Probing out-of-plane anisotropic plasticity using spherical indentation: A numerical approach

An evaluation method for out-of-plane anisotropic plastic properties is proposed using single spherical indentation. For a plastically anisotropic material, whose properties (i.e. yield stresses) are different among orthogonal directions (e.g. in-plane vs. out-of-plane direction), the proposed method is shown effective for distinguishing the anisotropic properties. Upon spherical impression, the indentation curves are dependent on plastic anisotropy (i.e. the yield stress ratio in different directions). By bridging the indentation response with impression geometry through extensive finite element analyses, dimensionless functions are established in order to deduce anisotropic plastic properties. The effectiveness of the method was investigated by numerical experiments. The validity and future issue were discussed.