Experimental Evidence of Vibrational Resonance in a Mechanical Bistable Twin-Well Oscillator

Vibrational resonance (VR) is a nonlinear phenomenon which occurs when a bistable system is subjected to a biharmonic excitation consisting of a small-amplitude resonant excitation and a large-amplitude high-frequency excitation. The result is that, under some conditions, the high-frequency excitation amplifies the resonant response associated with the slow dynamics. While VR was studied extensively in the open literature, most of the research studies used optical and electrical systems as platforms for experimental investigation. This paper provides experimental evidence that VR can also occur in a mechanical bistable twin-well oscillator and discusses the conditions under which VR is possible. The paper also demonstrates that the injection of the high frequency excitation can be used to change the effective stiffness of the slow response. This can be used for amplification/deamplification of the output signal which can be useful for sensitivity enhancement and/or vibration mitigation.