21310 The most suitable values of visco-elasitic dynamic vibration absorber and forced vibration response

Rubber vibration isolators (R.V.I) are widely used as vibration isolating member. In this paper, optimal vibration control of vertical vibration body using dynamic absorber consist of a mass and a rubber element are analyzed theoretically and confirmed experiments. The spring elements for both the primary system and the secondary vibration system of equivalent models with two-degree-of-freedom vibration isolator system are assumed to be rubber elements which have complex spring constant. When the primary system has a loss factor, the optimal values are derived by a mass ratio variation method using the numerical calculation. Vibration reduction effects (vibration transmissibilities) are measured experimentally. The results show good agreement with calculated ones. It is concluded that the complex spring model can be explained well for optimal vibration control with vertical vibration isolator system