21711 The Research on Mechanical Vibration Reduction using The Visco-Elastic Dynamic Vibration Absorber

Visco-elastic vibration isolators are widely used as vibration isolating member. In this study, optimal vibration control of vertical vibration body using dynamic vibration absorber of a mass and a visco-elastic are analyzed theoretically and confirmed experiment. Vibration analysis and experiment of the two-degree-of-freedom system which installed one dynamic vibration absorber at the primary system and the three-degree-of-freedom system which parallelly installed two dynamic vibration absorbers at primary system were carried out. In the case of the three-degree-of-freedom system are the waveform equal to the two-degree-of-freedom system is shown, when spring constant ratio and mass ratio are adjusted. Vibration reduction effects (vibration transmissibilities) are measured experimentally. The results show good agreement with calculated ones. As a conclusion, it is possible to do two dynamic vibration absorber vibration reduction well, when the dynamic vibration absorber can not be installed in center of gravity of oscillating body.