A CRITICAL INVESTIGATION OF THE UNLOADING BEHAVIOR OF SHARP INDENTATION

Finite element simulations of the indentation of rigid indenter into a n elastic-plastic half space have been conducted in order to evaluate the influence of material properties on the unloading response. The em phasis of these results has been to determine the load penetration beh avior, the development of the contact area and to estimate the hardnes s and the modulus from load penetration curves. The material parameter s are chosen such that the ratio of hardness H and Young's modulus E v aries between 0.01 and 0.1. Most of these materials can be regarded as brittle. Since cracking is excluded from the analysis, the results re fer to low load penetration. (C) 1997 Acta Metallurgica Inc.