A hybrid variable-stiffness-and-damping control strategy for modal vibration suppression in rotor systems

Vibration threatens the safety and lifespan of aero-engines. Existing variable damping strategies are insufficient for multi-mode rotor systems, especially for vibration modes that are insensitive to damping. The active elastic support-dry friction damper (AESDFD) is considered a reliable active control mechanism, promising to address the safety and durability issues caused by vibration in aero-engines. To realize this potential, this study develops a refined multi-point ball-head contact model that accurately captures the voltage-force relationship of the AESDFD, achieving a modeling error below 5%. Based on this model, a hybrid control strategy is proposed, which synergistically combines the variable stiffness from the damper’s viscous state and the variable damping from its slipping state. This approach maintains wide-range adjustability of critical speeds while ensuring robust vibration suppression. Experimental results show that the stiffness control reduces vibration amplitude by 91.62% and acceleration by 81.46%, whereas the damping control achieves reductions of 18.75% and 16.61%, respectively. This work provides a comprehensive framework for active vibration control in aero-engines.