Strain induced transient effects of filler reinforced elastomers with respect to the Payne‐Effect: experiments and constitutive modelling

Abstract

AbstractFiller‐reinforced rubber shows many interesting nonlinear effects under cyclic deformations. As a result of the dynamic loading, a change in the materials' microstructure and hence in the dynamic behaviour of the elastomer is observed. In this context, the frequency‐, amplitude‐, temperature‐, and the preload‐dependence are well‐known effects. Additionally, pronounced thermomechanical couplings are observed, e.g., heat build‐up phenomena. Mechanical coupling effects can be demonstrated by studying the transient dynamic behaviour of the Payne‐effect (amplitude dependence). Using the technique of dynamical mechanical analysis (DMA) the mentioned effects can be investigated in a very comfortable way. To study the process dependence of the dynamic modulus, bimodal DMA tests and transient multistep tests have been carried out. The non‐trivial postprocessing of the bimodal measurements is shortly explained in the paper. The approach of finite nonlinear viscoelasticity with additional internal variables provides an excellent basis for constitutive material modelling. The thermodynamical consistency of the developed constitutive model is demonstrated. This offers the possibility to represent thermomechanical coupling effects like the dissipative heat build‐up. A series of numerical results of FEM simulations under more complicated transient loading histories, computed with the developed and implemented material model, are presented.