Fatigue Life Simulation of Short Glass Fiber/Rubber Composites Using the Damage-Entropy and Self-Heating Concepts

To predict the fatigue life of materials under cyclic loading, some research works have used the temperature rise caused by self-heating. The current paper presents a model based on the damage-entropy and self-heating concepts to predict the fatigue life of rubber and rubber composites. To this end, laws of thermodynamics were utilized to relate the material's temperature rise to its damage. The existing entropy-based model was modified to predict the fatigue life of SFRCs by incorporating the concept of damage entropy. The present model, which considers the material's viscoelastic energy, stored energy, and wasted energy and calculates the damage entropy in each loading cycle, was rigorously tested through an extensive experimental program. The experimental results demonstrated the model's accuracy in predicting the fatigue life of rubber and rubber composites at the applied strain below 88%.