Abstract
This paper deals with the vibration quenching problem of the single-degree-of-freedom system with a limited power supply using a Hula-Hoop and displacement magnification mechanism. This system is forced by the centrifugal force of rotating unbalance. If the unbalance is small, the amplitude of vibration becomes small and Hula-Hoop does not rotate. Therefore, displacement magnification mechanisms are adopted. In this study, the quenching effect in large frequency region containing the frequency larger than the second-order natural frequency, which was created by the installation of the displacement magnification mechanism, are studied. Following was made clear by the numerical integration of the equation of motion and the experiment: (1) In the device using Hula-Hoop and displacement expanding mechanism, quenching at a frequency higher than the second-order natural frequency. (2) Its quenching principle is that the vibration mode becomes the shape of the first mode by the centrifugal force of both unbalance and Hula-Hoop, therefor, as the vibration frequency and the natural frequency of the first mode become apart, the response amplitude becomes smaller. (3) The vibration quenching effect is large in the frequency range slightly larger than the natural frequency, in both the first mode and the second mode.
