Effect of material and mechanical parameters on the stress-softening of carbon-black filled rubbers submitted to cyclic loadings

Several carbon-black filled Styrene Butadiene Rubbers (SBR) were tested in cyclic uniaxial tension in order to investigate their cyclic stress-softening. A classic representation using the maximum stress with respect to the number of cycles is first applied to present the experimental data. Nonetheless, the limiting interest of such a representation drove us to propose an original method of cyclic softening characterization for filled rubbers. The method is based on the use of stretch amplification factors. The characterization method provides an interesting tool for the study of the effect of material parameters and loading parameters on the cyclic softening of filled rubbers, as reveals the current study conducted on several SBRs with various amount of fillers and different crosslink densities.