Numerical simulations of ceramic target subjected to ballistic impact using combined DEM/FEM approach

Abstract

Ceramic materials have great mechanical and functional properties. They combine low density, high hardness and strength in compression. However, ceramics is inherently brittle and there is a considerable problem to predict the strength and overall behaviour of the material subjected to high-velocity impact. In this article, we consider new modification of Discrete Element Method implemented in LS-DYNA code to simulate 6.35 steel ball impact on alumina ceramics. Discrete rigid spheres in this method linked together through truss-like bonds that allows to simulate linear-elastic solid material behaviour. After breaking of bonds, particles continue to interact with each other and with any structure by using standard DEM algorithm. Model calibrations based on the data obtained from biaxial strength tests and material elastic constants were performed. Calculated residual velocities were in a good agreement with experimental ones. With a minor additional calibration, the approach will allow to obtain realistic fragmentation of ceramic target and can be a useful tool for analysis of brittle solid behaviour during static and dynamic loading.