Control Butt Joint Angle Deformation Numerical Analysis Of The Binding Welding Problems

Welded structure is used widely in daily engineering. Welding residual stress and deformation will affect the carrying capacity of the structure directly. It is very important to forecast the welding stress and control the welding residual deformation exactly to ensure the safe reliability of the structure. Because the thermal elasto-plastic problem in welding is very complicated, it is too difficult to be dissolved by theoretic method. The method of test is widely used to ascertain welding residual stress previously. This method is too inconvenient and is restricted by the conditions, and the results have much error. The development of computer and software supplies condition to numerical simulation.The method of rigid fixing and backward deformation to control the welding residual angular distortion are numerical calculated by FEM (Finite Element Method) in this paper. This method can not only overcome the disadvantage of the testing but also verify the known conclusion. The main works of this paper are as follows:1. The process of pass filling dynamical multi-layer welding is realized by the method of loading-on welding heat source and using "Element Birth and Death" in ANSYS. The analysis of multi-layer butt-welding is accomplished by numeric method. This paper analyzes the temperature fields and residual angular distortion in the different time and how transverse residual stresses distributing. It is shown that the simulation results are in good accordance with the facts presence.2. This paper brings forward a model to simulate the rigid fixing method (restraint welding). The model is like this: vertical restraints are loaded at the locality where the restraint force will be loaded, when the weld is finished, the vertical restraints are unloaded.3. Restraint length, which can effectively control the residual angular distortion, is settled by the elasto-plastic theory of beam and the optimum theory. After the numeric analysis of the restraint welding, we know how transverse residual stresses of restraint welding distribute, and what's more we can find that restraint welding ameliorates the...