钛合金宽弦空心风扇叶片进排气边加工变形预测

Machining Deformation Prediction of Titanium Alloy Wide Chord Hollow Fan Blade

针对残余应力和铣削载荷引起的钛合金宽弦空心风扇叶片铣削加工变形问题,提出了一种空心风扇叶片加工变形预测方法。通过正交试验得出铣削力经验公式,采用两种不同的走刀方式,结合"生死单元"技术实现叶片进排气边加工仿真;运用BP神经网络算法建立钛合金宽弦空心风扇叶片加工变形预报模型。通过分析不同走刀方式的加工变形量得出:环切铣削方式对于加工变形的影响大于行切铣削方式。变形预报结果与实际测量值相对误差在10%以内,变形预报相比有限元计算周期短,预测效率高。

Finite element simulation combined with BP neural network is applied to predict the machining deformation of titanium alloy hollow fan blade,which is caused by residual stress and milling load.The empirical formula of cutting force was obtained by orthogonal experiment of cutting force.The simulation of milling leading and tailing edge was performed by applying the model change technology.Combined with the BP neural network model for milling deformation forecast,wide chord hollow fan blade milling deformation forecast was realized both in stroke milling and ring-cut milling.The simulation results show that ring-cut milling deformation is much larger than that of the stroke milling.The relative error between the deformation results which were predicted by BP neural network and the measured value is less than 10%.The efficiency of deformation prediction is higher than simulation prediction,and the accuracy of deformation prediction is as good as simulation prediction.