An approach to predict the distortion of thin-walled parts affected by residual stress during the milling process

Among all the main influential factors on the distortion of thin-walled parts, residual stress plays a key role before or after the machining process. It is worth to control and propose an approach to predict the precision of workpiece after the processing has been completed. In this study, through comprehensive multi-factor optimization analysis and investigation, a thin-walled workpiece with aerospace frame is taken as the research object, followed by the proposition of a method of predicting the processing accuracy of the thin-walled part during the milling affected by the residual stress. Using the proposed approach and considering of the residual stress as the optimization goal, the optimized milling path should be arranged from the inside to the outside in the case of a single characteristic. By contrast, for the machining with different characteristics, the best processing sequence should be assigned reversely, from the outside to the inside. After using the prediction method and verification with a target thin-walled part, this study concludes that the smaller magnitude of surface initial and machined residual stress will reduce distortion of the thin-walled part. In this way, the processing accuracy and stability of thin-walled parts can be both improved and raised to a higher level.