Innovative Lagrangian Numerical Approach for Natural Fragmentation Modeling

Abstract

Numerical modeling of fragmentation from dynamic loading has traditionally been modeled by legacy finite element solvers that rely on element erosion to model material failure. However it results in too much material removal which is not realistic as retaining the structure mass is critical to modeling the event correctly. We propose a new approach implemented in the IMPETUS AFEA SOLVER® based on: New High Order Finite Elements (very well suited for large deformations); stochastic distribution of initial damage (non-homogeneous distribution of fragments); a Node Splitting Algorithm (material fracture without element erosion) and a new particle method for High Explosive modeling. The approach is evaluated for various scenarios: beam and thin cylinder bending, ring compression and warhead natural fragmentation. The results obtained from the simulations are representative of the failure mechanisms experimentally observed. The main benefits of this approach are good energy conservation and numerical robustness even in complex situations.