FEM evaluation of strain release coefficients of blind-hole technique related residual stress measurement

The measurement results of blind-hole technique are greatly affected by strain release coefficients. The traditional methods to get strain release coefficients are to do assignment test in laboratory, but it is a time-cost work. In order to explore a simpler and more accurate method to calculate the strain release coefficients A and B of blind-hole technique, finite element model of three dimensions was created. Correctional formulae to relate the strain release coefficients to the energy parameter S was obtained according to the FEM analysis results. It can greatly improve the measurement results by using the strain release coefficients calculated from the correctional formulae to calculate the residual stress. This new method can save time and money and has very important application value.