An Analysis Procedure for Predicting Weld Repair Residual Stresses in Thick-Walled Vessels

Abstract

An analysis procedure for computing residual stresses due to weld repairs of heavy steel sections is described and illustrated. The model has several unique features for weld repair applications. These include a simple formula for computing temperatures in and near the repair region, a method for economically modeling the application of hundreds of weld passes typically required in repairs, and a method by which the basically two-dimensional residual stress analysis model can be inexpensively modified to incorporate some three-dimensional effects. Laboratory data for residual stresses due to the weld repair of a flat plate and computed values for a curved plate are compared. Good qualitative agreement is found. Next, the computational model is used to predict residual stresses due to a weld repair in one of the Heavy Section Steel Technology Intermediate Test Vessels. Residual stress data available for this vessel are compared with predicted values of residual stress. There is good agreement between the computed values and residual stress data for regions outside of the weld repair. A discussion of the overall agreement is given. This study demonstrates that it is economically feasible to predict the complex behavior of weld repair residual stresses.