Identification of the matrix of interaction by nanoindentation – NOTIFICATION

Advances in numerical simulation allow most real mechanical tests to be replaced, completed or prepared by virtual tests. It is now necessary to take into account the interactions between crystal defects, which requires the identification of many parameters in the continuum mechanics framework. The analysis of the residual topography obtained after nanoindentation test is a very promising way to address this challenge. Intra-grain residual stress and disorientation fields induced by indentation are probably also very rich information for understanding these interactions between crystalline defects. Given the complexity of the crystal plasticity laws, of the Berkovich indentation and the variety of observables offered by modern microscopy, designing the experiments to well pose the plastic parameters identification problem using Crystal Plasticity Finite Element Model Updating (CPFEMU) method is challenging.
The envisioned approach consists in numerically design the optimal Berkovich indentation experiments on single crystals (Cu & Ni) using a parameterized simulation model. This involves looking for combinations of tip/crystal orientations and sections plane for HR EBSD (observations that contain information relevant to the identification of parameters of interest.
So-designed experiments will then be performed at indentation depths larger than one micrometre to avoid scale effects. The CPFEMU method will then be implemented. The ability of the developed method to capture new information on the crystalline plasticity of materials more complex than recrystallized Cu and Ni will then be explored.