On the modelling of non-linear elastomeric vibration isolators

Abstract

Vibration isolators consisting of polymeric materials exhibit non-linearity in their stiffness and damping characteristics. Two different approaches towards modelling these non-linear characteristics are discussed. In one approach, experimentally obtained hysteresis loops are modelled through a suitable constitutive equation. In the other, experimentally obtained harmonic, displacement transmissibility plots are modelled by expressing the restoring and damping forces through lower order polynomials of deformation and rate of deformation, respectively. In both cases, it is observed that the dynamic stiffness, which is more than the static stiffness, exhibits a small softening type non-linearity. The non-linearity in the damping characteristic is seen to be more pronounced than that in the stiffness.