Theoretical Prediction of Welding Distortion Considering Positioning And the Gap Between Parts

The welding distortion of a plate structure during the assembly process is influenced not only by the local shrinkage due to the welding thermal cycle, but also by root gap and misalignment. The former is governed by the heat input. The latter is strongly affected by the welding procedure, such as the welding sequence and the restraint on the parts to be welded. In this research, an elastic FEM is developed to precisely predict the distortion during the assembly process taking these factors into account. It employs the concept of inherent strain and the interface element to account for both the local shrinkage due to welding and the gap and misalignment in the weld joint. The proposed method is applied to study the influence of the welding sequence on structure distortion during the welding assembly.