Abstract
Experimental and anlaytical results are presented on modal interaction in chaotic vibrations of a shallow clamped arch deformed by initial axial displacement. Chaotic responses due to internal responce and dynamic snap-through are observed in specific regions of the exciting frequency. The responses are examined by the Fourier spectra, Poincare projections and the maximum Lyapunov exponents comparing the analytical and experimental results. Contribution of each vibration mode to the chaotic vibration is then analyzed by the Karhumen-Loeve transformation. The chaotic vibration generated from internal resonance including super-harmonic resonance of second and third modes has relatively large contribution of higher vibration modes. Chaotic vibrations including dynamic snap-through generated from sub-harmonic resonance of the lowest vibration mode have relatively large contributions of asymmetric mode.
