ESTIMATION OF WELD INDUCED RESIDUAL STRESSES OF THICK WELDED SECTIONS USING NUMERICAL WELDING SIMULATION

摘要

Welding processes are quite complex in nature as they involve the interaction of multiple physical phenomena. The thermal history developed during the process causes the material to undergo complex phase transformations. Non-uniform contraction and expansion of heat affected, softer, areas constrained by cooler, harder, areas of the material induce residual stresses and the weldment undergoes permanent deformation. When thick sections are welded, the formation of phases and the distribution of residual stresses are even more complex. These could lead to failure of the welded components during service. For the design of pressure vessel applications understanding the phase formation and residual stress distribution in thick weldments is critical. Numerical simulation was used to understand the influence of multiple variables on the residual stresses induced by a welding process The challenges involved in performing welding simulation of thick sections are described. Furthermore numerical and experimental results are compared and discussed.