Analysis and application of a nonlinear vibration absorber

The authors investigate theoretically and experimentally the performance of a recently developed quadratic vibration absorber that is based on the saturation phenomenon. They consider the problem of controlling the vibrations of a single-degree-of-freedom plant, develop the equations governing the response of the closed-loop system, and obtain an approximate solution. They investigate the strategy by studying its steady-state characteristics and comparing its performance with that of a linear tuned absorber. Then, they implement both techniques experimentally using a digital signal processing device. The authors develop a software algorithm that allows for automatic real-time tracking of the system response. They use both techniques to control high-amplitude responses of a cantilever beam fitted with piezoceramic actuators. When each absorber's frequency is tuned properly, they show that both schemes possess similar suppression bandwidths. In addition, they demonstrate that the power requirement of the quadratic absorber can be reduced by judicially modifying its control signal.