Identifiability of single crystal plasticity parameters from residual topographies in Berkovich nanoindentation on FCC nickel
Résumé
The information richness of imprints topographies obtained after Berkovich nanoindenta- tion tests at grain scale is assessed for identifying all or part of the parameters of a sin- gle crystal plasticity law. In a previous paper (Renner et al., 2016), the strong potential of imprints topographies has been shown through a large experimental campaign con- ducted on nickel samples. A 3D crystal plasticity finite element modelling (CPFEM) of the nanoindentation experiment using the Méric-Cailletaud has also showed a large sensitivity of residual topographies to the indenter/grain orientation and to the plastic parameters, including the interaction matrix coefficients specifying the interactions between disloca- tions on different slip systems. This makes imprints topographies very good candidates to provide information for the single crystal parameters identification. The present paper fo- cuses on the Méric-Cailletaud law parameters identifiability using residual topographies. A method is built to define the best well-posed inverse problem to ensure the parame- ters identification using a crystal plasticity finite element modelling updating (CPFEMU) method. An identifiability index proposed by Richard et al. (Richard et al., 2013) for mea- suring the information richness of the indentation curve is extended to the analysis of residual topographies. This index quantifies the possibility to achieve a stable/unstable so- lution using an inverse method. For the studied behaviour, the results show that eight of the nine Méric-Cailletaud law parameters can be identified using three topographies.
Domaines
Mécanique [physics]Origine | Fichiers produits par l'(les) auteur(s) |
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