An expanding cavity model incorporating pile-up and sink-in effects

A new expanding cavity model (ECM) for describing conical indentation of elastic-ideally plastic material is developed. For the proposed ECM, it is assumed that the volume of material displaced by the indenter is equal to the volume loss, due to elastic deformation, in the material and depends on the pile-up or sink-in. It was shown that the proposed ECM matches very well numerical data in the final portion of the transition regime for which the contact pressure lies between approximately 2.5Yand 3Y. For material of largeE/Yratio, the new ECM also provides results which are very close to the numerical data in the plastic-similarity regime (regime in whichCf= 3). For material of smallerE/Yratio, the proposed ECM gives better results than the Johnson’s ECM because pile-up or sink-in is taken into account.