Residual Stress Distributions for Plate T-Butt Welds in Defect Assessment Applications

The residual stress distributions for plate T-butt welds were determined from a detailed finite element analysis of the welding process and they were compared with those of the measured data for validation. The residual stress distributions from the analyses and measurements were shown to be in similar shape. The distributions were found to be below the master curve for the residual stresses that were previously determined from a statistical analysis for a range of weld geometries and materials. A failure assessment for the T-butt weld with cracks under residual stress distributions has been carried out. The conservatism in the current life assessment procedures regarding the residual stresses were quantified based on the stress intensity factor (SIF) calculations for the T-butt weld. It was shown that the master curve profile provides more realistic values for the SIFs with reasonable conservatism than the profiles recommended in the existing assessment procedures.