Study On Welding Residual Stress And Distortions In Subway Structure

Based on the program of Mumbai subway, the research analyzes the influence of different welding procedure on residual stress of side beam, and how to choose the welding sequence to make sure the deformation of the side beam is the smallest.Considering the economic factors and maneuverability, T-joint plates are used to replace the side beam in order to research the influence of different welding procedure on residual stress. The welding temperature field of T-joint plates was measured by using an infrared thermal imager, and the thermal cycles were experienced during welding were achieved; the residual stress of T-joint plates were measured by blind-hole method. After the experiment, the finite element method was used to verify the results. The results showed that the method of TIG remelting could limitedly Lower the residual stress in seam center area, but the residual stress in remelting area were increased. However, by the overall heat treatment much residual stress brought by TIG remelting could be eliminated effectively. In addition, the experimental results also verified the accuracy of the finite element method.At last, the same finite element method was used to simulate the welding process on the side beam of the subway; and the data about welding deformation of side beam welded by different welding sequence was acquired, which provide the basis for practical work.