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

Rubber fatigue prediction under positive and negative R ratios . • Critical locations were correlated with the maximum value of ε t from both the cylindrical and ring specimens. • The criterion achieved R 2 of 0.85 in an S-N form with a scatter band of 0.5 over 30 fatigue cases under different R ratios. • 96.7% of the predicted data within the measured fatigue band with a scale factor of 2 on the cylindrical samples. • The criterion was validated on 90 fatigue cases with 15 paths and all predicted points were within a scatter band of 1.7. • This potential novel approach without additional fitting variables would save significant time and cost in industry. An effective tensile strain ε 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 ε t . The novel approach without additional fitting variables can be used in engineering design and applications.