Development of an Optimized Loading Path for Material Parameters Identification

Abstract

Nowadays, the characterization of material is becoming increasingly important due to ma\-nu\-fac\-tu\-ring of new materials and development of computational analysis software intending to reproduce the real behaviour which depends on the quality of the models implemented and their material parameters. However, a large number of technological mechanical tests are carried out to characterize the mechanical properties of materials and similar materials may also have properties and parameters similar. Therefore, many researchers are often confronted with the dilemma of what should be the best set of numerical solution for all different results. Currently, such choice is made based on the empirical experience of each researcher, not representing a severe and objective criterion. Hence, via optimization it is possible to find and classify the most unique and distinguishable solution for pa\-ra\-me\-ters identification. The aim of this work is to propose a methodology that numerically designs the loading path of multiaxial testing machine to characterize metallic thin sheet behavior. This loading path has to be the most informative, exhibiting normal and shear strains as distinctly as possible. Thus, applying Finite Element Analysis (FEA) and Singular Value Decomposition (SVD), the loading path can be evaluated in terms of distinguishability and uniqueness. Consequently, the loading path that leads to the most distinguish and unique set of material parameters can be found using a standard optimization method and the approach proposed. This methodology has been validated to characterize the elastic moduli for an anisotropic material and extrapolated for an hyperelastic material.