Influence of sample thickness and experimental device configuration on the spherical indentation of AISI 1100 steel

Abstract : Most instrumented indentation theoretical studies and models consider bulk sample geometry, which implies no influence on the indentation response. In the particular case of thin samples, our previous studies have shown that the thickness has an influence on the experimental device behaviour as well as on the sample and material response. This work is a numerical and experimental illustration of this particularity. Spherical macroindentation tests are performed on AISI 1100 steel samples of thicknesses varying from 10 to 0.55 mm. Experimental and numerical results are compared. Experimental limitations are investigated and solutions to obtain results which are independent of the sample thickness and curvature are proposed. We show that the proposed solution, which is the object of an international patent, leads to a reliable identification of the material mechanical properties of thin and moderately bent samples.