Numerical Simulation Of The Welding And Working Process In The Jack Et With Flexible Arc-plates Of Reduction Furnace And Its Amelioration

A jacket is a kind of heating or cooling equipment which is widely used in chemical, pharmaceutical and other industries. The welding area of a jacket is the failure part where cracks and leakage are often found. The welding residual stress in the weld area is one of the most important causes for the leakage. A numercial simulation by FEM on temperature field, welding residual thermal stress and plastic strain of a new type of jacket with flexibility of polysilicon reduction furnace has been conducted in this paper. By using the ANSYS APDL programming, the element birth and death technology, the direct thermo-structure coupling method, Gaussian heat source and the BKIN material constitutive model with various parameters at different temperature are all employed in the simulation including the transient heat transmission analysis and the steady stress analysis with the coupling effect of thermal deformation and field. As results, the distribution of residual stress in the weld area is obtained. The effective methods are provided for the weld strength evaluation of the similar type of flexible jackets.According to the design paper change the radius of curvature and Optimize the original flexible structure. It is obtained that the stress and strain in the welding field of the different radius of curvature model. Comparing the stress value of the different design radius of model, it is attained a more reasonable design radius.This thesis calculated the stress of the flexible structure on actual working condition. Analyze the displacement field, the temperature field and stress field of structure. Calculated flexible structure model of different radius on working condition and obtained the regular pattern of the displacement field of different design radius, discusses and analyses the regular pattern of stress in the welding field of different design radius. It is obtained that with the decrease of radius, the stress concentration in the weld area would decrease. Combined with the heat stresses in the weld areas, obtained a more reasonable radius.