MATERIAL POINT METHOD SIMULATIONS OF THERMOBARIC WARHEAD MATERIALS

LCDR Konstantinos Elefttheriou, HN

We consider the ballistics and fragmentation of reactive materials following high velocity impact on thin targets. We have simulated the impact of a brittle, reactive aluminum fragment onto a thin steel plate to compare with recent Navy experiments. We use the Material Point Method (MPM) within the Uintah hydrocode; this technique is a partially mesh-free method which is promising for the severe deformation that occurs during high velocity brittle impact. We have developed a material model for the brittle aluminum based on limited experimental data, and use standard material models to treat the steel targets. A range of impact velocities and geometries were simulated to mimic the conditions of standard tests on thermobaric fragments. In order to validate our model, the simulation results are compared to the data taken from recent Navy experiments involving the firing of spherical reactive material pellets through a thin steel plate. We compare the sphere dimensions, residual velocity, and resulting debris cloud in our simulations to flash x-ray and high speed videography from the events, and find good agreement at velocities above the ballistic limit.