Key Laboratory of Nondestructive Testing;
Ministry of Education;
Nanchang Hangkong University;
Nanchang 330063;
China;
Laboratory of Science and Technology on Integrated Logistics Support;
National University of Defense Technology;
Changsha 410073;
China;
State Key Laboratory of Mechanical Systems and Vibration;
Shanghai Jiaotong University;
Shanghai 200240;
China.;
Fractional calculus; Slant crack; Rotor system; Dynamic characteristics;