Phase difference and stability of a shaft mounted a dry friction damper: Effects of viscous internal damping and gyroscopic moment

This study investigates the stability and phase difference of a shaft mounted a dry friction damper with effects of viscous internal damping and gyroscopic moment. The equations of the system with the vibration reduction effect of the dry friction damper on the shaft are derived in the form of the rectangular coordinate and polar coordinate in the vicinity of critical speed. The phase difference characteristics in the rub-impact process and its physical mechanism are analyzed by mathematical derivation. The characteristic equation is studied to investigate the stability of the periodic solution. Effects of different parameters of the system, especially viscous internal damping of the composite shaft and gyroscopic moment on the phase difference and stability regions are presented in detail by analytical and numerical simulation based on a helicopter tailrotor driveline. The experimental investigation is conducted in a test rig to validate theoretical formulas and simulation analysis. The analysis results show that rub impact delays the change of phase difference, viscous internal damping improves the stability of synchronous full annual rub solution, and gyroscopic moment affects the increase of the phase difference.

Automated summary

This study investigates the stability and phase difference of a shaft with a dry friction damper, incorporating effects of viscous internal damping and gyroscopic moment. Analytical and numerical simulations based on a helicopter tailrotor driveline are utilized to present the effects of various system parameters on phase difference and stability, with experimental validation conducted to confirm the theoretical formulas and simulation analysis. Results show that rub impact delays phase difference changes, viscous internal damping enhances stability, and gyroscopic moment influences the increase in phase difference.