Variational Methods for Design Sensitivity Analysis of Nonlinear Response with History Dependent Effects

In this paper, general sensitivity analysis for structural systems with nonlinear response is developed. Both geometric and response history dependent material nonlinearities are considered. A variational formulation unifying the conventional and shape design problems is employed. Two approaches for sensitivity analysis, i.e., the direct differentiation and the adjoint structure, are developed. The difficulties associated with nonlinear sensitivity analysis and relative advantages and disadvantages of the two approaches are discussed.