Fatigue life prediction of vulcanized natural rubber under proportional and non‐proportional loading

Abstract

To investigate the multiaxial fatigue properties of vulcanized natural rubber (NR), a series of tests including both proportional and non‐proportional loading paths on small specimens were performed. The existing fatigue life prediction approaches are evaluated with life data obtained in the tests. It is shown that the equivalent strain approach presents a good prediction of the fatigue life although it has a certain shortcoming. Compared with the strain energy density (SED) model, the cracking energy density (CED) model represents the portion of SED that is available to be released by virtue of crack growth on a given material plane, so it gives better results in the life prediction. Some of the approaches based on critical plane which are widely used for metal fatigue are also tested in this paper, and the results show that the Chen‐Xu‐Huang (CXH) model gives a better prediction, compared with the Smith‐Watson‐Topper (SWT) and Wang–Brown (WB) model. A modified Fatemi–Socie's model has also been introduced, and the results show that the modified model can be used to predict the fatigue life of rubber material well.

Evaluation of multiaxial fatigue life prediction criteria for PEEK

“…While Fatemi and Socie (FS) [16] built their work on this model but proposed that the normal strain term should be replaced by normal stress so as to account for the effect of mean stress. This approach has been proven effective for a variety of materials [29][30][31][32]. For materials showing normal fracture, Smith et al (SWT) [18] suggested that the maximum normal strain plane should be considered as the critical plane.…”

Fatigue behavior characterization and life prediction for elastomeric components

“…According the stress-strain curve fitting of the experimental data, the curve significantly changed during the first five load cycles, especially for the cycle between the first and the second, the stress rapidreduceand gradually got stable in the next cycles, as shown in fig 2, the phenomenon of cyclic stress softening was called Mullins effect, which was a quite important issue for finite element analysis and fatigue failure criteriachoice of rubber components [6].…”

Numerical methods of multiaxial fatigue life prediction for elastomers under variable amplitude loadings

“…In this paper, the three‐term Ogden model is used to express the strain energy density function as where λ 1 , λ 2 and λ 3 are principal stretches and μ i and α i are material properties of the elastomer. Table lists the mechanical properties of an Ogden hyperelastic material as suggested by Wang et al The properties of elastomers considering the Mullins effect are estimated by comparing the stress values between the initial stage and the stabilized stage in the uniaxial fatigue tests performed by Wang et al Because stress linearly depends on μ i , in the Ogden model, a scale factor is applied to μ i in order to consider the Mullins effect.…”