Abstract: Based on the measured fatigue life of dumbbell cylindrical specimen, seven fatigue life prediction models using different damage parameters for predicting fatigue life of rubber isolators is presented. The damage parameters presented in this paper include the maximum principal engineering strain, maximum principal logarithmic strain, maximum principal Green-Lagrange strain, octahedral shear strain, strain energy density, Luo stress, Saintier stress. To investigate the effect of different damage parameters on the predicting fatigue life of rubber isolators, seven proposed prediction models are used to predict the fatigue life of a typical powertrain rubber mount. The fatigue life of the mount predicted by the seven models is estimated and is compared with the experimental fatigue life. The fatigue life calculated using the models with maximum principal engineering strain, maximum principal logarithmic strain, maximum principal Green-Lagrange strain, octahedral shear strain or strain energy density as the damage parameter is in agreement with the experimental fatigue life within a factor of four. The model using Luo stress or Saintier stress as damage parameter can predict the fatigue life within a factor of two, which is better than the other models. It’s concluded that the proposed model for fatigue life prediction with the Luo stress or Saintier stress can be used to estimate the fatigue life for rubber isolator.

Key words: damage parameters, fatigue life, prediction model, rubber isolator