Plastic properties determination method for power-law hardening material using plural triangular pyramid indenters

Abstract

A determination method for elastic-plastic material constants that obey the power-law hardening rule, from a couple of sharp micro-indentation tests, is proposed. Based on a similarity function that is determined from the three-dimensional FE simulation, it is shown that for plural triangular pyramid indenters with different apex angles unique values of representative strain correspond to each apex angle. It is also shown that Π versus E*/σr, plot, which is constructed from FE simulation result, can be expressed as an interpolation between two analytical extremes: the elastic solution and the rigid/perfectly plastic solution. Based on these results, we propose a new method for determination of power-law hardening material constants, utilizing two triangular pyramid indenters with different apex angles. A simple method for determining the value of representative strain is also proposed.