Inverse analysis and DIC as tools to determine material parameters in isotropic metal plasticity models with isotropic strain hardening

The main objective of this study is to estimate the accuracy of the method for the determination of material parameters based on laboratory data from a single experiment conducted on a sample working in a nonuniform stress state, registered by the digital image correlation system (DIC). The idea of the method is based on the inverse analysis, in which the material parameters are determined by the optimization procedures using the cost function being the result of comparison of the laboratory data with the results of FEM simulation, wherein the whole deformation areas are taken into account. This paper presents the method described above applied on the determination of isotropic hardening parameters for an aluminum alloy material. Tests were carried out on the aluminum plates with nonuniform geometry subjected to tensile deformation. A comparison of the effect of sample geometry on the results was made, and an analysis of the impact of variation of material parameters on the value of the cost function was carried out.