RESEARCH PAPER Prediction of welding sequence induced thermal history and residual stresses and their effect on welding distortion Arpan Kumar Mondal 1,2 & Pankaj Biswas 1 & Swarup Bag 1 Received: 7 September 2015 /Accepted: 3 April 2017 # International Institute of Welding 2017 Abstract Stiffened plate panel is the major structural part of a fabrication industry where fillet welding joint is one of the most important fabrication techniques. Large stiffened structures are generally joined by several welding passes which generates ther- mal stresses and angular deformation. Tensile residual stresses which are generated due to welding in the weld region may lead to early failure of the structure when subjected to cyclic loading. The weld-induced residual distortion causes dimensional inaccu- racy and needs rework to achieve the desired shape. Use of mul- tiple welding passes without any optimized welding sequences typically leads to an increased degree of nonuniform heating and cooling, i.e., creating complex welding residual stress and angular deformation in the structure. In this present study, the effect of four different welding sequences on submerged arc welded fillet joint has been studied. A finite element-based numerical model has been developed to predict the thermal profile, welding resid- ual stress, and angular deformation. The developed model con- siders temperature-dependent material property and material de- position by using element death and birth technique. The results have been compared with experimental one. In the effect of welding sequence on residual stress, angular deformation has been studied. Thus, the developed model presents the effect of welding sequence on the weld induced residual stresses and distortions which provide one of the most optimal welding sequence for enhanced fabrication process. Keywords (IIW Thesaurus) Finite element analysis . Element death and birth . Plastic strain . Welding residual distortion . Stiffened panel . Fillet joint 1 Introduction Large structures are made by assembling different small compo- nents which joined together by several welding passes. Any large structure like ships and bridges contain huge number of stiffener joints. It has been observed that welding sequences have signif- icant effect on welding induced residual stresses and angular deformation. The ship hull girder consists of several stiffened panels where several welding passes are required for fabrication; here, welding pass plays a very crucial role on the weld-induced residual stress and angular deformation. As the means of welding is fusion, the welding heat source is sufficient to melt the elec- trode and the base metal to join the components together; thus, the local heating produces enormous thermal gradient and non- uniform cooling of the base metal produces thermal stresses followed by residual stress and deformation. The material near to the weld zone reaches to plastic state due to thermal strain which causes the development of shrinkage forces to lead to the angular distortion of the welded joint [1]. Angular distortion in a welded structure also results from the high thermal gradients followed by high expansion and contrac- tion of the weld metal and the neighboring base metal during the heating and cooling process of the welding. Due to higher tem- perature difference with the surrounding, the molten metal at the weld zone gets cooled and shrinks much faster than the surround- ing base metal. When several pass of welding is done after one pass, the adjacent base metal gets preheated. The controlled Recommended for publication by Commission X - Structural Performances of Welded Joints - Fracture Avoidance * Arpan Kumar Mondal m.arpan@iitg.ernet.in 1 Department of Mechanical Engineering, Indian Institute of Technology Guwahati, Guwahati, Assam 781039, India 2 Department of Mechanical Engineering, National Institute of Technical Teachers’ Training & Research Kolkata, Kolkata, West Bengal 700106, India Weld World DOI 10.1007/s40194-017-0468-3