A new spherical indentation-based method to extract plastic material parameters

This paper presents a new spherical indentation-basedmethod to extract plastic properties of materials. With the specificevaluation on the response parameters in indentation tests, the energy ratio(the ratio of releasable work to total work) was chose and investigated inorder to avoid the estimation of contact radius. Based on expanding cavitymodels, finite element computations and dimensional analysis, therelationships between energy ratio and plastic parameters are established.With these relationships, the plastic properties of materials can beconsequently solved from instrumented spherical indentation test data.Furthermore, the stability of the method has been improved by reorganizationof parameters. Finally, the veracity and simplicity of this method ischecked by using two typical materials (Steel 45C and Al 6061), which haveknown true stress-true strain curves.