ABSTRACT

ABSTRACT: As success is achieved in modeling individual aspects of rubber’s stress strain response such as nonlinear elasticity, the Mullins effect, the Fletcher/Gent/Payne effect, and viscoelasticity, it is becoming possible to contemplate increasingly realistic models that simultaneously embody many aspects. Before such models can gain wide currency, however, they should be demonstrated to compare favorably against experimental results that probe a correspondingly complex set of aspects. This paper presents the results of an experiment involving combined axial and shear cyclic straining. The desired strains were achieved by extending and twisting an annular ring of filled NR. The strain and stress histories include pre-conditioning events, as well as cycles of varying amplitudes where the axial and shear deformations are applied both in phase and out of phase. Also, the effect of a static axial load on the dynamic shear response is measured. It is hoped that developers of constitutive models may find a useful and challenging benchmark in these results.