Estimation of residual stress and plastic properties of a material without plastic plateau by using continuous spherical indentation

This paper presents a method to allow the measurement of residual stress (σr ), yield strength (σy ) and strain hardening exponent (n) of metal materials through continuous spherical indentation test. Based on the analysis of finite element simulation results, a new fitting equation between the indentation response parameter and the material properties was given. The influence of friction on finite element model simulation was also discussed when the residual stress is included in the material. Only three load values are required at each different indentation depths, and the three unknown parameters (σr, σy and n) can be obtained through corresponding dimensionless functions. Finally, the validation of the method presented in this paper was verified by simulating the material (SUS304) with the known material parameters in the literature. © 2019 Trans Tech Publications Ltd, Switzerland.