%A JIN Yulin, LIU Zhiwen, CHEN Yushu %T Fault simulation of blade-casing rubbing for dual-rotor system of aero-engines %0 Journal Article %D 2022 %J Acta Aeronautica et Astronautica Sinica %R 10.7527/S1000-6893.2021.25072 %P 425072-425072 %V 43 %N 12 %U {https://hkxb.buaa.edu.cn/CN/abstract/article_18531.shtml} %8 %X Blade-casing rubbing have very important effect on the performance, reliability and safety of the aero-engine. A dynamic model of the dual rotor-bearing system of the aero-engine is established based on the Finite Element Method (FEM) by taking into account blade-casing rubbing, misalignment and nonlinearities of the rolling element bearings. The Component Mode Synthesis (CMS) method is applied to reduce the high-degrees of freedom of the dynamic model, and the nonlinear vibration responses of the reduced order model are analyzed by the numerical method to reveal the features of blade-casing rubbing. The results of simulation and experiment show that the dual rotor-bearing system of the aero-engine is a multi-excitation nonlinear system, which presents complex frequency components for the vibration response, such as the rotation frequencies, multiple frequency components and combined frequencies of the high-pressure rotor and low-pressure rotor. For a wide blade-tip clearance, the blade-casing rubbing may be local rub-impact, where the fault feature frequency is manifested as the pass frequency of the blade and the corresponding doubling frequency, and there are a cluster of side bands on feature frequencies which are modulated by rotating frequencies of the dual rotor. For a small blade-tip clearance, the blade-casing rubbing may be full annular rub-impact, where a strong self-excited vibration is induced by dry friction. The results can provide references to fault diagnosis of blade-casing rubbing and blade-tip clearance design for the dual rotor system of aero-engine.