A New Approach to Improve Material Models

Abstract

The inelastic behavior of materials is described most efficiently by unified models when their material functions are determined so that flow, hardening, creep etc. will be covered correctly. In this paper, the adaptation of a model is not confined to finding the optimal material parameters but is extended to the identification of the optimal shape of the material functions itself. Material functions given by series of simple shape functions defined in discrete sections which merge smoothly together lead to the best adaptation to experimental results. Furthermore, any remaining shortcomings of the model reveal deficiencies in the modelling of the microphysics of the material. Then by careful interpretation of the uncovered physical properties the original material model has to be amended leading to the derivation of even entirely new models. Thus, a powerful tool is presented here by which a unified model can be checked and improved.