The Resistance of Rubber Compounds to Brittle Crack Propagation

Abstract

Abstract 1. A theory based on irreversible thermodynamics and minimal entropy production principles is presented. This constitutive model introduces a methodology to describe fatigue-crack propagation behavior in natural rubber vulcanizate over the entire range of the elastic-energy release rate. 2. The utility of this model has been proved and demonstrated in view of the establishment of the damage evolution coefficient μ and the energy barrier μTc−T for one rubber compound. 3. The theory calls for quantitative measurements of the amount of damage associated with crack advance in order to extract the specific enthalpy of damage, γ*. This true material parameter, γ*, which characterizes its resistance to crack propagation (fracture toughness) can be related to the microstructure of the material. Thus a useful microstructure-fracture-toughness relationship based on the present theory can be constructed. Such a relationship can guide the development of rubber compounds with superior fracture toughness.