ON THE DETERMINATION OF RESIDUAL STRESS AND STRAIN FIELDS BY SHARP INDENTATION TESTING

摘要

Sharp indentation tests, presently represented by cone and Vickers indenters, are analysed theoretically and numerically in order to explore how equl-biaxial residual stress and strain fields can be determined from the global properties, i.e. the size of the contact area between indenter and material and the hardness, given by such tests. It is shown that the residual Strain fields can be accurately correlated with the hardness value while residual Stresses are related to the size of the contact area. The latter feature is explained by the fact that the size of the contact area is sensitive to elastic effects. The results are summarized in simple closed form relations, well-suited to be used in an experimental Situation, and the range of validity for the resulting formulae is discussed. The predictions are compared with corresponding results taken from the literature and good agreement is found. An experimental scheme for determination of residual fields by indentation is also suggested.