Abstract
Structural parameters derived from absolute intensity small-angle X-ray scattering experiments have been combined with strength and failure strain data for pan carbon fibres in an elastic/plastic theory of fracture. Good quantitative agreement with the theory is obtained throughout the heat treatment temperature range of 1000-2800 degrees C. The application of a modified griffiths theory, including a plastic work term, gives more qualitative agreement. The influence of the microstructure, in the form of crystalline ribbons, elongated micropores, and non-organized carbon and nitrogen, is discussed in relation to the fibre failure strain. The influence of grosser internal flaws on mechanical properties is also considered.

This publication has 17 references indexed in Scilit: