Characterisation of large strain viscoelastic properties of polymers

Abstract

The most widely used approach to model the large strain elastic and the time-dependent response of polymers in a finite element simulation is the application of the so-called hyper-viscoelastic material model, which is composed of a nonlinear elastic (hyperelastic) and a linear viscoelastic part. In order to determine the constitutive parameters, a simple numerical algorithm has been used here. This method ensures a general strategy to fit the material parameters directly and accurately to the measurements. In this study, the material model and the numerical algorithm have been tested for silicone rubber and polypropylene. Finally, the numerical solutions have been compared with stress relaxation tests.