Design sensitivity analysis for transient explicit dynamic response of elasto-plastic shell structures

Computational strategy for the design sensitivity analysis (DSA) in finite-element explicit dynamic computations of elasto-plastic shell structures is presented. The formulation of the primary problem includes fully nonlinear finite-rotation shell kinematics and a large-deformation constitutive model based on the elastic-plastic split of the deformation gradient. Associated flow rule with nonlinear hardening is adopted. Design derivatives are determined analytically for a class of design parameters consisting of the input material constants of the constitutive model. Design-differentiation of the primary algorithm is presented with a number of possible simplifications indicated. Despite a great complexity of the solution algorithm for the finite-rotation elastic-plastic shells, it is feasible to compute analytical design derivative of this algorithm, and the yielded sensitivities are of very good accuracy.