Simulation of hypervelocity-impact debris clouds using a Lagrange FEM with node separation

An improved Lagrange finite element method was proposed for impact fracture anaylysis, in which the node separation technique was used to achieve mesh separation and the distortion erosion method was applied to deal with seriously distorted elements. By applying the LS-dyna solver, a C++ program was developed to establish the computational model for the node separation and implement the distortion erosion. The C++ program was combined with the LS-dyna restart analysis function to achieve fracture analysis. A hypervelocity impact problem was simulated by the node-separation Lagrange FEM and SPH mesh free method, respectively. And the simulated results were compared with the existing experimental results and the Euler EFM results. Comparison shows that the node-separation Lagrange FEM takes the advantages of fast calculation, good stability, and clear boundary, and it can be used to accurately and effectively simulate hypervelocity impact problems.