Investigation of Interface Resolution Techniques in Moving Boundary Problems

Abstract : In this report we describe the development of a numerical solution technique for the simulation of high-speed multi-material impact. Of particular interest is the interaction of solid impactors with targets. Such interactions present the following challenges to numerical solution techniques: (1) high velocities of impact leading to large deformations of the impactor as well as the targets. (2) nonlinear wave-propagation and the development of shocks in the system. (3) Modeling of the constitutive properties of materials under intense impact conditions and accurate numerical calculation of the elasto-plastic behavior described by the models; and (4) Phenomena at multiple interfaces such as impactor-target, target-ambient and impactor-ambient. It is demonstrated that the interface can be tracked through large distortions. Accurate shock-capturing schemes can be implemented for cartesian grids and extended to incorporate the presence of the moving interfaces. Computations of the deformation process are carried to large distortions while the interfaces travel through the mesh in a stable and robust manner. The solution algorithms used in this study were developed primarily at the Air Force Research Laboratory, while the interface resolution and tracking portion of this effort was developed at the University of Florida.