A material model for rubber-like polymers exhibiting plastic deformation: computational aspects and a comparison with experimental results Original Research Article

A finite element formulation is derived, which accounts for materials exhibiting plastic flow after large elastic deformation. Such material behaviour can be observed, for example, in certain kinds of rubber useful in practical situations due to their high tensile strength and resistance to aging. For these materials, then, both the elastic and plastic behaviour must be described by a non-linear material model. Because of this, the return mapping algorithm used in this work requires the solution of several non-linear equations in every Gauss point, which is carried out here via Newton iteration. The fitting of the material model to experimental results demonstrates the necessity of incoporating finite elasticity into the material model in order to successfully account for the observed material behaviour. The conseqence of using an oversimplified elastic material model is demonstrated by means of examples.