Development of an improved energy-based method for residual stress assessment

In this study, an improved energy-based method is proposed to measure the equi-biaxial residual stress of bulk materials using spherical indentation. Through analysis of the load–depth curve and residual indentation profile, two calculation methods of the energy of residual stress are proposed, one of which is determined from the load–depth curve and the other based on the Hertizan theory. Finite element analysis was used to establish their relationship, which is the function of the residual stress and material parameters. According to reverse analysis, the proposed method can be used to quickly and effectively determine residual stress. To verify the model, indentation experiments were performed using a ZHU0.2/Z2.5 testing machine. A comparison with conventional X-ray diffraction results showed that the improved method is suitable for the quantitative assessment of residual stress in industrial facilities.