Finite element full-model calculation method for transient high-pressure gas driven steel ball

Abstract

The invention relates to a transient high-pressure gas driven steel ball finite element full-model calculation method, which comprises the following steps of: establishing a three-dimensional geometric model containing air, high-pressure gas, a steel ball and a shell, and defining material attributes of each part, including a high-pressure gas state equation, a steel ball elastic modulus, a shell yield strength and the like; according to the method, finite element grids are divided by adopting a specific method, the steel balls are converted into dem particles, shell hexahedral grids are formed, SALE structured grids with default structures are adopted for high-pressure gas and air, and accurate simulation of the movement process of the steel balls driven by the high-pressure gas is achieved by utilizing lsdyna solving and lsprepost post-processing; according to the method, the speed of generating the steel ball model is increased by more than 50%, efficient construction of a large-scale model is supported, the calculation efficiency is improved, the accuracy is high, the complex arrangement structure of the steel balls can be reflected, the expandability is high, the method is suitable for high-pressure gas cavities and steel balls of different shapes, sizes and materials, and the method can be expanded to other transient gas driving systems. And a reliable basis is provided for system design and optimization.

Description

Technical Field

[0001] The present invention relates to the field of fluid mechanics technology, and in particular to a finite element full model calculation method for a transient high-pressure gas-driven steel ball. Background Art

[0002] As an important experimental and testing method, the transient high-pressure gas-driven steel ball system plays a key role in many fields, including impact testing, material performance testing, and product design optimization. For example, in the aerospace field, the transient high-pressure gas-driven steel ball system can be used to simulate the stress conditions of aircraft components under the impact of high-speed airflow; in the automotive industry, it can be used to test the safety and reliability of automotive parts during collisions; in the field of materials science, it can help researchers explore the response characteristics of materials under extreme mechanical conditions. Therefore, accurately simulating the motion process of steel balls driven by high-pressure gas is extremely important for optimizing system optimization, improving drive efficiency, and ensuring safe and stable system operation. Traditional analysis methods often employ simplified models or the ALEX (arbitrary lagrangian-eulerian) method. However, these traditional methods have numerous limitations when dealing with complex physical phenomena. Simplified models often overlook key details in the system, such as the complex arrangement of steel balls and the subtle interactions between high-pressure gas, the balls, and the shell, leading to significant deviations between the simulation results and the actual results. While the ALEX method can address fluid-solid interactions to a certain extent, it suffers from low computational efficiency when dealing with large-scale, complex models and scenarios requiring high precision. It struggles to quickly and accurately reflect the transient dynamic characteristics of the system, and thus fails to meet the urgent need for efficient and accurate simulation in modern engineering design. Furthermore, with the continuous expansion of application scenarios and increasing technical requirements, traditional methods have gradually exposed problems such as limited applicability and insufficient scalability when dealing with high-pressure gas chambers and steel ball combinations of various shapes, sizes, and materials, making them difficult to adapt to the diverse and complex application requirements of actual engineering. Summary of the Invention

[0003] In view of this, the present invention provides a finite element full model calculation method for a transient high-pressure gas-driven steel ball, which can solve the problem that the existing technology is difficult to quickly and accurately respond to the complex physical phenomena of the system, and can accurately simulate the movement process of the steel ball driven by high-pressure gas, providing a reliable basis for system design and optimization.

[0004] To achieve the above object, the present invention provides a method for calculating a finite element full model of a transient high-pressure gas-driven steel ball, comprising the following steps: S1. Establish a three-dimensional geometric model of the steel ball, including air, high-pressure gas, steel ball and shell; S2. defining the material properties of each component in the three-dimensional geometric model of the steel ball, including the state equation of the high-pressure gas, the elastic modulus and Poisson's ratio of the steel ball, and the tensile strength, yield strength, and Poisson's ratio of the shell; S3, perform finite element mesh division; S301, performing finite element surface meshing on the three-dimensional geometric model of the steel ball; S302, converting the surface mesh into dem particles, and simulating the motion behavior of the steel ball using discrete element method, where each dem particle represents a steel ball; S303, using hexahedral meshing for the shell; S304, adopt the default SALE structured grid for high pressure gas and air; S4. Use *ALE_COUPLING_NODAL_CONSTRAINT_ID to simulate the contact interaction between the steel ball and the high-pressure gas, and calculate the required information through lsdyna; S401, applying node constraints at the contact interface between the steel ball and the high-pressure gas to complete momentum and energy transfer; S402. Use *ALE_STRUCTURED_FSI leak-free coupling to simulate the flow of high-pressure gas inside the shell and the deformation response of the shell under the action of high-pressure gas. S403. Set the solution parameters and use the LSDyna solver to calculate the motion and dispersion process of the steel ball driven by high-pressure gas. The position, velocity, acceleration, and stress-strain data of the steel ball at each moment are obtained through LSPrepost processing. The motion law, distribution density, and dispersion velocity of the steel ball are obtained through analysis.

