Indentation and imprint mapping for the identification of material properties in multi-layered systems

Multi-layered thin films have become popular thanks to their ability to enhance the performance, stiffness and strength of a component. In order to verify that the above properties are achieved in a production process, it is necessary to have reliable techniques to measure the mechanical parameters of such systems. Indentation tests are frequently employed for the identification of material parameters at different scales. In this context, this paper presents an inverse analysis technique which combines the indentation curve with the imprint geometry for the identification of the mechanical parameters of two alternating elasto-plastic hardening materials placed through the thickness of multi-layered systems. Three indentation-based inverse analysis methodologies are proposed for the identification of the sought material properties. Inverse analysis procedure consists of a batch, deterministic approach, and conventional optimization algorithms are employed for the minimization of the discrepancy norm. Extensive numerical computations have been performed in order to test the performance of the proposed methodologies in terms of result accuracy and computational effort.