Fatigue Life Analysis of Rubber Vibration Damper Based on Continuum Damage Model

Based on the continuum damage mechanics theory, rubber-like material fatigue life prediction method is researched. Using the first order Ogden strain energy function, a fatigue damage evolution equation of rubber material is derived and a fatigue life prediction model for rubber with equivalent strain range as damage parameter is built. Fitting tensile stress-strain data of unnotched specimen, Ogden hyperelastic constitutive model parameters of rubber materials are obtained. The principal stress distribution of an arm rubber bushing under fatigue loading is calculated by finite element structural analysis. Using equivalent stress method of rubber hyperelastic materials and the tensile stress-strain data of unnotched specimen, the equivalent strain range calculation method of rubber vibration damper under multiaxial stress state is put forward and the equivalent strain range of the arm rubber bushing is calculated. The model is used to predict the fatigue life of rubber bushing and verified by fatigue bench test result. The result shows that the predicted fatigue life is the fatigue test life of 1.96 times. So, the prediction accuracy is good.