Weld characteristics of non-axisymmetrical butt welded branch pipe T-joints using finite element simulation and experimental validation

The weld characteristics of non-axisymmetrical butt welded branch pipe T-joints are rarely investigated experimentally and numerically. For the safety assessment of such weld joints, critical importance to be given for the estimation of magnitude and distribution of residual stresses. Initially, a three dimensional finite element (FE) model is developed to simulate the GTAW process using SYSWELD for joining the different cases of AISI 304L branch pipe T-joints. During simulations, a sequentially coupled thermo-metallurgical-mechanical analysis is performed to study the temperature and weld induced residual stress distributions. Significant differences in 3D temperature profiles, temperature distributions and residual stress states are noticed between run and branch pipes for different pipe sizes along different sections. Also, the accuracy of the developed FE simulation strategy is validated for transient temperature distributions and residual stress fields through full-scale shop floor welding experiments.