Abstract
This study proposes a new semi-active base-isolation system using harmonically varying damping (parametric excitation of damping) and having a filter consisting of the neural oscillators. The harmonically varying damping is the oscillation of the damping coefficient by using a variable damper and can shifts the frequency of the damping force by the frequency modulation. The new semi-active vibration control method using this parametric excitation of damping induces interference among structural vibration components by the controlled parametric excitation of damping, and the effect of the interference can reduce the vibration amplitude of structure excited by multiple frequency input. The key technology is extracting the designated frequency components from external input or structural vibration to modulate the frequency of the damping force to an appropriate frequency for the parametric excitation of damping. In this study, we use neural oscillators, called FitzHugh oscillators, as the filter to extract the frequency component, because such nonlinear oscillators have synchronization property with periodic external input in a frequency region close to the natural frequency of the oscillator. We show the special configuration of the neural oscillators for frequency modulation in this paper. The viability of the proposed system is tested in numerical simulation.
