Theoretical and Experimental Study on the Transient Time-Frequency Characteristics of the Bending-Torsional Coupling Motions of a Rub-Impact Dual-Rotor System

This paper focuses on the fault characteristics of bending and torsional motions a rub-impact dual-rotor system caused by aircraft flight maneuvers. The equations bending-torsional coupling motion are established considering low-pressure rotor transient barrel roll an aircraft. 4th Runge-Kutta method with varied steps is used to obtain responses. Then, influences parameters, including stiffness, friction coefficient, rotating speed, investigated in detail. At last, rubbing experiment carried out, verifying validity simulation results. results show that stiffness affects vibration significantly sensitive coefficient. Correspondingly, responses apparent fractional frequencies within whole region stiffness. can only display at certain As for also more effective than detection low- high-speed regions. will contribute comprehensive basis detection.