples are taken from regions 1, 2, and 3, both horizontally and vertically. For example, for a membrane with a thickness of T1, the first horizontal sample from region 1 is named T1-1-H1, and the first vertical sample is named T1-1-V1.

[0043] Since the performance of the test strips needs to be tested under tension, a specific tension state needs to be obtained. A thin layer of damping adhesive (stretchable, non-rebounding) is applied along both the longitudinal and transverse directions in the uninflated state, as shown below. Figure 5 shown AB=l 1 and CD=l 2. After inflation, tear off the damping rubber and measure the length after stretching. l 3 and l 4. The nominal strains in the longitudinal and transverse directions are respectively ε 1 =(l 3 -l 1 ) / l 1 , ε 2 =(l 4 -l 2 ) / l 2.

[0044] When simulation is required, the material thickness of the target air column bag is obtained, and matching standard data is retrieved from the database based on the material thickness.

[0045] S2. Obtain the stress-strain curve of the air column bag material during the tensile process, and the deformation corresponding to the nominal strain in the standard data, and save the deformation as the material deformation of the sampling area.

[0046] Obtain the stress-strain data of the air column bag material during the tensile process; extract the first nominal strain, second nominal strain, third nominal strain, fourth nominal strain, fifth nominal strain, and sixth nominal strain from the standard data, wherein the first nominal strain is the nominal strain generated by the transverse sampling area at the upper edge of one side of the air column bag during the inflation process, the second nominal strain is the nominal strain generated by the longitudinal sampling area at the lower edge of one side of the air column bag during the inflation process, the third nominal strain is the nominal strain generated by the transverse sampling area at the center of the air column bag during the inflation process, the fourth nominal strain is the nominal strain generated by the longitudinal sampling area at the center of the air column bag during the inflation process, the fifth nominal strain is the nominal strain generated by the transverse sampling area at the lower edge of the other side of the air column bag during the inflation process, and the sixth nominal strain... The nominal strain is the nominal strain generated in the longitudinal sampling area at the upper edge of the other side of the air column bag during the inflation process; the first deformation corresponding to the strain of the air column bag material reaching the first nominal strain, the second deformation corresponding to the strain of the air column bag material reaching the second nominal strain, the third deformation corresponding to the strain of the air column bag material reaching the third nominal strain, the fourth deformation corresponding to the strain of the air column bag material reaching the fourth nominal strain, the fifth deformation corresponding to the strain of the air column bag material reaching the fifth nominal strain, and the sixth deformation corresponding to the strain of the air column bag material reaching the sixth nominal strain; a constitutive model is selected, and the stress-strain curve drawn based on the stress-strain data is fitted using the constitutive model to obtain the parameters of the constitutive model.

[0047] Specifically, the test strip is clamped using fixtures, and the distance between the upper and lower ends of the equipment is adjusted to bring the test strip into a taut state. Let the initial distance between the upper and lower clamps be... l The adjusted distance is l+Δl At this time, the nominal strain of the sample is ε=Δl / l When stretching the longitudinal sampling strip, make ε=ε 1. When stretching the transverse test strip, make ε=ε 2 ， Find them separately Δl .

[0048] During the stretching process, the stress-strain curve is recorded and the data is saved as a text or Excel file for further processing. Based on the stretching curve, an appropriate constitutive model is selected, such as linear elastic, nonlinear elastic, elastoplastic, hyperelastic, viscoelastic, etc., and the parameters of the selected constitutive model are obtained by fitting the stress-strain curve.

[0049] S3. Construct a finite element mesh model of the air column bag using the stress-strain curve and the material deformation of the sampling area, and perform simulation analysis based on the finite element mesh model of the air column bag.

[0050] A three-dimensional model of the air column bag in an inflated state is constructed, and the three-dimensional model is imported into finite element model processing software to obtain a finite element mesh model. The constitutive model and its parameters are imported into the finite element model processing software. A coordinate system is constructed for the finite element mesh model, and the center point coordinates of each sampling area are obtained as sampling coordinates. The first coordinate corresponding to the first deformation variable, the second coordinate corresponding to the second deformation variable, the third coordinate corresponding to the third deformation variable, the fourth coordinate corresponding to the fourth deformation variable, the fifth coordinate corresponding to the fifth deformation variable, and the sixth coordinate corresponding to the sixth deformation variable are obtained. Based on the first deformation variable, the first coordinate, the third deformation variable, the third coordinate, the fifth deformation variable, and the fifth coordinate, a lateral deformation variable is constructed that varies with the coordinates. The model is divided into two parts: a transverse deformation function and a longitudinal deformation function. The transverse and longitudinal deformation functions are used to construct the initial deformations of other regions of the finite element mesh model, resulting in a modified model. The modified model is labeled with a gas within a closed cavity, and the gas density, bulk modulus, and ambient pressure are set. Prestress is added to the modified model, and this prestress is generated by simulating inflation using an auxiliary model. Contact data and boundary conditions are defined, and a rigid wall is set to simulate the ground. Absolute zero and an ideal gas constant are set, and simulation is performed to obtain mechanical data.

