抄録
Experimental results are presented on chaotic vibrations of a circular plate with initial deformation. The plate is excited by lateral periodic excitation In typical frequency range, non-periodic response is observed. The response shows the irregular amplitude modulation. The response is examined by the Fourier spectra and the maximum Lyapunov exponent. The response is generated from internal resonance condition of one to four and the response is determined as the chaos. Multiple time responses of the plate are measured simultaneously. The principal components are calculated by the Karhunen-Loeve transformation. The three lower modes of vibration are generated in the chaos. The lowest mode of vibration contributes to the chaos dominantly. While, the second mode with one nodal diameter and the third mode with two nodal diameters contribute with small amount. However, the principal component with short time interval show that the third mode is generated in the large amplitude of response, while, the second mode prevail in the small amplitude of response.