Analysis of stress intensity for dimple jacket

Due to the complexity of loading case in dimple jacket weld, the problem of leakage is always happened in weld, which is induced by cracks in weld.Welding residual stress is one of the main affected factors.By the finite element analysis code ABAQUS and the function of coupling process between heat and stress, the methods of plug welding and fillet welding were simulated for 304 stainless steel dimple jacket and the distribution of welding residual stress was obtained.The results indicated that the residual stress of plug welding was higher than the residual stress of fillet welding in weld.The much higher residual stress was produced by plug welding in the hole of dimple jacket, and the residual stress of first dimple jacket hole was affected greatly after the second hole had been welded.But the affection was little when the method of fillet welding was applied.Intensity calculation for plug welding and fillet welding was carried out, and the results shown that loading bearing capacity of fillet welding is better.The research results provided theory base for the analysis design and controlling welding cracks of dimple jacket.