Prediction and Welding sequence of Minimum Welding Deformation in Large Steel Block Welding

In order to minimize the effect of weld deformation on the preceding equipment during Pre-erection joint welding, the optimal welding sequence by unit load method was derived. And the weld deformation was predicted by the equivalent load method considering the constraint according to the derived welding sequence. For this purpose, the restraint coefficient was derived by conducting experiments and elastic FEM analysis on various welded specimens in order to derive the restraint of butt welds. In addition, the welding sequence that can minimize the welding deformation was derived by calculating the constraint by the unit load method in steel block structure. According to the derived welding procedure, the welding deformation near the preceding equipment during the pre-erection joint welding was predicted within 4 mm by using the equivalent load method considering the constraint. Specifically, the deformation in the lower part with the block supports occurred about 2 mm, and the deformation of 3~4 mm occurred at the upper part of block. Key words: Angular deformation, Equivalent load, Constraint coefficients, Elastic FEM