BENCHMARK STUDY OF WELDING DEFORMATIONS IN STIFFENED PLATE

The fabrication of ship hulls involves welding operations, one typical operation is fillet welding of stiffeners to plates (panels) a so-called T-joint. The residual stresses from the welding process will influence the fatigue life of the structure, and residual deformations will increase the risk for buckling of the panel and give poor fabrication tolerances which may complicate the assembly of a built-up structure. Though this weld geometry has been frequently studied in the literature both experimentally and numerically, the focus has been on the residual stress field and if residual deformations are studied, the angular distortion and the typical V-shape seen in the welded plate (panel) are reported. This benchmark focusses on the residual shape after two-pass fillet welding of a stiffener to a plate (T-joint and the influence of the constraints used during welding. The information of the full welding residual deformations may be useful for the fabrication of larger complex welded structures. The benchmark study clearly shows that careful consideration is needed when defining a reference plane for comparison of resulting deformations from FE-simulations and from experiments as well as good documentation of the actual boundary conditions and steps carried after the completion of the welding and before measuring residual deformations. The FE-simulations have shown that it is difficult to obtain the full antisymmetric, twisted shape of the plate as measured in the experiments, although a trend similar to the experiments can be seen as the plate tends to move upwards at the end of each weld pass, i.e a slight influence of the weld pass direction.