Research On The Deformations And Residual Stresses Of Complex Thin-walled Parts In Milling Machining

Thin-walled parts have a complex structure, high material removal rate and the characteristics of poor rigidity. After machining, the thin-walled parts usually be such as bending, twisting deformation. Machining accuracy is extremely difficulty to meet the design requirements. The big problem of the thin-walled parts manufacturing is deformation. Complex thin-walled parts with low rigid, which is widely used in aerospace engineering, is studied in this paper. We do the research on releasing of residual stress, force and impact of the cutting parameters, tool path, processing order and clamping schemes involved in the processing plan. Expand the following studies:First of all, the milling finite element model was established according to the metal milling mechanism. Using AdvantEdge finite element software found cutting simulation element model which use the elastic-plastic three-dimensional finite element technique and Johnson-Cook constitutive model to analysis the cutting force of different cutting parameters and the impact of residual stress. We do some experiments to prove the results of simulation experiments.Then, we establish the aerospace aluminum alloy initial residual stress and cutting residual stress leading to parts machining deformation finite element model to analyze the influence of initial stress for deformation of the thin-walled parts. We find a right way to remove margin and can reduce the deformation of the thin-walled parts. According to the different effects of different cutting depth on the deformation of the thin-walled parts, we arrange different cutting depth to improve the efficiency and quality of thin-walled parts.Again, we establish a finite element model to analyze machining sequence and tool path of thin-walled parts. We measure the Distribution of residual stress in the surface of workpiece, and input into finite element model, finding minimal deformation of tool path impact. We establish a different order of the finite element machining model, the residual stress on the part deformation, select the optimal cutting order.Finally, prediction model of the machining deformations was developed considering multi-factors coupling effects including original residual stresses, clamping load, milling mechanical load. And puts forward the process of the thin-walled parts to improve the precision machining of thin-walled parts.