ABSTRACT
Typical elastomer components like tires, sealing rings, suspensions or engine mounts are exposed to different environmental influences, which can lead to changes in material properties. This is caused by irreversible modifications occurring in the elastomer network which is known as chemical ageing (Ehrenstein & Pongratz 2007). In this work, ageing behavior of Nitrile Butadiene Rubber (NBR) is investigated under the influence of different surrounding media as air and oil. Based on previous published works, in which chemical ageing was also modeled, a continuum mechanical approach is introduced here, whereby the rubber thermo-viscoelasticity is taken into account. Components produced from NBR are used in many industrial applications where dynamic loads also take place. For these reasons, a dissipative heating of such components occurs (cf. Johlitz et al. (2016)). The resulting temperature field can lead as an accelerator for chemical reactions, triggering the chemical ageing. Thus, the couplings between these two phenomena are also taken into account. Based on the example of NBR an illustrative boundary value problem is numerically solved using FEM and the results and properties of the model are discussed.
