In this paper, the self-programmed spring-beam-shell hybrid element combined with the Lagrange multiplier method is utilized to establish the finite element model of a fully flexible shaft-blisk-casing system with blade-tip rubbing fault. Particularly, an improved disk-blade interface coupling method is proposed. Besides, the Craig-Bampton method is adopted to establish a reduced system for efficiency promotion. Then the central difference method is applied to solve the rubbing dynamic responses of the reduced system under the effects of different rotating speeds, disk unbalances, and disk positions. Finally, some main conclusions are summarized as follows: (1) In the disk-blade coupling region, three sets of node pairs rather than single node pair are of good accuracy in simulating the dynamic coupling characteristics of the blisk model via the comparisons of the modal results obtained from the experiment and the three-dimensional model in ANSYS; (2) when rubbing with the oval casing, the odd-multiple harmonics in the spectrum of the blisk and the even-multiple harmonics in that of the casing are prominent. Besides, the rubbing region on the casing is usually near the minimum casing radius but changes into the upper- or lower-half zone of the casing under a larger speed.

本文采用自编程的弹簧-梁-壳混合单元，结合拉格朗日乘数法，建立了具有叶尖摩擦故障的全柔性轴-蜗壳系统的有限元模型。特别地，提出了一种改进的磁盘-刀片接口耦合方法。此外，采用克雷格-邦普顿方法建立了简化的效率提升系统。然后采用中心差分法求解在不同转速，盘不平衡度和盘位置的影响下，简化系统的摩擦动力响应。最后，主要结论归纳如下：（1）在圆盘叶片耦合区域，通过比较实验获得的模态结果和ANSYS中的三维模型，三组节点对（而不是单节点对）在模拟叶栅模型的动态耦合特性方面具有较高的精度。（2）当与椭圆形外壳摩擦时，在叶状体频谱中的奇数次谐波和在外壳频谱中的偶数次谐波是突出的。此外，套管上的摩擦区域通常接近最小套管半径，但在较大速度下变为套管的上半部或下半部。