A study on the fatigue life prediction and evaluation of rubber components

摘要

The fatigue analysis and lifetime evaluation are very important in design procedure to assure the safety and reliability of the rubber components. The interest of the fatigue life of rubber components such as the transmission mount is increasing according to the extension of warranty period of the automotive components. In this study, the fatigue lifetime prediction methodology of the vulcanized natural rubber components was proposed by incorporating the finite element analysis and fatigue damage parameter determined from fatigue tests. Nonlinear finite element analyses of the 3D dumbbell specimen of natural rubber and rubber component were performed based on a hyper-elastic material model determined from the simple tension, pure shear and equi-biaxial tension tests. The Green-Lagrange strain at the critical location determined from the finite element analysis was used for evaluating the fatigue damage parameter of the rubber components. Fatigue tests were performed using the 3D dumbbell specimens with different levels of maximum strain and hardness. The basic mechanical properties test and the fatigue test of rubber specimens were conducted in an ambient temperature. Fatigue life curves can be effectively represented by a following single function using the maximum Green-Lagrange strain. Fatigue lives of the rubber components are predicted by using the fatigue damage parameters at the critical location. Predicted fatigue lives of the rubber components agreed fairly well with the experimental fatigue lives a factor of two.