Simulation of welding process and welding deformation and welding of steel structure in construction engineering ansys Stress finite element analysis
During welding, heating and cooling cycles always lead to a certain degree of deformation. Welding deformation has a great impact on dimensional stability and structural mechanical properties. Controlling welding deformation is a key task in welding processing. In the welding of steel structures, the welding process will cause uneven changes in the temperature field of components, resulting in complex residual stress distribution in components. Residual stress is a self balanced force system. When a component bears a load, such as tension, compression, etc., the stress caused by the load will be superimposed with the residual stress of the section, so that some parts of the component reach the yield strength in advance and plastic deformation will occur, which will seriously reduce the stiffness and stability of the component and the structural fatigue strength. When welding components, uneven temperature field with local high temperature will be generated on the weldment. The temperature at the welding center can reach 1600 ℃. The steel in the high temperature zone will expand and extend to a large extent, but it is constrained by adjacent steel, which will cause higher temperature stress in the weldment. During welding, it changes with time and temperature, and is called welding stress. The parts with high welding stress will even reach the yield strength of the steel and plastic deformation will occur, so there will be residual stress in the weldment after the steel is cooled, which is called welding residual stress. During the cooling process, the steel is stretched because it cannot shrink freely, so there is an internal stress field in the weldment that is roughly opposite to the heating direction of the weldment.
