Abstract
A wide range of nylon materials, with combinations of fibre reinforcement and rubber toughening, have been subjected to a large number of fracture tests. The interactions between additions of fibre and rubber have been studied in order that these materials may be optimised for toughness. The measured toughness was observed to be strongly dependent upon the test method. Toughness measurements were made at varying temperatures and strain rates. The toughness was reduced by small fibre additions, but increased by large fibre additions. Further increases in toughness were induced by rubber toughening, but this effect is confined to fast fracture situations.