Rubber fatigue prediction for filled natural rubber under positive and negative R ratios

An effective tensile strain epsilon(t) for rubber fatigue under positive and negative ratios was proposed for the design of rubber products in the industry. It was applied to the cylindrical specimens over 30 fatigue cases: achieved the predicted points within a scatter band of 0.5 with R-2 = 0.85. Further application to the ring specimens on 90 fatigue cases including different loading modes and phase angles: achieved the prediction within a scatter band of 1.7. Critical locations were correlated with the maximum values of epsilon(t). The novel approach without additional fitting variables can be used in engineering design and applications.