A flexible thin steel beam was mounted vertically to a
electromechanical shaker which provided a transverse
sinusoidal excitation. The beam tip was placed near two rare
earth magnets so as to provide nonlinear buckling forces. The
beam was treated with a viscoelastic strip adhered to one side
to provide a little damping. The addition of the damping
treatment helps to form a more distinguishable fractal
structure in phase space embeddings. A laser vibrometer was
used to record the beam tip velocity and the analog signal
streamed to a National Instruments data acquisition board. The
data was sampled at 1000 Hz. The gain of excitation was adjusted
until (seemingly) chaotic motion was observed.
Arguments
References
William Constantine (1999),
Ph.D. Dissertation: Wavelet Techniques for Chaotic and Fractal Dynamics,
Mechanical Engineering Department, University of Washington.