[0051] Specifically, the following processes are protected: Finite element processing section: The front-end obtains a detailed 3D model of the air column bag cushioning design scheme for a certain product. The 3D model is then imported into the finite element preprocessing software Hypermesh. Geometry cleanup and mesh generation are performed. Shell elements are used for meshing the coating material, with the element type selected as S4R. Two rows of elements are needed at the connections between unit cells, and triangular elements should be avoided as much as possible. The gas encased inside the coating does not require meshing. For the adhesive at the corners, where two layers of coating are bonded, common nodes or cohensive elements can be used for connection. Material and properties are defined by setting different thickness properties for different parts of the coating using shell element properties. The coating material is set using the parameters obtained in the last step of the first part. The server's overall model is imported into Hypermesh and then assembled with the air column bag finite element model. After assembly, the mesh is checked for penetration and interference.

[0052] In the constructed finite element mesh model, initial deformation caused by inflation is added. Specifically, when constructing the horizontal deformation function and the vertical deformation function, a two-variable linear equation is used. The parameter values ​​are obtained by substituting the coordinates and deformation of the sampling area.

[0053] Simulation settings section: Import the finite element mesh model exported from Hypermesh into Abaqus, name the model Whole-model, and configure the simulation settings. For the analysis step, select Dynamic Explicit, and set the total computation time to 0.05 seconds. Define the fluid cavity. First, define the fluid cavity property. In the Abaqus software, click "Create Interaction Property" in the interaction interface. In the pop-up dialog box, select Fluid Cavity and click the "Continue" button. In the "Edit Interaction Property" dialog box, select "Pneumatic" for definition, indicating that the closed cavity contains gas. Then, set the gas density in Fluid Density, check "Specify Fluid Bulk Modulus," and enter the gas bulk modulus in Fluid Bulk Modulus. Next, click the "Create Interaction" icon, select Fluid Cavity in the pop-up dialog box, and click the "Continue" button. In the graphics window, select "Cavity Point." The cavity point needs to be defined beforehand inside the closed cavity; one point needs to be defined for each unit cell. After selecting the Cavity Point, click the middle mouse button. A prompt will appear in the graphics window to select the Cavity Surface. Select the surface of the enclosed air chamber and click the middle mouse button again. The Edit Interaction dialog box will pop up. In Fluid Cavity Property, select the intProp-1 property defined above, check Specify Ambient Pressure, enter the ambient pressure, and click the OK button to complete the definition of the fluid cavity.

[0054] Adding prestress to the coating material is the most crucial step in the entire simulation. Obtaining the prestress of the air chamber after inflation from a planar position is challenging because the 3D model obtained from the simulation already shows the inflated state. Simulating the entire inflation process and then folding and bonding the inflated airbag would require significant computation time, and bonding during the simulation is difficult to implement. Considering that the airbag remains in an elastic state during inflation, the elastic equilibrium equation based on the small deformation assumption indicates that stress is only related to external forces. Therefore, the prestress state of the inflated airbag can be determined through equivalent substitution. In Abaqus, a whole-model is copied to generate a new computational model named Air-bag-alone. Other meshes are deleted, leaving only the finite element model of the airbag. A very large Young's modulus is assigned to the coating material of the airbag. An inflation pressure p0 is applied to the inner wall, and the calculation is performed. The results are saved and named pre-stress.odb. Return to the Whole-model settings, select "initial" for "step" in "predefined field", select "stress" for "types for selected step", then select the finite element mesh of the air column bag. In the pop-up dialog box, select "from output database file" for "specification" and "pre-stress.odb" for "file name" to apply the prestress to the air column bag.

