A framework for analyzing hyper-viscoelastic polymers

Abstract

Hyper-viscoelastic polymers have multiple areas of application including aerospace, biomedicine, and automotive. Understanding their mechanical responses is therefore extremely important, particularly because they often exhibit strong rate and temperature dependence, including a low temperature brittle transition. Relationships between the response at various strain rates and temperatures are investigated and a framework developed to predict response at rates where experiments are unfeasible. A mas-ter curve showing the rate dependences of the storage and loss moduli at a reference temperature is constructed using the results of a dynamic mechanical analysis (DMA) experiment. A frequency sweep spanning two decades and a temperature range from pre-glass transition to pre-melt is used. A fractional derivative model is fitted to the experimental data, and this models parameters are used to show how the stress-strain relationships at a desired strain rate could be derived.Hyper-viscoelastic polymers have multiple areas of application including aerospace, biomedicine, and automotive. Understanding their mechanical responses is therefore extremely important, particularly because they often exhibit strong rate and temperature dependence, including a low temperature brittle transition. Relationships between the response at various strain rates and temperatures are investigated and a framework developed to predict response at rates where experiments are unfeasible. A mas-ter curve showing the rate dependences of the storage and loss moduli at a reference temperature is constructed using the results of a dynamic mechanical analysis (DMA) experiment. A frequency sweep spanning two decades and a temperature range from pre-glass transition to pre-melt is used. A fractional derivative model is fitted to the experimental data, and this models parameters are used to show how the stress-strain relationships at a desired strain rate could be derived.