Filler effects on the heat build-up of filled rubbers during fatigue: Experimental observations and constitutive modeling

In the present contribution, the constitutive model is extended to account for the effect of fillers, such as carbon-black, on the heat build-up. A Zener-type rheological model is used to describe the thermo-mechanical behavior of filled rubbers, the strain response being decomposed into two components: a thermal resistance linked to the stress-free thermal-dilatation, and a mechanical resistance linked to the large strain visco-elastic material behavior. In order to take into account the filler effect on the thermo-mechanical response, a stretch amplification factor is introduced in the model formulation. Furthermore, the existence of a dissipation pseudo-potential, function of a viscous dilatation tensor related with the time-dependent response, is postulated.