Numerical sensitivity study of ballistic impact on UHMWPE composites

In recent years, ultra-high molecular weight polyethylene (UHMWPE) composite materials have frequently been in the spot-light of investigations for protective applications. As a result, a state-of-the-art material model with a material-characteristic discretization scheme was developed that enables a wide range of high-velocity impact simulations in hydrocodes [1, 2]. In particular, the back face deformation and the V50 for impact velocities above 800 m/s are reported to be well predicted when compared to ballistic impact experiments. In this study, the numerical model is applied to investigate key parameters such as sample size, strength in fiber direction and normal and shear cohesion of the bonding interfaces with regard to their influence on the back face deformation. The main part of this study is concerned with a standard 100 % crosswise layup. Chosen results for a laminate that has the back 25 % of sub-laminates helicoidally oriented with a 22.5° sequence, similar to the so-called ARL-X layup presented by [3], are compared to the results from the standard layup.