[0055] To define contact, first create contact properties. Here, you need to define the normal and tangential forces of the contact. The tangential force includes the relative motion between the contact surfaces and any possible frictional shear stress. The normal force defines the relationship between the contact force and the contact gap. The normal force uses a hard contact algorithm, and the tangential force uses a friction model, defining the tangential friction coefficient as 0.2.

[0056] Define boundary conditions. In the load module, click the "Create Predefined Field" icon. The step defaults to "Initial." Select "Mechanical" for the category and "Velocity" for the types for selected steps. Apply an initial velocity in the drop direction to all nodes of the product, with the velocity value v = (2gh)¹ / ², where h is the drop height specified in the experimental standard. Follow the same steps to the category, select "Other," and choose "Fluid Cavity Pressure" for the types for selected steps to define the initial pressure in the air column bag's air chamber. Click the "Create Load" icon to define the gravity field, setting the acceleration to 9.81 m / s², with the direction pointing towards the drop direction.

[0057] Set up a rigid wall to simulate the ground. The rigid wall can be an analytical rigid body or a discrete rigid body. Its area should be much larger than the outer dimensions of the packaged product. Constrain all degrees of freedom of the rigid wall.

[0058] Double-click Whole-model, set the absolute zero and ideal gas constant in the pop-up dialog box, and then close the dialog box. Return to the job module and submit the calculation.

[0059] In some embodiments, the air column bag simulation analysis system may include multiple functional modules composed of computer program segments. The computer programs for each program segment in the air column bag simulation analysis system may be stored in the memory of a computer device and executed by at least one processor to perform (see details). Figure 1 (Description) Functionality of buffer air column bag simulation analysis.

[0060] In this embodiment, the buffer air column bag simulation analysis system can be divided into multiple functional modules according to its functions, such as... Figure 4 As shown. The functional modules of system 400 may include: a first data acquisition module 410, a second data acquisition module 420, and a modeling and simulation module 430. The module referred to in this invention is a series of computer program segments that can be executed by at least one processor and perform a fixed function, and are stored in memory. In this embodiment, the functions of each module will be described in detail in subsequent embodiments.

[0061] The first data acquisition module is used to acquire the nominal strain generated in the sampling area of ​​the air column bag during the inflation process, and save the nominal strain and the sampling area as standard data. The second data acquisition module is used to acquire the stress-strain curve of the air column bag material during the tensile process, and the deformation corresponding to the nominal strain in the standard data, and save the deformation as the material deformation of the sampling area. The modeling and simulation module is used to construct a finite element mesh model of the air column bag from the stress-strain curve and the material deformation of the sampling area, and to perform simulation analysis based on the finite element mesh model of the air column bag.

[0062] Optionally, as an embodiment of the present invention, the first data acquisition module includes: The data query unit is used to obtain the material thickness of the air column bag and retrieve matching standard data from the database based on the material thickness.

[0063] Optionally, as an embodiment of the present invention, the sampling area includes an edge longitudinal sampling area, an edge transverse sampling area, a center longitudinal sampling area, and a center transverse sampling area.

[0064] Optionally, as an embodiment of the present invention, the sampling area is covered with a damping rubber layer, and the nominal strain is the ratio of the deformation of the damping rubber layer in the sampling area from the start of inflation to the completion of inflation to the initial length; the deformation of the damping rubber layer is the difference between the length of the damping rubber layer when inflation is completed and the initial length; the initial length is the length of the damping rubber layer in the uninflated state of the air column bag.

[0065] Optionally, as an embodiment of the present invention, the air column bag material is a dumbbell-shaped test strip made of an air column bag film.

[0066] Optionally, as an embodiment of the present invention, the second data acquisition module includes: The tensile data acquisition unit is used to acquire stress and strain data of the air column bag material during the tensile process; The strain data extraction unit is used to extract a first nominal strain, a second nominal strain, a third nominal strain, a fourth nominal strain, a fifth nominal strain, and a sixth nominal strain from the standard data. The first nominal strain is the nominal strain generated by the transverse sampling area at the upper end of one side edge of the air column bag during the inflation process. The second nominal strain is the nominal strain generated by the longitudinal sampling area at the lower end of one side edge of the air column bag during the inflation process. The third nominal strain is the nominal strain generated by the transverse sampling area at the center of the air column bag during the inflation process. The fourth nominal strain is the nominal strain generated by the longitudinal sampling area at the center of the air column bag during the inflation process. The fifth nominal strain is the nominal strain generated by the transverse sampling area at the lower end of the other side edge of the air column bag during the inflation process. The sixth nominal strain is the nominal strain generated by the longitudinal sampling area at the upper end of the other side edge of the air column bag during the inflation process. The deformation recording unit is used to record the first deformation value corresponding to the first nominal strain of the air column bag material, the second deformation value corresponding to the second nominal strain of the air column bag material, the third deformation value corresponding to the third nominal strain of the air column bag material, the fourth deformation value corresponding to the fourth nominal strain of the air column bag material, the fifth deformation value corresponding to the fifth nominal strain of the air column bag material, and the sixth deformation value corresponding to the sixth nominal strain of the air column bag material. The curve fitting unit is used to select a constitutive model and fit the stress-strain curve plotted based on the stress-strain data using the constitutive model to obtain the parameters of the constitutive model.

