A unified approach for parameter identification of inelastic material models in the frame of the finite element method

This work is concerned with identification of parameters for inelastic material models. In order to account for possible non uniformness of stress and strain distributions, the identification is performed in the frame of the finite element method. In particular, linearization procedures are described in a systematic manner for he case of complex material models within a geometric linear theory. This unified approach allows one to apply the Newton method for solving the associated direct problem and to apply gradient based methods for solving the associated inverse problem, which is considered as an optimization problem. Two numerical examples demonstrate the versatility of our approach: firstly, we consider Cooks membrane problem based on simulated data for re-identification of material parameters for a viscoplastic power law. Furthermore, material data for J(2)-flow theory are determined, based on experimental data obtained by a grating method for a compact specimen, and we will investigate the results by using different starting values and stochastic perturbation of the experimental data.