[0005] Preferably, the high-pressure gas cavity of the steel ball three-dimensional geometric model adopts *INITIAL_VOLUME_FRACTION_GEOMETRY to fill the complex structural model.

[0006] Preferably, the state equation of the high-pressure gas in the three-dimensional geometric model of the steel ball adopts the ideal gas state equation, which is expressed as: ; in, represents the gas pressure, represents the volume of gas, represents the amount of gaseous substance, represents the ideal gas constant, Indicates the gas temperature; The steel ball adopts the rigid material constitutive model, and the elastic modulus , Poisson's ratio ; The shell is made of *MAT_PLASTIC_KINEMATIC material, with tensile strength , yield strength , elastic modulus , Poisson's ratio .

[0007] Compared with the prior art, the present invention has the following beneficial effects: The present invention uses a full-model calculation method to adaptively capture the flow characteristics of high-pressure gas and its interaction with the surrounding air. Without the need for complex finite element meshing, the speed of generating steel ball models is increased by more than 50%, thereby improving the model generation speed, supporting the efficient construction of large-scale models, and greatly improving the calculation efficiency while ensuring calculation accuracy. At the same time, it can accurately reflect the complex arrangement structure of steel balls, and the simulation results are highly accurate. It is suitable for high-pressure gas cavities and steel balls of various shapes, sizes and materials, and has a wide applicability. In addition, the method provided by the present invention has the advantage of strong scalability and can be easily extended to other types of transient gas drive systems, providing strong technical support for engineering design and scientific research in related fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG1 is a scattering cloud diagram of a steel ball model driven by transient high-pressure gas according to the present invention; Figure 2 Schematic diagram of the finite element model of the present invention; Figure 3 This is the mesh division diagram of the steel sphere surface of the present invention; Figure 4 Schematic diagram of steel ball particle dispersion of the present invention. DETAILED DESCRIPTION

[0009] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the specific implementation methods, structures, features and effects of the present invention are described in detail below in conjunction with the accompanying drawings and preferred embodiments.

[0010] The implementation process of the present invention is described in detail against the backdrop of a transient high-pressure gas-driven steel ball system in a material impact test. This embodiment simulates the impact process of a target material driven by high-pressure gas and studies the mechanical response characteristics of the target material under high-speed impact loads.

[0011] like Figure 1 As shown, the transient high-pressure gas driven steel ball model includes high-pressure gas 1, steel ball 2 and shell 3; the high-pressure gas 1 is filled in the air, the steel ball 2 is located outside the high-pressure gas 1, and the shell 3 is located inside the steel ball 2; This embodiment provides a method for calculating a finite element full model of a transient high-pressure gas-driven steel ball, comprising the following steps: S1. Use CATIA software to create a three-dimensional geometric model including air, high-pressure gas, steel ball, and shell. The shape and size of the high-pressure gas chamber in the model are designed according to the actual test device, the diameter and material of the steel ball are set according to the test requirements, and the size and material of the shell are determined according to the actual load-bearing capacity and structural design requirements. S2. defining the material properties of each component in the three-dimensional geometric model of the steel ball, including the state equation of the high-pressure gas, the elastic modulus and Poisson's ratio of the steel ball, and the tensile strength, yield strength, and Poisson's ratio of the shell; The state equation of the high-pressure gas in the three-dimensional geometric model of the steel ball adopts the ideal gas state equation, which is expressed as: ; in, represents the gas pressure, represents the volume of gas, represents the amount of gaseous substance, represents the ideal gas constant, Indicates the gas temperature. In this embodiment, the initial pressure of the high-pressure gas is , temperature is 300K; The steel ball adopts the *MAT_RIGID material constitutive model, and the elastic modulus is , Poisson's ratio , the density is ; The shell is made of *MAT_PLASTIC_KINEMATIC material with tensile strength , yield strength , elastic modulus , Poisson's ratio , the density is ; S3, perform finite element mesh division; S301, performing finite element tetrahedral meshing on the three-dimensional geometric model of the steel ball to ensure that the mesh can accurately capture the geometric details of the steel ball; S302, converting the surface mesh into dem particles, and using the discrete element method to simulate the motion behavior of the steel ball, where each dem particle represents a steel ball; S303. Use hexahedral meshing for the shell to ensure mesh quality while adapting to the complex shape of the shell; S304. Adaptive meshing is performed on the high-pressure gas and air using the default SALE structured grid to ensure that the flow characteristics of the high-pressure gas and the interaction with the surrounding air can be effectively captured. like Figure 2As shown, the finite element model of this embodiment includes a three-dimensional geometric model of high-pressure gas 1, steel ball 2 and shell 3. The air adopts *ALE_STRUCTURED_MESH mesh, the high-pressure gas adopts *INITIAL_VOLUME_FRACTION_GEOMETRY to fill the air, and the steel ball 2 is first divided into a surface mesh using tetrahedral elements, as shown in FIG. Figure 3 As shown, then converted into dem particles; as Figure 4 As shown, the moment of inertia of the steel ball particles is calculated and discrete units are generated. The shell 3 is meshed using hexahedral units, i.e. *ELEMENT_DISCRETE_SPHERE; S4. Use *ALE_COUPLING_NODAL_CONSTRAINT_ID to simulate the contact interaction between the steel ball and the high-pressure gas to ensure that the steel ball can be accurately driven by the high-pressure gas and start to move. Use lsdyna to calculate the required information. S401, applying node constraints at the contact interface between the steel ball and the high-pressure gas to complete momentum and energy transfer; S402. Use *ALE_STRUCTURED_FSI leak-free coupling to simulate the flow of high-pressure gas inside the shell and the deformation response of the shell under the action of high-pressure gas to achieve fluid-structure coupling effect. S403, set the solution parameters, save the steel plate 2 and the shell 3 as sphere.k files and steel.k files respectively, compile the main file main.k, define all material properties, boundary conditions, initial conditions, coupling settings and other parameters, and build a complete finite element analysis model; S404, use lsdyna solver to calculate the motion and dispersion process of the steel ball driven by high-pressure gas, and set the time step to The total calculation time is 0.01s, in order to capture the transient motion process of the steel ball driven by high-pressure gas, obtain the position, velocity, acceleration, and stress and strain data of the steel ball at each moment, and obtain the motion law, distribution density and flying speed of the steel ball through analysis; After running the finite element analysis software, the calculation results were visualized and analyzed using the lsprepost post-processing tool. This generated a motion trajectory diagram, velocity-time curve, distribution density, and dispersion velocity vector diagram of the steel balls, visually demonstrating the motion patterns and distribution characteristics of the steel balls driven by the high-pressure gas. The analysis results showed that, driven by the high-pressure gas, the steel ball group exhibited a trend of uniform outward diffusion, with the velocity gradually increasing and stabilizing after a certain period of time. Statistical analysis of the distribution density and dispersion velocity of the steel balls evaluated their impact coverage and impact strength on the target material, providing a basis for optimizing the steel ball layout and high-pressure gas driving parameters. Through the simulation calculation of this embodiment, the motion process of the transient high-pressure gas-driven steel ball system can be displayed, providing reliable technical support for engineering design and scientific research in related fields, and helping to improve the performance and safety of the system.

