COMPARATIVE STUDIES OF DRY RING-CORE AND BLIND HOLE DRILLING BASED RESIDUAL STRESS DETERMINATION OF BUTT-WELDS

Abstract

The service life of many mechanical components is highly affected by the presence of residual stresses. 1-lence, quantifying them is very important. In this report, two commonly used semi-destructive techniques namely blind hole drilling method and ring-core method were used for measuring residual stresses. A finite element model was developed for calculating the necessary calibration coefficients of the ring-core method. Alternately regressions equations were also developed by which one could directly calculate the stresses from the strains at particular depths. Then, a comparison of the stress values obtained was made with the values obtained from the blind hole drilling technique. The over estimation of the stress values by the hole-drilling method is finally reported after validating the strain values obtained from another finite element model for hole-drilling method with the experimental data. Finally, the scope for utilizing the ring-core method for obtaining the stress profiles throughout the weld thickness is presented.