一种新型SPH-FEM耦合算法及其在冲击动力学问题中的应用

A new coupled SPH-FEM algorithm and its application to impact dynamics

为了充分发挥光滑粒子流体动力学方法(smoothed particle hydrodynamics,SPH)在处理大变形和有限元(finite element method,FEM)问题时计算精度高的优势,提出了一种新型SPH-FEM耦合算法。该耦合算法在大变形区域使用SPH粒子离散,其余区域使用有限元离散。在耦合界面处将SPH粒子固结在有限单元,在有限元节点设置背景粒子,通过背景粒子的方式将有限元节点纳入到SPH临近搜索列表,消除了SPH边界效应,确保耦合界面物理量的连续性。使用该算法对圆柱形钢弹正冲击钢板发生冲塞破坏的过程进行了三维数值模拟,靶板参数的计算采用含损伤的Johnson-Cook模型和Grüneisen状态方程,模拟结果与实验吻合较好。

The coupling of smoothed particle hydrodynamics(SPH) with the finite element method(FEM) is presented to make full use of the superiority of SPH in dealing with large deformation and the high accuracy of FEM.The coupled SPH-FEM algorithm employs SPH particles in the higher distortion regions and finite elements in the lower distortion regions.In the coupled interface,SPH particles are attached to finite elements.Background particles are assigned in the position of FE nodes,and FE nodes are added to SPH neighbor list.The boundary effect of SPH is avoided,and the continuity of the interface is guaranteed.The perforation of a cylindrical steel projectile impacting a plate target is simulated in 3D using the coupled SPH-FEM algorithm.The Johnson-Cook material model with damage effect and Grüneisen equation of state are employed for the target,and the computed results show good agreement with the experimental data.