Dynamic Characteristics of Rotor System with a Slant Crack Based on Fractional Damping  

作　　者：Zhinong Li Yunlong Li Dong Wang Zhike Peng Haifeng Wang 

机构地区：[1]Key Laboratory of Nondestructive Testing,Ministry of Education,Nanchang Hangkong University,Nanchang 330063,China [2]Laboratory of Science and Technology on Integrated Logistics Support,National University of Defense Technology,Changsha 410073,China [3]State Key Laboratory of Mechanical Systems and Vibration,Shanghai Jiaotong University,Shanghai 200240,China

出　　处：《Chinese Journal of Mechanical Engineering》2021年第2期79-96,共18页中国机械工程学报（英文版）

基　　金：supported by National Natural Science Foundation of China(Grant Nos.51675258,51261024,51265039);State Key Laboratory of Mechani-cal System and Vibration(Grant No.MSV201914);Laboratory of Science and Technology on Integrated Logistics Support,National University of Defense Technology(Grant No.6142003190210).

摘　　要：The traditional modeling method of rotor system with a slant crack considers only integer-order calculus.However,the model of rotor system based on integer-order calculus can merely describe local characteristics,not historical dependent process.The occur of fractional order calculus just makes up for the deficiency in integer-order calculus.Therefore,a new dynamic model with a slant crack based on fractional damping is proposed.Here,the stiffness of rotor system with a slant crack is solved by zero stress intensity factor method.The proposed model is simulated by Runge-Kutta method and continued fraction Euler method.The influence of the fractional order,rotating speed,and crack depth on the dynamic characteristics of rotor system is discussed.The simulation results show that the amplitude of torsional excitation frequency increases significantly with the increase of the fractional order.With the increase of the rotating speed,the amplitude of first harmonic component becomes gradually larger,the amplitude of the second harmonic becomes smaller,while the amplitude of the other frequency components is almost invariant.The shaft orbit changes gradually from an internal 8-type shape to an ellipse-type shape without overlapping.With the increase of the slant crack depth,the amplitude of the transverse response frequency in the rotor system with a slant crack increases,and the amplitude in the second harmonic component also increases significantly.In addition,the torsional excitation frequency and other coupling frequency components also occur.The proposed model is further verified by the experiment.The valuable conclusion can provide an important guideline for the fault diagnosis of rotor system with a slant crack.

关 键 词：Fractional calculus Slant crack Rotor system Dynamic characteristics 

分 类 号：TH113[机械工程—机械设计及理论]