Influence of triangle reinforcement plate stiffeners on welding distortion mitigation of fillet welded structure for lightweight fabrication

Abstract

To ensure the dimensional accuracy of fillet welded structures of a cantilever beam, triangle reinforcement plate stiffeners (TRPs) are employed to prevent welding distortion. However, this increases the weight of a structure. In this study, an efficient finite element (FE) computation was used to solve the afore mentioned engineering problem. The inherent deformations of typical welded joints in a mock-up welded structure were estimated through thermal elastic plastic FE (TEP FE) analysis. Subsequently, welding distortion of the mock-up welded structure was computed via elastic FE analysis wherein the inherent deformation was applied as a mechanical load. Specifically, the inherent deformation of a bevel fillet welded joint was initially estimated, and its precision was verified. The computed Z-direction welding displacement of a flange plate in the mock-up welded structure was in good agreement with the measured values. Hence, it was evident that TRPs mitigated the welding deflection of the flange plate. A series of elastic FE computations showed that the Z-direction welding displacement of the flange plate in an actual welded structure does not increase. However, the total weight of the actual welded structure apparently decreases when the position and number of TRPs are optimized.