[0067] Optionally, as an embodiment of the present invention, the modeling and simulation module includes: The model building unit is used to build a three-dimensional model of the air column bag in the inflated state, and import the three-dimensional model into the finite element model processing software to obtain a finite element mesh model. The parameter import unit is used to import the constitutive model and its parameters into the finite element model processing software. The coordinate construction unit is used to construct a coordinate system for the finite element mesh model and obtain the center point coordinates of each sampling region as the sampling coordinates; The coordinate acquisition unit is used to acquire the first coordinate corresponding to the first shape variable, the second coordinate corresponding to the second shape variable, the third coordinate corresponding to the third shape variable, the fourth coordinate corresponding to the fourth shape variable, the fifth coordinate corresponding to the fifth shape variable, and the sixth coordinate corresponding to the sixth shape variable. The first function generation unit is used to construct a horizontal shape variable function that varies with the coordinates based on the first shape variable, the first coordinate, the third shape variable, the third coordinate, the fifth shape variable, and the fifth coordinate. The second function generation unit is used to construct a vertical deformation function that varies with the coordinates based on the second deformation variable, the second coordinate, the fourth deformation variable, the fourth coordinate, the sixth deformation variable, and the sixth coordinate; The model correction unit is used to assign initial deformation values ​​to other regions of the finite element mesh model based on the horizontal deformation function and the vertical deformation function to obtain the corrected model; A gas configuration unit is used to fill the closed cavity marked in the modified model with gas, and to set the gas density, bulk modulus, and ambient pressure. A stress-adding unit is used to add prestress to the modified model, wherein the prestress is data generated by simulating inflation through an auxiliary model. The environment definition unit is used to define contact data and boundary conditions, and to set up rigid walls to simulate the ground. The simulation execution unit is used to set absolute zero and the ideal gas constant, execute the simulation, and obtain mechanical data.

[0068] Figure 5 This is a schematic diagram of a terminal 500 provided in an embodiment of the present invention. The terminal 500 can be used to execute the buffer air column bag simulation analysis method provided in the embodiment of the present invention.

[0069] The terminal 500 may include a processor 510, a memory 520, and a communication unit 530. These components communicate via one or more buses. Those skilled in the art will understand that the server structure shown in the figure does not constitute a limitation of the present invention. It may be a bus topology or a star topology, and may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0070] The memory 520 can be used to store the execution instructions of the processor 510. The memory 520 can be implemented by any type of volatile or non-volatile memory terminal or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk. When the execution instructions in the memory 520 are executed by the processor 510, the terminal 500 is able to perform some or all of the steps in the above method embodiments.

[0071] The processor 510 serves as the control center of the storage terminal, connecting various parts of the electronic terminal via various interfaces and lines. It executes software programs and / or modules stored in the memory 520, and calls data stored in the memory to perform various functions of the electronic terminal and / or process data. The processor can be composed of integrated circuits (ICs), such as a single packaged IC or multiple packaged ICs with the same or different functions connected together. For example, the processor 510 may consist only of a central processing unit (CPU). In this embodiment of the invention, the CPU may have a single processing core or include multiple processing cores.

[0072] The communication unit 530 is used to establish a communication channel, enabling the storage terminal to communicate with other terminals. It can receive user data sent by other terminals or send user data to other terminals.

[0073] The present invention also provides a computer storage medium, wherein the computer storage medium may store a program, which, when executed, may include some or all of the steps provided in the embodiments of the present invention. The storage medium may be a magnetic disk, an optical disk, read-only memory (ROM), or random access memory (RAM), etc.

