Finite Element Prediction of Residual Stresses in a Fillet Welded T-joint

摘要

Welding-induced residual stresses and distortion can play a very important role in the reliable design of welded joints and welded structures. However, general simple methods for the prediction of the distribution and magnitude of residual stresses are not available from the literature. A reliable and efficient numerical analysis of this complex phenomenon can thus be considered as the only feasible alternative. A finite element (FE) simulation of a sequential fillet welding process producing a T-joint is presented in this paper. The main features of the essentially 2D analysis are ramped heat input function, temperature-dependent material properties and element death and re-birth technique. A parallel experimental investigation allowed the assessment of plastic properties variations in the welding area. Temperature history and welding-induced distortion data from tests were compared to the results from the FEM simulation for calibration and validation purposes. The validated model can be used to study the sensitivity of its predictions to variations of parameters such as heat input, material properties, radiation and fit-up. The final objective is to establish a reliable and versatile analytical tool for obtaining not only qualitatively but also quantitatively the welding-induced residual stresses and distortion. This information is essential to both researchers and designers for assessing the failure behaviour of welded joints and structures.