Welding-induced stresses and distortion in high-strength steel T-joints: Numerical and experimental study
Mehran Ghafouri, Antti Ahola, Joseph Ahn, Timo Björk
Abstract
The main objective of this study is to develop a computational approach based on the finite element (FE) method to efficiently predict welding deformations and residual stresses of fillet welded T-joints made of high strength steel (HSS), S700, using different welding sequences and external constraints. With this aim, thermo-elastic-plastic FE models were developed in ABAQUS FE code based on Goldak's double ellipsoidal heat source model, material non-linearity and geometrical non-linearity. The results of the FE models in terms of temperature fields, angular distortion and transverse residual stress were verified against measurements. The results showed that angular distortion and transverse residual stress were significantly impacted by configuration of the external constraints, while longitudinal stress were less affected. It was found that the welding sequences had a smaller effect on the sequential and cumulative welding distortions and final residual stresses than the configuration of the external constraints. The results of this study are meaningful for understanding of the calibration and accuracy of FE computational approaches to simulate welding processes. Additionally, from a practical point of view, the results are important to understand the distortions and residual stress control measures of structural members made from HSSs.