The Influence of Mechanical Constraint on the Welding Deformation of a Large-scale Ship Bottom Grillage

摘要

Based on thermal elasto-plastic finite element method (FEM), thewelding simulation of a large-scale ship bottom grillage was carried outin this paper. The structure comprises five transverse floors and threelongitudinal girders. In order to enhance modeling and calculationefficiency, shell elements with section integration are adopted to modelthe entire structure and solid elements to model the local details of weldline region. Linear constraint equations are established between degreesof freedom of shell and solid elements. The techniques of segmentedmoving heat source model and static substructure are adopted in orderto reduce the computation time of models. Some key weldingparameters such as heat input, welding speed and welding sequence areconsidered in the analysis. The welding deformations under twodifferent constraints, including global bending, transverse angulardistortion and torsion distortion, are analyzed and compared in thispaper.