Vibration reduction characteristics analysis and experimental study of staggered-type double elastic ring squeeze film damper under complex operating conditions

To address the challenge of suppressing engine rotor system vibrations under complex conditions such as impact loads and maneuvering overloads in carrier-based aircraft, a staggered-type double elastic ring squeeze film damper (SDERSFD) is proposed in this study. The vibration reduction characteristics of the damper are systematically investigated through theoretically analyzed and experimentally studied. Leveraging the circumferential staggered structure of the elastic rings, a staggered-type double elastic ring (SDER) finite element model and a staggered bidirectional pressure transfer iteration method are established. This method achieves dynamic connection of the oil film between the two elastic rings and maintains pressure equilibrium with a residual differential of less than 0.1‰. A nonlinear finite element model of the rotor system with the SDERSFD was developed to investigate its vibration reduction under complex operating conditions, including impact loads and turning maneuvers. To validate the vibration attenuation performance of the SDERSFD, a rotor experimental system with SDERSFD was designed and built. Experimental results demonstrate exceptional alignment between simulation and experimental testing, with critical speed deviations remaining below 2% and modal errors under 6.9%, thereby validating the accuracy of the calculation method. The SDERSFD exhibits effective vibration suppression in rotor systems, achieving maximum vibration reduction ratios of 74.7% under fixed base condition. Notably, the damper demonstrates 51.2% vibration reduction under pre-first-order critical speed impact condition and 65.6% reduction under pre-second-order critical speed overload condition. This study verifies that the SDERSFD enables effective vibration suppression and enhances rotor system stability under complex operating conditions.