Welding Deformation Analysis And Numerical Simulation Of Large Aeronautical Structural Parts

During the welding process,the uneven temperature field is caused by the uneven heating of the material.The large thermal gradient and the effect of welding residual stress make the structure produce welding deformation.Welding residual stress and deformation have a serious impact on the strength,stiffness and service performance of the structure.If the residual stress and deformation after welding can be predicted in advance,the welding deformation can be reduced or controlled by subsequent process methods.Aluminum alloy welded components are generally large in size and complex in structure.In the welding process,they are affected by welding sequence,process parameters,welding fixture and so on.In practice,there are many uncontrollable factors.Generally speaking,it is difficult to achieve deformation prediction through test methods.How to control and reduce welding residual stress and deformation has become an urgent problem in engineering.The development of finite element technology has brought convenience to solve the problem of predicting welding deformation of large-scale aluminium alloy structural parts.In this paper,a large aeronautical structure is taken as the research object,and the behavior and law of welding residual stress and deformation under laser welding are analyzed.Based on the elastic-plastic finite element method,a special non-linear finite element simulation software simufact.welding is used to simulate the numerical results.By analyzing the welding temperature field and stress-strain field of the structure,the thermal cycle curve and the influence of residual stress on the structural deformation are obtained.By optimizing the sequence of the long weld,the method of optimizing the welding sequence of the long weld is obtained,and then the welding sequence of the whole structure is optimized.This paper provides a reference for welding process optimization in practical engineering.The main contents of this paper are as follows:(1)The temperature field and stress-strain field of the structure are simulated and analyzed,and the distribution of temperature,stress and deformation of the structure is obtained.(2)The structural deformation distribution under different constraints is studied,the influence of constraints on the structure is analyzed,and the constraints of the structure are optimized.(3)To optimize the welding sequence of longitudinal long seam,which has a great influence on the structural deformation,and obtain the optimization rule of the welding sequence of long seam.Then,the welding sequence of the whole structure is optimized by using the optimal scheme of single seam.