Abstract
Recently, the viscoelastic dynamic vibration absorbers(VDVA) are being studied. The VDVA consist of a mass and a viscoelastic element. The almost studies on VDVA was optimization of the amplitude of a main system subject to the parameters of dynamical properties of the model used in the VDVA. But it is difficult to obtain a viscoelastic material which has the optimum values of the parameter of dynamic properties. The VDVA using a polymeric material which viscoelasticity is known can be optimized subject to a shape parameter of the material. It is, however, known that the natural frequency of the main system which demonstrates the most favorable vibration reduction performance with the optimized VDVA is limited to near a certain frequency. In this study, the VDVA which combined the polymeric materials of two kinds of viscoelasticity of which frequency characteristics have been given by the fractional dynamic model, are proposed and optimized subject to two shape parameters of the materials. Used polymeric materials are acrylic rubber, chloroprene rubber, and isoprene rubber. As a result, the natural frequency range of the main system which demonstrates the most favorable vibration reduction performance was expanded. With the national frequency range was 2Hz to 400Hz with acrylic and chloroprene rubber, and 2Hz to IkHz with acrylic and isoprene rubber.
