Nonlinear Dynamics Analysis of Rod Fastened Rotor-Combined Support System

Abstract Rod fastened rotor is widely used in gas turbine and aero engine. Normally, rod fastened rotor is supported by sliding bearings, but in engineering, improper bearing clearance would lead to severe vibration of the system. Combined support, i.e., squirrel cage-squeeze film damper, could decrease the stiffness and increase the damping of the system. It is usually used to reduce the vibration of integral rotor. In this paper, the dynamic behaviour of rod fastened rotor-combined support system is explored. Based on the Lagrange equation, the equation of motion of rod fastened rotor-squirrel cage-squeeze film damper system is derived. The bistable behaviour and non-synchronous response are disclosed. Besides, a rod fastened rotor-squirrel cage-squeeze film damper bench is built, the bistable behaviour and non-synchronous response are proven experimentally, and the effect of the pressure of the oil film on the nonlinear dynamic behaviour is experimentally explored.