# 1995 Edinburgh
A new method based on the Dugdale zone solution for finite geometries is presented to analyse the case of craze growth at the notch tip in Charpy impact experiments. It is believed that correct values of initiation toughness are calculated via this method, leading to greater confidence in the extrapolation technique used to derive the plane strain fracture toughness for polyethylene at high impact speeds. An extensive comparison of the fracture performance of a PEE0 and a PE100 resin has been performed using this approach. There is no difference in minimum plane strain fracture toughness between the grades, but the PE100 resin has far superior resistance to crack initiation by virtue of higher energy absorption through crazing.