On the dynamics of a vibration isolator with geometrically nonlinear inerter

Abstract

The inerter is a two-terminal mechanical element that produces forces directly proportional to the relative acceleration between these terminals. The linear behaviour of this element has already been described in the literature. In this work, the nonlinear effects of the geometrical arrangement of the inerter are investigated in terms of vibration isolation and compared to the traditional arrangement. The analysis comprises the use of harmonic-balanced method applied to the exact equation, as well as approximations for low amplitude and high amplitude. Numerical analysis is used to complement the investigation. Comparison with classic vibration isolators shows possible benefits for high frequency regimes. The effects from the geometrical nonlinearity vanish when the amplitude of motion is large.