COMBINED MULTI-FREQUENCY PARAMETRIC VIBRATION OF PLATE UNDER BASE EXCITATION AND CENTRIFUGAL FIELD

Rotating structures under base excitation are prevalent in engineering systems. This study investigates the frequency characteristics of parametric vibration for rotating plates induced by centrifugal fields and multi-frequency base excitations. A dynamic model of the plate under 6-DOF motion is introduced, revealing time-periodic stiffness characteristics dependent on excitation frequency with the Rayleigh-Ritz approach. The frequency components of the system response are predicted by a method of multiple scales, and key frequency components including combinations of parametric excitation frequencies, external excitation frequencies and natural frequencies are identified. Numerical solutions via the Newmark method quantitatively demonstrate how key parameters govern these frequency phenomena. Experimental validation is conducted on a uniformly rotating plate subjected to controlled base excitation, with measured responses confirming the coexistence of harmonic and combination frequencies predicted by theoretical and numerical analyses. The consistent agreement across methodologies underscores the model's reliability in the prediction of the frequency components within rotating systems, providing critical insights for engineering safety assessments.