[0074] Therefore, this invention constructs a finite element mesh model by acquiring the strain generated by the air column bag during inflation and the stress-strain curve of the material. The finite element mesh model is configured with gas regions, gas parameters, prestress, and environmental parameters. Based on this, a collision simulation is performed to obtain the mechanical data of the air column bag in the collision scenario. The finite element mesh model constructed in this way is closer to the real air column bag and can obtain more accurate mechanical data. The technical effects achieved by this embodiment can be found in the description above, and will not be repeated here.

[0075] Those skilled in the art will clearly understand that the techniques in the embodiments of the present invention can be implemented using software plus necessary general-purpose hardware platforms. Based on this understanding, the technical solutions in the embodiments of the present invention, or the parts that contribute to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium such as a USB flash drive, mobile hard drive, read-only memory (ROM), random access memory (RAM), magnetic disk, or optical disk, or other media capable of storing program code. It includes several instructions to cause a computer terminal (which may be a personal computer, server, or a second terminal, network terminal, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention.

[0076] The same or similar parts between the various embodiments in this specification can be referred to mutually. In particular, the terminal embodiments are basically similar to the method embodiments, so the description is relatively simple, and the relevant parts can be referred to the description in the method embodiments.

[0077] In the embodiments provided by this invention, it should be understood that the disclosed systems and methods can be implemented in other ways. For example, the system embodiments described above are merely illustrative. For instance, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between systems or modules may be electrical, mechanical, or other forms.

[0078] The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical modules; that is, they may be located in one place or distributed across multiple network modules. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0079] In addition, the functional modules in the various embodiments of the present invention can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module.

[0080] Although the present invention has been described in detail with reference to the accompanying drawings and preferred embodiments, the invention is not limited thereto. Various equivalent modifications or substitutions can be made to the embodiments of the invention by those skilled in the art without departing from the spirit and essence of the invention, and such modifications or substitutions should all be within the scope of the invention. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the invention should also be covered within the protection scope of the invention. Therefore, the protection scope of the invention should be determined by the scope of the claims.

Claims

1. A simulation analysis method for a buffer air column bag, characterized in that, include: Obtain the nominal strain generated in the sampling area of ​​the air column bag during the inflation process, and save the nominal strain and the sampling area as standard data; Obtain the stress-strain curve of the air column bag material during the tensile process, and the deformation corresponding to the nominal strain in the standard data, and save the deformation as the material deformation of the sampling area; A finite element mesh model of an air column bag is constructed using the stress-strain curve and the material deformation of the sampling area, and simulation analysis is performed based on the finite element mesh model of the air column bag. The sampling area includes: a transverse sampling area at the upper edge of one side of the air column bag, a longitudinal sampling area at the lower edge of one side of the air column bag, a transverse sampling area at the center of the air column bag, a longitudinal sampling area at the center of the air column bag, a transverse sampling area at the lower edge of the other side of the air column bag, and a longitudinal sampling area at the upper edge of the other side of the air column bag.

2. The method according to claim 1, characterized in that, Obtain the nominal strain generated in the sampling area of ​​the air column bag during the inflation process, and save the nominal strain and the sampling area as standard data, including: The material thickness of the air column bag is obtained, and matching standard data is retrieved from the database based on the material thickness.

3. The method according to claim 2, characterized in that, The sampling area includes an edge longitudinal sampling area, an edge transverse sampling area, a center longitudinal sampling area, and a center transverse sampling area.

4. The method according to claim 2, characterized in that, The sampling area is covered with a damping rubber layer. The nominal strain is the ratio of the deformation of the damping rubber layer in the sampling area from the start of inflation to the completion of inflation to the initial length. The deformation of the damping rubber layer is the difference between the length of the damping rubber layer when inflation is complete and the initial length. The initial length is the length of the damping rubber layer when the air column bag is not inflated.

5. The method according to claim 1, characterized in that, The air column bag material is a dumbbell-shaped test strip made of air column bag film.

