Abstract
This paper presents experimental results on chaotic vibrations of a thin annular plate. The plate is clamped on outer edge and free on inner edge. When the plate is subjected to lateral periodic excitation, chaotic responses are observed within the large amplitude response. Predominant resonance is generated due to internal resonance. Principal component analysis is adapted to find the mode contributions to the chaos. The time responses of the plate are measured at four positions simultaneously. As a result, principal component analysis for the short time period of the chaotic response shows the existence of traveling waves in the chaotic response of the annular plate.