Dependence of the representative strain on the hardening functions of metallic materials in indentation

We extended the representative strain defined by Dao et al. [M. Dao, N. Chollacoop, K.J. Van Vliet, T.A. Venkatesh, S. Suresh, Acta Mater. 49 (2001) 3899] from power law materials to linearly hardening and Voce-type hardening materials. The results reported herein highlight the extent to which the representative strains defined in the literature depend on the hardening functions of metallic materials. Moreover, they can be used to develop inverse approaches to determine the plastic properties of the metals whose plastic behaviour can be described using a linear or exponent function.