[0012] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as above in terms of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can, without departing from the scope of the technical solution of the present invention, make some changes or modifications to equivalent embodiments using the technical contents disclosed above. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A finite element full model calculation method for transient high-pressure gas driven steel ball, characterized in that: The following steps are involved: S1. Establish a three-dimensional geometric model of the steel ball, including air, high-pressure gas, steel ball and shell; S2. defining the material properties of each component in the three-dimensional geometric model of the steel ball, including the state equation of the high-pressure gas, the elastic modulus and Poisson's ratio of the steel ball, and the tensile strength, yield strength, and Poisson's ratio of the shell; S3, perform finite element mesh division; S301, performing finite element surface meshing on the three-dimensional geometric model of the steel ball; S302, converting the surface mesh into dem particles, and simulating the motion behavior of the steel ball using discrete element method, where each dem particle represents a steel ball; S303, using hexahedral meshing for the shell; S304, adopt the default SALE structured grid for high pressure gas and air; S4. Use *ALE_COUPLING_NODAL_CONSTRAINT_ID to simulate the contact interaction between the steel ball and the high-pressure gas, and calculate the required information through lsdyna; S401, applying node constraints at the contact interface between the steel ball and the high-pressure gas to complete momentum and energy transfer; S402. Use *ALE_STRUCTURED_FSI leak-free coupling to simulate the flow of high-pressure gas inside the shell and the deformation response of the shell under the action of high-pressure gas. S403. Set the solution parameters and use the LSDyna solver to calculate the motion and dispersion process of the steel ball driven by high-pressure gas. The position, velocity, acceleration, and stress-strain data of the steel ball at each moment are obtained through LSPrepost processing. The motion law, distribution density, and dispersion velocity of the steel ball are obtained through analysis.

2. The method for calculating a finite element full model of a transient high-pressure gas-driven steel ball according to claim 1, characterized in that: The high-pressure gas cavity of the steel ball three-dimensional geometric model uses *INITIAL_VOLUME_FRACTION_GEOMETRY to fill the complex structural model.

3. The method for calculating a finite element full model of a transient high-pressure gas driven steel ball according to claim 1, characterized in that: The state equation of the high-pressure gas in the three-dimensional geometric model of the steel ball adopts the ideal gas state equation, which is expressed as follows: ； in, represents the gas pressure, represents the volume of gas, represents the amount of gaseous substance, represents the ideal gas constant, Indicates the gas temperature; The steel ball adopts the rigid material constitutive model, and the elastic modulus , Poisson's ratio ; The shell is made of *MAT_PLASTIC_KINEMATIC material, with tensile strength , yield strength , elastic modulus , Poisson's ratio .

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