Fracture of polymers in biaxial and triaxial tension

Abstract

Macroscopic fracture is preceded by localized deformation and rupture processes that depend on the state of combined stress (i.e., on the stress state) and other test conditions as well as on polymer structure and morphology. To illustrate the effect of stress state on the mode of fracture initiation and crack growth, data obtained on elastomers in triaxial tension are reviewed along with those for an unfilled styrenebutadiene rubber vulcanizate in simple tension, equal biaxial tension, and under the biaxial tensile conditions that give a pure shear deformation. The behavior of plastics, including the dependence of the strength of a notched specimen on its thickness, is briefly considered.