Sensitivity analysis for failure and damage in dynamically loaded tensile bars (Q1267916)

We present computational procedure for evaluating the sensitivity coefficients of porous viscoplastic solids under dynamic loading. The effects of finite strains, material strain and strain-rate hardening, and the thermal softening due to adiabatic heating are incorporated into the formulation. A critical void volume fraction criterion is used to identify the initiation of failure. The equations of motion emanating from a finite element semi-discretization are integrated using an explicit central difference scheme. First- and second-order sensitivity coefficients of the response quantities (derivatives with respect to various material parameters) are evaluated using a direct differentiation approach in conjunction with an automatic differentiation software facility. Finally, we present numerical results for tensile specimens subjected to impact loading.