Rubber fatigue evaluation for antivibration products and an S–N curve with a scatter band of 0.8

Abstract

Rubber antivibration products are widely used in engineering structures. An accurate evaluation on fatigue performance is a challenging issue during a design procedure. In this article, an effective stress approach was applied to multi-directional snubbing (MDS) mounts, AE2 and AE42 specimens. It was demonstrated that observed fatigue cracks were initiated at a place where the maximum effective stress was located. There were confirmed strong correlations between the effective stress and the number of failed cycles: R² = 0.994 for AE2 with eight fatigue cases, R² = 0.955 for AE42 with 16 cases and R² = 0.917 for both AE2 and AE42 with 24 cases. A valuable S–N curve (covering from 2 × 10² to 3 × 10⁶ cycles) of rubber (SBR with 67 hardness) was obtained (a scatter-band range of 0.8 with an average standard deviation of 14.3%). The scatter band includes both natural fatigue scattering and criterion accuracy. Less than 10% CPU time, compared with the critical plane search method, would only be required for evaluation on a fatigue case of a two-dimensional solid. These findings have shown that the proposed approach is reliable and can be considered in a suitable fatigue design stage. As the presented criterion was validated in limited contexts, more cases in antivibration design are required to support this approach.