Numerical analyses of the influence of tack welding on angular deformation using the finite element method

Abstract

Welding is a fundamental process in the fabrication of structures in various engineering fields. However, imperfections caused by the process can compromise the structural integrity and service life of the components. During the fabrications of structures by welding, tacks welds are applied to avoid over-constraint of the structures. However, the lack of standards for this process could cause an increase in angular deformation. This study focuses on investigating the effect of tack welding on structural stiffeners. A Thermo-Elasto-Plastic Analysis (TEPA) using the Finite Element Method (FEM) is employed to simulate the shielded metal arc welding process applied on S355J2 steel structural stiffeners used in the bow and stern of small steel ships, for which different dimensions and sequences of tack welding are considered. On the other hand, a parametric analysis of the finite element size in the heat-affected zone (HAZ) is carry out, to determine an optimal model for this study. The results show that the angular deformation, considering the recommended dimensions and sequences of tack welds, increases by 8% compared to the model that does not consider tack welds. Based on the results, dimensions and sequences of tack weld are recommended that can be applied in the field, which could mitigate the angular deformation on the structural stiffeners.