Nonlinear Forced Oscillations of a Rotating Disk : Primary Resonance Produced by a Force Synchronous with Disk Rotation

Nonlinear oscillation of a rotating disk excited by a force synchronous with disk rotation is considered. For theoretical analysis, modal equations are derived froin the governing partial differential equations. Then, based on these modal equations, the characteristics of the oscillation are investigated. Numerical calculation is conducted for a typical case in which the rotating speed approachs the primary resonance point of the backward traveling wave mode. It is shown that near this point the forward traveling wave mode oscillation occurs in addition to the backward traveling wave mode oscillation. Experimental analysis is a]so conducted, which confirms the validity of the theoretical analysis.