Abstract
Numerical results are presented on chaotic vibrations of a shallow clamped arch deformed by initial axial displacement. Especially, the effect of excitation amplitude on chaotic responses is examined. When the excitation amplitude is small, chaotic responses due to internal resonance are observed in specific regions of the exciting frequency around each stable equilibrium points. Chaotic vibration around one of the equilibrium points is generated from internal resonance including ultra-subharmonic resonance of the lowest mode and principal resonance of the second mode. Chaotic vibration around the other equilibrium points is generated from internal resonance including sub-harmonic resonance of the lowest and the second mode. When the excitation amplitude is large, chaotic response due to internal response around an equilibrium point irregularly transits to chaotic response around another equilibrium point with dynamic snap-through in long-term.
