Analysis Of Stress And Deformation Of The Welded AV Axial Flow Compressor Shell’s Key Welded Seam

With the development of the fan industry in our country,a lot of problems were exposed in the manufacture of large-scale shells by foundry, welded structure production received increasing recognition. Furthermore, based on the welded deformation and residual stress of AV 112 axial flow, adopting numerical simulation and test approach, deeply discusses multi-pass welding residual stress and welded deformation of butt welded joint and T welded joint of the thick plate, in order to provide guidance for decreasing the residual stress and welded deformation in the manufature of the welded large-scale blast fan shells.Firstly, in the way of numerical simulation, the residual stress and welding deformation of the thick plate were analyzed in this paper and the result show that, in the report of the stress field, the longitudinal stress takes on transition from center to edge, tensile stress to compression stress in the vertical direction of the welded seam. Compared with the longitudinal residual stress, the horizontal residual stess has the same tendency except that the value of the horizontal residual stress is smaller than that of the longitudinal direction and it vibrates fiercely in welded seam part. However, in the report of the welding deformation, both butt welded joint and T welded joint take on angular deformation,but the deforming degree of butt welded join(maximum deformation can reach 30mm) is more serious than that of T welded joint(maximum deformation is only 8mm). As a result, in order to verify the reliability of the simulation result, the mathar method was adopted to test the residual stress of the weldment surface, and the anastomose shows it could provide a reference for project application.Secondly, the existence of welding residual stress and welding deformations has great effects on the bearing capacity of structure. In order to make sure the security and reliability of the welded structure,the paper studies the elimination of the welding residual stress with heat processing,and it works effectively, providing an approach to eliminate the residual stress of the large-scale structure. Welding residual deformations is the key factor affecting the structure design integration、manufacturing technique rationality and structure applied reliability. For the purpose of preventing the adverse effection of the welding deformation on the manufacture,assembly and so on,an anti-deforming method is suggested to do the deal.Finally, the FEA and the actual testing results suggest that thermal elastic-plasticity method in practical project can be used for stress and temperature field analysis and inherent strain method can be used for deformation analysis. The reason is that the time-varying temperature, stress and strain distributions in welding process can be obtained by thermal elastic-plasticity method, which is useful for deeper understand of the welding process and acting effective control on it. That is to say, for welding deformation calculation, the inherent strain method can get higher accuracy besides other merits like once-needed elastic analysis and simple calculate process.