Finite element model based elastoplastic contact model and some aspects on indentation response

Indentation tests are useful in evaluating the response of materials. They can be applied to determine the mechanical properties of bulk materials, thin films and coatings. Control of some factors that affect the test and the resulting property evaluation is important. Finite element model based elastoplastic contact analysis of a spherical indenter on a flat half space has revealed some interesting behaviours, which highlight certain limitations associated with the response. Under elastoplastic behaviour, it is observed that the constraint factor value sometimes defies the limit set for the validity of the analysis, and the variation is sensitive to yield strength, with a decreasing effect on the critical depth of deformation. Failure to acknowledge such effects will lead to erroneous evaluation of the response. The present work highlights the observations of the numerical simulation results and some experimental data on static indentation response evaluation of metallic and sprayed ceramic composite coatings.