Investigating influence of external restraint on welding distortion in LAHS steel thin-plate structures by means of integrated computational approach

In order to ensure the dimensional accuracy during welding assembly, external restraints are often used to control welding-induced distortion. The objective of this study is to investigate the effectiveness of external restraints on the reduction of welding distortion in low alloy high strength (LAHS) steel thin-plate panel structures with different plate thickness by means of an integrated computational approach. In the current study, the total deformation of LAHS steel thin-plate welded structure was computed by a two-step integrated computational approach which combines the thermal elastic plastic finite element method (FEM) with the elastic FEM based on inherent strain theory. In the inte-grated computational approach, the thermal elastic plastic FEM was employed to obtain the inherent deformations of each typical joint involved in the thin-plate welded structure at the first step, and then the elastic FEM based on the inherent strain theory was used to estimate the total deformation of the whole thin-plate welded structure. Firstly, the inte-grated computational approach was used to simulate the buckling distortion in a thin-plate panel structure, and the corresponding experiment was carried out to verify its compu-tational accuracy. Then, two finite element models with plate thickness of 5 and 12 mm were established to clarify the effectiveness of external restraint on the reduction of welding distortion of the thin-plate welded structures. The simulated results suggest that external restraint could not effectively prevent the occurrence of buckling distortion for the thin-plate structure with 5 mm thickness, while it can reduce the out-of-plane deformation to a large extent for the thin-plate welded structure with 12 mm thickness.(c) 2022 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).