Study On Machining Distortion Of 7055 Wing Panel

Modern large-scale wing panel have adopted integrated design and manufacturing to meet the demands of high strength, stiffness and resistance to fatigue, etc. However, the machining distortion brings bad impacts on the precision and processing safety. In this paper, numerical simulation and experiments were combined, from the aspects of bulk stress, cutting residual stress and vacuum adsorption with clamping, to predict and control the distortion of 7055 aluminum alloy wing panel. The major research works are listed as follows:(1) The bulk stresses of 25 mm 7055-T7751 pre-stretched aluminum alloy plate were measured using slitting method. The machining distortion caused by bulk stresses was analyzed from the aspects of geometry error and distortion. Also, the distortion was studied when the wing panel parts under different blanket thickness position.(2) The distribution of cutting residual stresses has been summarized to study the distortion. Compared with bulk stresses, the distortion caused by cutting residual stresses could be neglected.(3) The relation between minimum vacuum absorption and thickness of wing panel, the maximum rebound quantity when the vacuum leaks, were studied to determine the maximum secure distortion. 2 different layouts and 3 typical clamping sequences were researched to optimize the clamping process.(4) The process has been optimized from the aspects of the allowance allocation and processing sequence, and verified by numerical simulation and experiments. Compared to the original process, the final and middle distortion get huge decrease after the optimization process was applied.