%A WU Zhiyuan, YAN Han, WU Linchao, MA Hui, QU Yegao, ZHANG Wenming %T Vibration characteristics of rotating cracked-blade-flexible-disk coupling system %0 Journal Article %D 2022 %J Acta Aeronautica et Astronautica Sinica %R 10.7527/S1000-6893.2021.25442 %P 625442-625442 %V 43 %N 9 %U {https://hkxb.buaa.edu.cn/CN/abstract/article_18671.shtml} %8 2022-09-15 %X Being exposed to severe environments with complex excitation for a long time, aero-engine blades can easily cause damage and cracks, which will change the modal characteristics of the blade-disk coupling system and deviate from the initial design state. Taking the rotating cracked-blade-flexible-disk coupling system as the research object, a dynamic model is established, in which the flexible disk and rotating blades are investigated based on Kirchhoff plate and Timoshenko beam theories; the blade crack is equivalent to the rotational stiffness based on the released strain energy and Castigliano's theorem. The proposed method is verified by modal test and finite element method. In addition, the effects of crack length, crack position, disk thickness and rotating speed on the inherent characteristics of the coupling system are investigated. The research results show that: the crack leads to the destruction of the initial orthogonal blade-disk coupling modal and the phenomenon of modal localization, and the corresponding frequencies decrease with the increase of the crack length; the closer the crack position is to the blade tip, the modes localization disappears, and two-order orthogonal modes are formed; with the increase of the disk thickness, the frequency veering phenomenon occurs, and the blade-bending mode is related to multi-order modes of the disk; with the increase of speed, the frequency veering phenomenon occurs, and the blade-bending mode is related to the rest blade-bending modes at the high rotational speed.