An effective inverse analysis tool for parameter identification of anisotropic material models

• Anisotropic elastic–plastic-hardening model defined by 7 independent parameters.
• Indentation test performed according to Rockwell standards.
• Identification procedure based on combined experimental–numerical procedures.
• Computations based on reduced analytical models.
• Extensive exploration over a large range of parameter values and large anisotropy ratios.

Effective inverse analysis tools rest on the synergetic combination of even complex experimental and numerical procedures. This is the case of methodologies recently developed for the identification of parameters entering anisotropic elastic–plastic constitutive laws on the basis of data collected from indentation tests. The values of the sought material properties are inferred from a discrepancy minimization procedure, which entails the repeated simulation of the test. In this situation, the overall computing burden can be significantly reduced, without compromising the accuracy of the results, replacing traditional finite element approaches by approximated analytical models, based on the interpolation by radial basis functions of a few numerical results filtered by proper orthogonal decomposition. The effectiveness of this technique is demonstrated in the present study with specific reference to earlier investigated elastic–perfectly-plastic materials and is further verified on the more general case of hardening constitutive models. The accuracy of the identification results and the role of the likely occurrence of multiple solutions are discussed.