Prediction of Welding Distortion and Panel Buckling of Car Carrier Decks using Database Generated by FEA

Straightening of welding deformation in shipbuilding is an expensive and time consuming process. Therefore, minimizing welding deformation is required in both design and construction stages. When welding thin plates such as those used in passenger car decks in Car Carriers, welding longitudinal shrinkage, caused by welding tendon force, causes compressive stress in the surrounding plate fields that sometimes causes these plate fields to buckle. Straightening of a buckled plate is difficult and buckling should be avoided whenever possible. For this purpose, a cross stiffened panel of a car deck of a Car Carrier is considered. A series of thermal elastic plastic finite element analyses is carried out to predict the welding tendon forces of Longitudinals and Transverses when utilizing continuous and intermittent welding with different welding process specifications. Bi-directional residual compressive stresses are evaluated and buckling is checked. Results indicate that when the geometry of the welded cross-section is similar, welding tendon force depends almost only on the average heat input per unit length of the weld line, no matter whether welding is continuous or intermittent. The effectiveness of parallel and zigzag intermittent welding in reducing welding residual stress and preventing buckling is quantified. A tendon force database may be created such that designers may easily check buckling and select welding specification