基于FE-SPH耦合算法的球体冲击问题研究

Study on Sphere Shock Problem Based on FE-SPH Coupling Algorithm

为充分利用SPH方法处理大变形问题与FEM方法处理冲击问题时各自的优势,提出了新型的三维SPH-FEM耦合算法,该算法在大变形区域采用SPH粒子离散,从而克服FEM方法单元畸变存在的问题,其他模拟区域使用FEM单元离散,既可以避免SPH边界效应,也能保证耦合界面物理量具有连续性。使用该算法分别对球体冲击土壤与水域的过程进行了三维数值模拟,选取含损伤的Johnson-Cook模型和Mie-Gruneisen状态方程对土壤与水域进行参数计算,对比分析球体在土壤与水域中的速度、加速度以及有效应力数据结果,分析可知,此次模拟结果与其他已有仿真结果基本吻合,验证了采用FE-SPH耦合算法处理结构与流体相互作用问题是可行和有效的,为求解流固耦合问题提供了一条崭新的途径。

In order to make full use of SPH method to deal with the problem of large deformation and FEM, the new SPH-FEM coupling algorithm is proposed in this paper. In this algorithm, SPH particle discretization is used in the large deformation area to overcome the FEM distortion problem, and FEM unit discretization are used in other simulation area, both to avoid SPH boundary effects, but also to ensure the physical continuity of the coupling interface. The three-dimensional numerical simulation of the impact of the sphere on the soil and water is carried out. The Johnson-Cook model and the Mie- Gruneisen equation of state are used to calculate the soil and water parameters, and the velocity of the sphere in the soil and water , acceleration and effective stress data are compared. It can be seen that the simulation results are in good agreement with other existing simulation results, which proves that it is feasible and effective to deal with the structure-fluid interaction problem by using FE-SPH coupling algorithm. Coupling problem provides a new way.