The importance of viscoelastic materials has been increasing in engineering applications such as vibration-absorbing devices and shock-absorbing devices. The author has studied the dynamic behavior of silicone gel which is an important vibration-and shock-absorbing viscoelastic material. This material shows high performance in absorbing vibrations and shocks from the mechanical systems to which the material is applied. The measured complex shear moduli of the silicone gel have suggested that the silicone gel can described by a generalized Voigt model. The objective of this paper is to elucidate the fundamental characteristics of the oscillator composed of the silicone gel and a mass. The fractional time-derivative Voigt model of the silicone gel and the equation of motion of a single-degree-of-freedom (SDOF) oscillator having the fractional derivative term are derived. The fundamental characteristics of the equation of motion are studied through frequency response functions and characteristic roots. Transient analyses of the equation of motion are also conducted by the discrete Fourier transform and by a new time integration method.
