Analysis on vibration reduction of a rotating dovetailed blade with underplatform damper and installation preload

The vibration reduction characteristics of the flexible blade with a dovetail joint and underplatform damper are studied in this paper. Considering the influence of the platform mass on the inherent characteristics of the blade, this paper regards the underplatform as a particle with mass. Moreover, two types of friction models are introduced on the contact interfaces of the blade. Meanwhile, the normal pressure of the contact interfaces will change with the rotating speed of the blade. Also, the dynamical equation for the rotating blade is established based on the finite element method. The nonlinear friction force on the contact interface is brought into the dynamical equation, and the vibration response of the blade is solved. The effects of the rotating speed, the initial preload, and the contact angle of the underplatform on the vibration reduction characteristic of the blade are investigated.