Eulerian Front Tracking for Solid Dynamics

An attractive approach for simulation of solid dynamics is to combine an Euler-ian nite diierence method with material interface tracking. The xed Eulerian computational mesh is not subject to mesh distortion, and the tracking eliminates spurious numerical diiusion at interfaces and the need for mixed-material computational cells. We have developed such an approach within the framework of the front tracking method, as implemented in the FronTier code. Our two-dimensional solid dynamics code is based on a fully conservative formulation of the governing equations for large-strain deformation, a hyperelastic equation of state that allows for large volumetric change, and a rate-dependent plasticity model for high strain rates; it features conservative nite diierencing, a Riemann solver that accounts for the nonlinearity of longitudinal waves, and an implicit method for integrating the plastic source term. This paper presents an overview of the FronTier-Solid code and some preliminary applications to high-velocity impact and shock-accelerated interface problems. 1. Introduction The simulation of dynamic material failure and fragmentation, such as occurs during ballistic impact loading 27], is an important challenge for multi-scale science. From this point of view, individual microstructural features (e.g., grains, ductile voids, brittle cracks, and adiabatic shear bands) are the elementary modes whose collective evolution at the mesoscale leads to macroscale dynamic failure. Through study of these elementary modes, both by analysis and simulation, multi-scale methods eeect a coarse-graining to the macroscale. This approach ultimately yields continuum models, suitable for use in system-level simulation codes, which incorporate the integrated eeects of the evolving material microstructure. Direct numerical simulation, in which relevant microstructural features are explicitly represented in the computational domain, is critical to the success of multi-scale modeling for dynamic failure in solids. Moreover, because such simulations are used in the construction