The stress and sonic modulus versus strain curve of polymer fibres with yield

摘要

The stress vs. strain curve with yield and the sonic modulus vs. strain curve of fibres of linear polymers below the glass transition temperature are modelled by the continuous chain model in combination with a simple yield model. It is supposed that yield of polymer fibres is due to shear deformation of the domains. The yield model is based on a critical shear yield strain. A good agreement between the experimental tensile and sonic modulus vs. strain curves and the theoretical curves has been obtained for a selection of poly(p-phenylene terephthalamide) and poly(ethylene terephthalate) fibres.