Experimental research on dynamic behavior of a rotor-support system with squirrel-cage squeeze film dampers subjected to roll-pitch coupling motions

In flight states, the vibrations of on-board engine rotor-support systems are often intensified under external excitations, even exceeding the limits. To deal with this issue, a novel test bench combining spatial rotations with rotor dynamics was established, and a multi-disk rotor system supported by rolling bearings and squeeze film dampers (SFDs) was designed. Experiments were conducted on dynamic characteristics of rotor-SFD-support system under different non-inertial motions like rolling, pitching, and coupled motions. Dynamic signals like displacement, strain, velocity, and dynamic pressure were measured and processed by Vold-Kalman order tracking filter (VKF_OT). The results indicated that when the base performs rolling or pitching motion, the elastic squirrel-cages undergo periodic deformation due to the gravity; and the signals are all superimposed with a low-frequency component changing with base angular velocity. The additional inertial forces induced by pitching motions cause vibration displacements to deviate along the horizontal direction. The dynamic trajectories become more complicated due to the superposition of high-frequency vibrations and low-frequency variations of instantaneous static eccentricity. Multi-degree-of-freedom (MDOF) spatial motions and high-speed rotor rotations are achieved, and dynamic behavior of complicated rotor-SFD-support system under non-inertial motions are studied. The oil films should be formed in SFDs through assembly and oil supply, otherwise it will cause damping failure. In the design process, the limit value of elastic support stiffness should be given based on the maximum angular velocity. Such research results provide technical and data support for dynamic design and vibration control of engine rotor systems with high maneuverability. © 2026 Elsevier Ltd.