The Effect Of Welding Residual Stress Of Cross Weld On The Behaviors Of Tubular Joints

The steel tubular structure, which is brief construction, beautiful appearance, is the first choice for large-span space structures, such as gymnasium, airport terminal, subway stations, and large industrial buildings. The joints with cross welds occur in these steel tubular structures inevitably. Near by the cross-weld, there will be three dimensional stresses which are in the same direction, which causes brittle fracture. It affects the ultimate capacity of the joint and reduces the structure's safety properties. The effect of residual stress is often ignored in past studies on ultimate capacity of the joint, and there are almost no studies on the joint with cross-welds. Therefore, it is necessary to study the effect of welding residual stress of cross weld on the behaviors of tubular joints.In this paper, the tubular joints with cross weld will be chosen, using ANSYS to simulate the process of welding. By using the technology of element birth and death and the language of APDL in ANSYS, we can simulate the process of gradually filled weld. We can use different welding speed and the start point of welding to simulate the different distributions and peaks of residual stress. The main pursers is study about the effect of welding residual stress in different distribution and peaks on the behaviors of tubular joints, also we can compare the capacity with the joint with holes in the cross weld.In order to study the effect of welding residual stress of cross weld on the behaviors of tubular joints, we choose 12 models (T1~T6, there are no holes in the cross weld, T7~T12, there are holes in the cross weld). In the paper, the main research work and the basic conclusion are as follows:1. The three-dimensional model of tubular joint with cross weld is created,the welding residual stress is solved by using the indirect coupled method.2. Using different welding speed and the start point of welding to simulate the different peaks and distributions of residual stress for study the effect of welding residual stress of cross weld on the behaviors of tubular joints.3. Creating the three-dimensional model of tubular joint with hole in cross weld, through numerical simulation to solve the distribution and peak of weld residual stress and the ultimate capacity, also comparing it with the node which has no holes in the cross weld. 4. It is effectively to reduce the peak of weld residual stress by making holes in the cross weld, but which is not obvious to improve the ultimate capacity of the tubular joints.