ABSTRACT
The present contribution deals with the thermomechanical modelling of a foamed rubber material including the experimental characterisation. In our case, a mixed open and closed cell porous material, consisting of an EPDM-bulk matrix with air filled pores, is investigated. This kind of material is mainly used as a sealing component in automotive applications, e.g. door seals or gaskets in the engine compartment. The sealing effect is mainly provided by multiaxial deformations due to local compressibility in contact with the sealing surface. Consequently, the experimental methods in this work are given by general biaxial tensile tests and hydrostatic compression tests. Furthermore, investigations regarding the temperature dependence of the material are executed with respect to applications in thermally loaded fields like the engine compartment. Besides the evaluation of the described experiments, the modelling of the viscoelastic porous material is challenging. Due to the structure of the material, a model based on the theory of porous media and the theory of mixtures is used. The material’s point of compaction is modelled by an additive compression-term. A multiplicative split of the deformation gradient allows a separate identification of elastic and time dependent material parameters. A similar approach finds application to identify volumetric and isochoric deformations. The parameters identified at room temperature are modified afterwards in order to take temperature dependence into account.
