A method to develop a unified fatigue life prediction model for filled natural rubbers under uniaxial loads

Abstract

Rubber components are widely used in many fields because of their superior elastic properties. Fatigue failures, commonly encountered in rubber components, however, remain a critical issue. In this study, the effect of strain ratio R on the fatigue life of filled natural rubbers used in automotive mounts is investigated experimentally and numerically. A uniaxial tension/compression fatigue experiment was conducted on dumb‐bell cylindrical rubber specimens subject to loads representing different R ratios. The experimental fatigue data are used to formulate two preliminary fatigue models based on peak strain and strain amplitude as the damage parameters. The deficiencies of these two models in predicting fatigue life over a wide range of R ratios are discussed, and an alternative life prediction model is proposed. The proposed model incorporates the effect of R ratio using an equivalent strain amplitude. It is shown that the proposed model could effectively predict fatigue life over a wide range of R ratios with an improved accuracy.

Fatigue life prediction for vibration isolation rubber based on parameter‐optimized support vector machine model

“…Numerous factors affect the fatigue performance of rubber, such as load history, ambient temperature, ozone concentration, and compound formula (such as filler volume fraction and rubber type). Multi‐factor rubber material fatigue test is difficult because of the small test data sample points and large dispersion . To establish a quantitative analysis model of rubber material fatigue life, finding a mathematical model that can maximize scarce sample data is necessary.…”

Crack precursor size for natural rubber inferred from relaxing and non-relaxing fatigue experiments

“…Other details of the experiments conducted are available in Ref. [13]. The dimensions of the dumbbell cylindrical component and the rubber material parameters are obtained from previous studies done by Shangguan et al [13] together with experimental fatigue life data.…”

“…In this section, the fatigue life data reported previously [13], as shown in Table 1, are used to verify the self-written algorithm and the effectiveness of the Mars-Fatemi model.…”

“…There are two points to note: First, the crack precursor size is set equal to 35.7 lm, which is the mean size of inferred initial cracks calculated in Section 4.2. Second, the fatigue life and corresponding R ratio under three different peak strain levels [13] shown in Table 2 are used to determine the relation between the power law exponent F and the R ratio.…”

“…Test variability will reflect the natural variation of crack precursor sizes existing in the material [12]. Certain efforts have been made with some success to use the S-N method for estimating the fatigue life of rubber components filled with carbon black [10,13,14].…”