钛合金宽弦空心风扇叶片非均质结构加工均一化协同控制研究

针对钛合金宽弦空心风扇叶片的非均质结构（空间曲面空心夹层与实体混杂结构）特征，基于宽弦空心风扇叶片的全尺寸测量数据（叶片外形轮廓数据和空心结构内外形壁厚数据），结合计算机辅助设计方法，重构与叶片非均质空间曲面结构内形相协调的外形模型，并利用误差补偿技术和切削加工手段使空心结构壁厚均匀，建立基于壁厚精度均一化的误差补偿理论与方法；建立强弱相间曲面外形结构加工变形控制预报模型，形成控制策略，控制残余应力引起的零件加工变形。实现利用基于内形的壁厚精度均一化误差补偿方法重构外形模型，并通过有效控制切削加工变形精确获得重构外形轮廓的叶片机械加工协同控制策略，最终保证非均质曲面结构精度均一、避免或减少出现结构局部失衡，以达到提高宽弦空心风扇叶片高周疲劳寿命的目的。项目的研究成功可为钛合金宽弦空心叶片在先进航空发动机中获得应用奠定基础。

Titanium alloy wide-chord hollow fan blade has a heterogeneous structure of curved surface hollow interlayer and solid, which is difficult to machine. To resolve this problem, a method about reconstructing external shape model of heterogeneous surface structure coordinated with its internal shape by means of CAD method is put forward. To reconstruct this model, a full-size measurement method is adopted to achieve hollow fan blade size data, containing external contour data and wall thickness data between internal and external surface of hollow structure. By using error compensation technique and cutting method, the accuracy homogenization of wall thickness is achieved. Meanwhile, an error compensation theory and method are established; A model for forecasting residual stress existing in heterogeneous surface structure which has both high stiffness and low stiffness parts is established. Based on this model, a controlling strategy is formed, which can decrease machining deformation efficiently caused by residual stress. Thus, a cooperative controlling strategy for titanium hollow fan blade machining is obtained. With this strategy, homogeneous accuracy of heterogeneous surface is achieved, and surface local imbalance is avoided or reduced, which can improve high cycle fatigue life of wide-chord hollow fan blade efficiently and susessfully apply in the manufacturing of advanced aero-engine.