Effect of welding sequence to minimize fillet welding distortion in a ship’s small component fabrication using joint rigidity method

Abstract

This study was performed to investigate the effect of welding sequence on fillet welding distortion. It proposes a new model of joint rigidity method, which can determine the welding sequence for minimum welding distortion, through a reliability validation done via experiments and welding distortion analysis using the equivalent load method. A new joint rigidity method considers the gap between base plate and stiffener and the fillet welding sequence at left/right bead. Fillet welding sequence at left/right bead could be considered by setting welding beads at left/right as a separate solid element after welding sequence was drawn by new joint rigidity method. Analysis and experiment for welding distortion for the test specimen with different stiffener distances were conducted. It was confirmed that the experimental and analysis results were well-matched. The validity of welding sequence using joint rigidity method was followed after the comparison of the welding distortion for the small components for ship building. Note that the welding sequence by which welding distortion became maximum and minimum was drawn using joint rigidity method for the small assembly components. Welding distortion was also analyzed using equivalent load method. Analysis results revealed that the maximum welding distortion less than 10 mm was generated. Welding distortion less than around 5 mm occurred in welding sequence which minimized welding distortion compared with welding sequence, generating maximum welding distortion.