Reliability Analysis Of Welding Process Based On Welding Defects

Welding structure has been widely used in marine engineering,chemical,energy,aerospace,transportation,machinery industry,construction and other important industrial sectors.As the temperature changes violently in the welding process,the intense and uneven distribution of heat will result in defects in the welding structure,which affects the properties and reliability of the structure directly.For the reliability problems exposed in the welding process,it has great significance to analysis the reliability of welding process.The paper researches on the welding defects of residual stress,taking the residual stress as the characteristic parameters of the defect and gaining the major factors to establish the reliability approximate model.In the modeling methods of the approximate model,the response surface method is selected to establish the approximate model of process reliability.Then according to the uniform design method,the parameter combination of the simulation experiment is selected in order to reduce the number of tests.According to the combination of the simulation experiments,the welding process is simulated by the finite element software ANSYS.The finite element model of plate butt welding is established,and in order to improve the accuracy of the simulation analysis,the paper considers the properties of the material with temperature changes and adopts the reasonable meshing strategy.Then the double ellipsoid heat source model is loaded to obtain the results of the welding temperature field.The stress and strain field of welding is solved by indirect coupling method on the basis of the temperature field analysis,and eventually the distribution of the residual stress is obtained.The residual stress of different parameters is obtained by simulation,and then the reliability model of the welding residual stress is established based on the response surface method.The reliability model of the residual stress is analyzed by different reliability analysis methods.And the influence of the distribution parameters of the process factors on the reliability and its trend is obtained eventually.This paper researches on the reliability problems of the welding process.It has certain application value for the optimization of the welding process and the reliability improvement of the welding structure.