Abstract
The influence of viscoelasticity of rubber materials on the performance of rubber isolators is presented. Dynamic properties of both neat rubber and filled rubber with filler content φ<φ are linear viscoelastic while those of filled rubbers with filler content φ≥φ <sub>c</sub> are strongly strain dependent and nonlinear viscoelastic. The Kramers & Kronig relationship and its approximation is used to simulate the performance of a linear viscoelastic rubber isolator. Two specific conditions for viscoelastic rubber systems, (a) systems with constant loss tangent and (b) systems in the region of ω <sup>0.5</sup> frequency dependence, are studied. The limitation on the transmissibility of a linear viscoelastic rubber isolator is also illustrated through the Kramers & Kronig relationship. The performance of a vibration isolator made from filled rubbers with filler content φ≥φ <sub>c</sub> however, can be simulated by the L-N-B model. When the strain amplitude at natural frequency is greater than the apparent strain amplitude ∈ <sub>app</sub> , the stability problems such as Jump effect are likely to happen. © 1998 American Institute of Physics.