A Novel Methodology to Determinate Material Parameters of Nonlinear Strain Rate Dependent Constitutive Model of Polymers

The Ramaswamy-Stouffer constitutive model modified by Goldberg is used as a strain rate dependent nonlinear model to predict polymer behavior in the different loading conditionsand various strain rates. In comparison with other suggested constitutive models, the presented model is more general andprecise, but its original methodology for estimating material parameters requires some pure shear and tensile tests in different strain rates and this makes utilization of this modelcostly and difficult. In this research, by performing parametric studies, the effects of material parameters are investigated.Moreover,a methodology based on one quasi-statics tensile test is proposed and compared with the available experimental data. A comparison between the experimental results and modeling data shows a good agreement