Finite element simulation of arc welding distortion and correction in thinsidepanel sheets of a railway coach

Manual metal are welding of the thin sheet sidepanel subassemblies of a rai lway coach shell causes deformation on the exterior surface. Welding create s residual stresses and distortions because of the elastoplastic response o f the sheet to the transient, localized thermal expansion and contraction. Various strategies minimize the distortion, but a basic understanding of th e mechanism is required. The welding process has been mathematically modell ed using a general-purpose finite element code ABAQUS. The transient temper ature fields and the associated stress, strain and strain fields have been calculated by a coupled thermomechanical analysis. To improve the exterior appearance of the coach shell, a technique called the magnetic forming proc ess has been proposed. This process is designed to restore the original geo metry of the deformed sidepanel sheet. The effectiveness of this process ha s been studied in detail. The magnetic forming process, simulated to flatte n and straighten the thin sheet, is calculated to yield good results.