Probing Constitutive Models of Bohus Granite with In Situ Spherical Indentation and Digital Volume Correlation

Abstract

Spherical indentation of granite was investigated using Digital Volume Correlation (DVC) aiming at probing constitutive laws of the studied rock. In situ indentation was performed within an X-ray tomograph. Finite element simulations of the problem, using different constitutive models, were carried out and their trustworthiness was assessed thanks to DVC residuals. Three laws were investigated, namely, pure elasticity, then compressible elastoplasticity, and finally compressible elastoplasticity coupled with damage. Frictional contact effects were studied as well. The results show that compressible elastoplasticity should be accounted for to achieve high accuracy of results, and that frictional effects are of importance in terms of damage extent. If macrocrack initiation is also sought, then damage features should be included in the model.