Machining Sequence Optimization Method for Low-Stress Distortion of Large Planar Features in Structural Components

With the accelerated development and production of large equipment, structural components increasingly incorporate large planar features. These components exhibit poor rigidity, and machining-induced disruption of the original residual stress field within the blank leads to force imbalances, resulting in severe part distortion. Therefore, studying the evolution of residual stresses during machining is crucial for optimizing machining processes, controlling workpiece distortion, and improving part qualification rates. This paper first analyzes the mechanism of residual stress-induced distortion during machining. Subsequently, three machining sequences are experimentally designed for a typical aluminum alloy based on the initial surface residual stress field. The distortion magnitudes under different machining sequences are analyzed, leading to the conclusion that prioritizing the machining of regions with lower residual stress values reduces distortion. Finally, the applicability of this conclusion is validated through residual stress testing on TC4 titanium alloy, another typical structural material, confirming the accuracy of the proposed method. The study demonstrates that machining regions with smaller absolute stress values first, followed by other regions, effectively mitigates distortion in large planar features.