Influence of welding sequence on welding deformation and residual stress of a stiffened plate structure

Abstract

An important consideration in the safe and efficient manufacture and operation of marine structures is the possible distortion, and consequential induced residual stress, owing to welding. This paper deals with welding simulation of a stiffened plate structure with longitudinal and transverse stiffeners using a thermal elasto-plastic FE method. Shell elements with section integration features are adopted to model the plate and stiffeners and solid elements to model the local detail of weld line region. Linear constraint equations are established between degrees of freedom of the shell and solid elements. Welding parameters of heat input, welding speed and welding sequence are considered in the analysis. A typical fillet-welded joint is studied and the thermal and mechanical results are compared with experimental values. Six welding sequences are simulated. The results demonstrate the specific influences of the different welding parameters on residual distortion and stress in a stiffened plate structure.