Abstract
This paper proposes a new method for the utilization of variable damping in a vibration system. A single-degree-of-freedom base-excited model with a variable damper is considered. The coefficient of variable damping can be changed as that in the case of a sine wave, i.e. parametric excitation whose frequency can be arbitrarily selected. One of the external forces acting on the mass through the damper from the base is equivalent to the product of the damping coefficient and the input velocity. By multiplying the input sine wave by the frequency-controlled sine wave of variable damping, a new vibration that has a frequency different from the input frequency arises. Therefore, the oscillation of the damping coefficient at a suitable frequency can generate a new vibrational component that has the same frequency as the eigen-oscillation of the vibration system. As a result, the vibration amplitude increases because of resonance. In this paper, we confirm the growth of the vibration amplitude by the proposed parametric excitation of damping by simulation and experiment.
