Study On Numerical Simulation Of Welding Deformation And Residual Stress Of Aluminum Alloy Based On ABAQUS

Welding as an advanced manufacturing technology was considered to be significant in the manufacturing process of complex structure,which occupied a unique position in the field of material processing.Due to the highly localized and instantaneity of welding heat process,it would inevitably produce welding stress and deformation,and seriously influence the quality of the welding structure and components.Therefore,how to accurately infer the mechanical behavior of welding structure,residual stress and welding deformation had always been a crucial and urgent research topic in welding mechanics.In recent years,with the rapid development of welding forecasting theory and the increasing maturity of computer technology,the welding numerical simulation which was used as an effective method to predict welding deformation had been widely researched and popularized.For the welding numerical simulation technology,the thermo-elastic-plastic finite element method was one of the most commonly welding numerical simulation technologies.It adequately took into account the influence of material physical,mechanical properties and the welding process parameters on welding thermal process,particularly tracked the whole evolution in the process of welding stress and strain,detailedly recorded the change trend of welding stress and deformation.Theoretically,it could deal with the problems of welding stress and deformation for any complicated components.At the same time,welding was a complex physicochemical process which included calorifics,mechanics and metallography.Therefore,the numerical simulation of welding process not only required to establish scientific and appropriate material model,mechanical model,heat source model,but also needed to solve the problem of the highly complicated nonlinear convergence.Currently,the low calculation efficiency and the low precision of the numerical simulation limited the widely application of numerical simulation technology,especially for the numerical simulation of welding deformation and residual stress.The research indicated that the calculation efficiency and precision of simulation was the key for the welding numerical simulation analysis.In addition,high efficiency,high precision of simulation had become a core subject in the field of welding.How to choose the most suitable solution according to different research backgrounds and demands,use short computing time as far as possible to get more accurate results was a complicated and crucial problem in the process of welding numerical simulation.The study of investigation proved that the application of the thermo-elastic-plastic indirect coupling method was most widely.But this method only took into account the influence of temperature field on welding stress field,ignored the reverse effect of stress field on temperature field which affected the calculation precision of the numerical simulation.Conversely,the thermo-elastic-plastic direct coupling method fully considered the two-way coupling effect,it truly reflected the essence of the welding processes.But so far,the study of thermo-elastic-plastic direct coupling method was less,and mainly concentrated on carbon steel materials.The related research about the welding simulation of aluminum alloy sheet which was easier to generate welding distortion were rarely.consequently,on the basis of the above study,the thermo-elastic-plastic finite element method was developed to simulate the welding process in consideration of geometrical nonlinearity,material nonlinearity based on the platform of commercial software ABAQUS.In the numerical simulation,5052 aluminum alloy thin plate was taken as research object.This paper designed different 3-D models to study the influence of different linear elements on the numerical simulation of residual stress and welding deformation.The residual stress and welding deformation of each model were derived from numerical simulation.Finally,the influence was drawn after comparing the calculating accuracy and calculating time of the welding numerical simulation in different linear elements.On the foundation of the study,a fully-coupled thermal-mechanical 3-D model was used to systematically analyze the thermo-mechanical coupling effect.Besides,by using the direct coupling method to predict the welding temperature field,welding stress field and distortion,then compare the simulation results with indirect coupling method.Through the above numerical simulations,some feasibility research were explored.Meanwhile,this study provided a valid reference for further research on the high precision prediction method.