NUMERICAL ANALYSIS ON WELDING RESIDUAL STRESS IN Q690 HIGH-STRENGTH STEEL PIPE

The distribution of longitudinal residual stresses in Q690 welded high-strength steel pipe is analyzed. The ‘life and death element’ and thermal-structural coupling analysis function of ANSYS are used to simulate the welding process. With the variables of pipe diameter and wall thickness, three groups of twelve finite element models are designed. The longitudinal residual stress distribution of each model is derived from numerical analysis, and the regularity of the residual stress distribution is obtained by comparison. A simplified distributional pattern for longitudinal residual stress in Q690 high-strength welding steel pipe is proposed. The results show that it is similar to the distributional pattern which Wagner proposed, but the ratio of residual compressive peak stress to the yield stress for Q690 high-strength welding steel pipe is 0.2, which is less than that of normal-strength welding steel pipe.