A NEW COMBINED PARTICLE-ELEMENT METHOD FOR BALLISTICS COMPUTATIONS INVOLVING HIGH-VELOCITY IMPACT

This article presents a Combined Particle-Element Method (CPEM) for 3D ballistics impact computations. It is an extension of recently reported work in 2D geometry. It includes a description of the numerical algorithms and example computations. The advantages of this method are that the lower-strained particles (stress points) are computed with a fast and accurate finite-element formulation, and the higher-strained particles are computed with a meshless-particle formulation that can handle severe distortions. Furthermore, the meshless-particle algorithm (with MLS strain rates and weak-form forces) is consistent and does not exhibit tensile instabilities. It is also well suited for conversion of finite elements into variable-connectivity meshless particles because it does not require deletion of elements and addition of particles. Instead it is simply a branch point based on equivalent plastic strain. The basic approach can also be used for the element algorithm only or the particle algorithm only.