Fatigue life prediction of vulcanized natural rubber subjected to heat-aging

Fatigue life prediction and evaluation are the key technologies to assure the safety and reliability of automotive rubber components. In this paper, fatigue life prediction methodology of vulcanized natural rubber was proposed by incorporating the finite element analysis and fatigue damage parameter determined from fatigue test. Heat-aging effects on the fatigue life prediction of natural rubber were experimentally investigated. Fatigue test were performed using the 3-dimensional dumbbell specimen, which were aged different amounts. The Green-Lagrange strain at the critical location determined from the finite element method used for evaluating the fatigue damage parameter. Fatigue life prediction equation effectively represented by a single function using the Green-Lagrange strain. According to fatigue life prediction equation, fatigue life ambient temperature was longer than at 70 ∘C. Predicted fatigue lives of the rubber component were in fairly good agreements with the experimental fatigue lives within factor of two.