A 3D explicit FEM package has been developed to analyze the deformation and failure process of materials under impact loading. The package is constituted of a finite deformation plastic model, a frictional contact algorithm, an adaptive meshing capability, and a module of dynamically inserted cohesive elements to simulate dynamic crack propagation. In this paper, we present three simulations that investigate dynamic crack propagation in a metallic and a ceramic material. The quantitative and qualitative agreements between experimental and simulation results are discussed.