| Aluminum alloy is widely used in aeronautics and astronautics.Thin-walled part has a feature of terrible stiffness,larger machining allowance,bad manufacturability during milling process that cause vibrations in machining,which not only decrease the precision of workpiece,but also make great influence on tool life.In order to improve the thin-walled part machining quantity,S-shaped thin-walled part made from 7075-T6 are regarded as research object.The flexible workpiece milling system dynamic model was built based on chronology non-deformation cutting depth model during machining of ball-end milling.Milling tremor 3-D stability model is made.Factors which make influence on thin-walled part machining stability is studied.The constraint of machining parameters is determined.Taking the distribution of milling system comprehensive stiffness with thinwalled vane as object,combining the comprehensive stiffness field model of 5-axis machining system and kinematic model of machining system to analyze the distribution of milling system comprehensive stiffness performance.Optimizing the low-stiffness part,making it clear the influence made from machining system comprehensive stiffness performance to milling process.Surface location error model of thin-walled part during milling process made based on harmonic balance method is taken as example to analyze the influence form spindle speed and the radical cutting depth to dynamic location error.Considering method of cutter orientation and cutting path and method of force ellipsoid.S-shaped thin-walled part milling parameter was optimized based on genetic algorithm with a object function of machining error and material removal rate,and a constraint of milling stability,surface location error,machining system stiffness field.Through the experimental verification.The optimizing method is proved to make a guidance to thin-walled part high-speed stable machining and machining parameter optimization. |
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