Abstract
Experimental results are presented on chaotic oscillations of a clamped shallow arch. The arch has a large curvature and initial axial displacement by heat expansion. Due to the large curvature of the arch and its axial displacement, the lowest vibration mode of the arch is asymmetric and 2nd mode is symmetric. The arch is shaken laterally by an electromagnetic exciter. Chaotic responses are examined by the Poincare projections, Fourier spectrum and the maximum Lyapunov exponents. Contributions of vibration modes on the chaotic oscillations are examined by the principal component analysis. Chaotic responses due to internal resonance and dynamic snap-through are obserbed in specific regions of the exciting frequency. The chaotic oscillation generated from internal resonance including super-harmonic resonance of second and third modes has relatively large contribution of higher vibration modes. Chaotic oscillations including dynamic snap-through generated from principal resonance of the lowest vibration mode have relatively large contributions of the asymmetric modes.
