Experimental Testing of a Bi-stable Point Wave Energy Absorber Under Harmonic Waves

The hypothesis that a bi-stable nonlinear restoring element will help reduce the sensitivity of a point wave energy absorber’s response to variations in the frequency and amplitude of the incident waves is supported by many previous theoretical investigations. In this study, the hypothesis is investigated experimentally by designing, fabricating, and assessing the response behavior of a prototype bi-stable wave energy absorber excited by harmonic incident waves in an experimental wave flume. Results demonstrate that bi-stability does not seem to improve the size of the effective bandwidth over the linear design. Nonetheless, a key advantage remains in the ability of the bi-stable restoring force to push the effective bandwidth of the wave energy absorber toward lower frequencies, where most of the wave energy is trapped.