Numerical Modeling of Spallation Experiments of Tantalum

A phenomenological model, which includes nonlinear elasticity (equation of state), rate-dependent plasticity, and void nucleation and growth, is provided for modeling the spallation behavior of tantalum. An implicit numerical technique, diagonally implicit Runge-Kutta method, is used to solve the constitutive rate-equations, and some improvements to the stability and accuracy of the solution are obtained. The model developed is used to simulate the plate impact experiments on tantalum. Comparisons are made between the model and the experimental data. Results show that close agreement between model predictions and experimental results is obtained for moderate or high velocity plate impact experiments, but some improvements in the model are necessary to predict the damage evolution and failure in incipient spall fracture of tantalum.