An Ultra Low-Cost FEM Procedure to Predict the Welding Distortions and Residual Stressesof Two Thick-Walled Butt-Welded Pipes

Welding is a significant manufacturing method, which iswidely used in various industries such as shipbuilding,and automotive, and also rails and bridges. Generally,welding distortions cause problems such as dimensionalinaccuracies during assembly process, which results in anincrease in production costs. Therefore, prediction andreduction of welding distortions are necessary forimproving the quality of welded structures. Generally, athermo-elasto-plastic analysis is used to estimate weldingdistortions and residual stresses, which is a timeconsumingprocess. In this work, an elastic FEM analysisbased on the inherent strain theory is used to quickly andaccurately predict the distortions of a butt-welded joint oftwo thick-walled pipes. First, a thermo-elasto-plasticFEM analysis is performed to estimate the inherentdeformations of the weld. Then, based on the inherentdeformations, the proposed elastic FEM analysis isperformed to predict the welding distortions and residualstresses. Using this procedure, the calculation time ismassively dropped, due to the fact that the proposedmethod is an elastic static analysis, while the thermoelasto-platic method consists of two transient analyses.