6. The method according to claim 1 or 5, characterized in that, Acquire the stress-strain curve of the air column bag material during the tensile process, and the deformation corresponding to the nominal strain in the standard data, and save the deformation as the material deformation of the sampling area, including: Obtain stress-strain data of the air column bag material during the tensile process; The first nominal strain, second nominal strain, third nominal strain, fourth nominal strain, fifth nominal strain, and sixth nominal strain are extracted from the standard data. The first nominal strain is the nominal strain generated by the transverse sampling area at the upper end of one side edge of the air column bag during the inflation process. The second nominal strain is the nominal strain generated by the longitudinal sampling area at the lower end of one side edge of the air column bag during the inflation process. The third nominal strain is the nominal strain generated by the transverse sampling area at the center of the air column bag during the inflation process. The fourth nominal strain is the nominal strain generated by the longitudinal sampling area at the center of the air column bag during the inflation process. The fifth nominal strain is the nominal strain generated by the transverse sampling area at the lower end of the other side edge of the air column bag during the inflation process. The sixth nominal strain is the nominal strain generated by the longitudinal sampling area at the upper end of the other side edge of the air column bag during the inflation process. Record the first deformation corresponding to the strain of the air column bag material when it reaches the first nominal strain, the second deformation corresponding to the strain of the air column bag material when it reaches the second nominal strain, the third deformation corresponding to the strain of the air column bag material when it reaches the third nominal strain, the fourth deformation corresponding to the strain of the air column bag material when it reaches the fourth nominal strain, the fifth deformation corresponding to the strain of the air column bag material when it reaches the fifth nominal strain, and the sixth deformation corresponding to the strain of the air column bag material when it reaches the sixth nominal strain. Select a constitutive model, and use the constitutive model to fit the stress-strain curve plotted based on the stress-strain data to obtain the parameters of the constitutive model.

7. The method according to claim 6, characterized in that, A finite element mesh model of the air column bag is constructed using the stress-strain curve and the material deformation of the sampling area. Simulation analysis is then performed based on this finite element mesh model, including: A three-dimensional model of the air column bag in the inflated state is constructed, and the three-dimensional model is imported into finite element model processing software to obtain a finite element mesh model. Import the constitutive model and its parameters into the finite element model processing software; A coordinate system is constructed for the finite element mesh model, and the coordinates of the center point of each sampling region are obtained as the sampling coordinates; Get the first coordinate corresponding to the first shape variable, the second coordinate corresponding to the second shape variable, the third coordinate corresponding to the third shape variable, the fourth coordinate corresponding to the fourth shape variable, the fifth coordinate corresponding to the fifth shape variable, and the sixth coordinate corresponding to the sixth shape variable; Construct a horizontal deformation function that varies with coordinates based on the first deformation variable, the first coordinate, the third deformation variable, the third coordinate, the fifth deformation variable, and the fifth coordinate; Construct a vertical deformation function that varies with coordinates based on the second deformation variable, the second coordinate, the fourth deformation variable, the fourth coordinate, the sixth deformation variable, and the sixth coordinate; The initial deformations of other regions of the finite element mesh model are assigned values ​​based on the horizontal deformation function and the vertical deformation function to obtain the modified model; The modified model is labeled with a closed cavity containing gas, and the gas density, bulk modulus, and ambient pressure are set. Add prestress to the modified model, wherein the prestress is data generated by simulating inflation through an auxiliary model; Define contact data and boundary conditions, and set up a rigid wall to simulate the ground; Set absolute zero and ideal gas constant, execute simulation, and obtain mechanical data.

8. A simulation analysis system for a buffer air column bag, characterized in that, include: The first data acquisition module is used to acquire the nominal strain generated in the sampling area of ​​the air column bag during the inflation process, and save the nominal strain and the sampling area as standard data. The second data acquisition module is used to acquire the stress-strain curve of the air column bag material during the tensile process, and the deformation corresponding to the nominal strain in the standard data, and save the deformation as the material deformation of the sampling area. The modeling and simulation module is used to construct a finite element mesh model of the air column bag from the stress-strain curve and the material deformation of the sampling area, and to perform simulation analysis based on the finite element mesh model of the air column bag. The sampling area includes: a transverse sampling area at the upper edge of one side of the air column bag, a longitudinal sampling area at the lower edge of one side of the air column bag, a transverse sampling area at the center of the air column bag, a longitudinal sampling area at the center of the air column bag, a transverse sampling area at the lower edge of the other side of the air column bag, and a longitudinal sampling area at the upper edge of the other side of the air column bag.

9. A terminal, characterized in that, include: The memory is used to store the simulation analysis program for the buffer air column bag. A processor is configured to implement the steps of the buffer air column bag simulation analysis method as described in any one of claims 1-7 when executing the buffer air column bag simulation analysis program.

10. A computer-readable storage medium storing a computer program, characterized in that, The readable storage medium stores a buffer air column bag simulation analysis program, which, when executed by a processor, implements the steps of the buffer air column bag simulation analysis method as described in any one of claims 1-7.

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