Numerical sensitivity studies of a UHMWPE composite for ballistic protection
Ultra-high molecular weight polyethylene (UHMWPE) has a high potential for ballistic armor applications due to the excellent weight specific strength inherent to this type of material. In this paper, a non-linear orthotropic material model for the UHMWPE, based on the product DYNEEMA® HB26, is used for assessing the influence of the material properties on the ballistic performance. The model, implemented in the commercial hydrocode ANSYS AUTODYN uses initially linear-orthotropic elasticity, subsequent non-linear strain hardening, multiple stress-based composite failure criteria and post-failure softening. The strength model is coupled with a polynomial equation of state. An experimentally supported material data set for UHMWPE, presented before, is used as a baseline for the numerical studies on high velocity impact. Parameter sensitivities are studied for these impact situations. The numerical predictions are compared to available experimental data over a wide range of impact velocities (1 km/s up to 6 km/s). The objective of this paper is to assess the influence of different material parameters on the predictive capability of high velocity impact simulations and subsequently provide guidelines for the required experimental characterization of UHMWPE under shock loading.