Parameter Identification of a Plastic Damage Model

Abstract

Studies on parameter identification of a plasticity-based damage constitutive model for concrete are presented in this paper. Differences between the stress-strain curves experimentally obtained and the ones numerically obtained at local level were used as the objective functional of a regularized least square method. For solving the inverse problem, the solution of the direct problem at local level obtained by a driver subroutine was embedded in the iterative solution procedure for the inverse problem proposed in this paper. The sensitivity matrix was calculated numerically by the finite difference method. Numerical examples are given for fitting the numerically obtained stress-strain curves on to a set of experimental results. Parameter identifications under various loading cases, which include uniaxial extension and triaxial compression with different confining stresses, were performed. Results indicate that the numerical scheme is stable and has reasonable accuracy.