Ductile crack growth in poly(ethylene terephthalate) film

Abstract

A study of crack growth in a poly(ethylene terephthalate) film has been made to check the applicability of fracture mechanics and to devise a suitable technique for assessing the fracture toughness of ductile thermoplastics. A combination of mechanical tests and microscopic examination has shown that fracture mechanics, in a simple single-parameter form, cannot be applied to this material. It is concluded that, because careful tensile tests on unnotched specimens can give so much useful information, it is worth considering whether tests on sharply notched specimens are desirable.