This paper is to present theoretical and experimental
vibration analysis of fluid dynamic bearing (FDB) spindles with
rotating-shaft design. In the theoretical analysis, a mathematical
model is developed to predict half-speed whirls, rocking modes,
frequency response functions, and shock responses. In the experimental
studies, FDB spindles carrying multiple disks are tested at
various spin speed. Frequency response functions (FRF) are obtained
to verify the mathematical model. The theoretical results
agree reasonably well with experimental results in both natural frequencies
and resonance amplitudes.