Failure Criteria for Filamentary Composites

\A two-level, linear, semiempirical theory for a failure criterion is described. The theory predicts the strength behavior of unidirectional filamentary composites under uniaxial and combined stress from basic constituent material properties and fabrication process considerations. Applications of the theory to several filament-nonmetallic ma-i I- 'C ' < • / ■ trix composites'are presented and comparisons are made with experimental data. These <-,.'« ■ ;• ' . • i:- .■■■'/., results show good agreement between theory and experiment. Simple and combined 0--1-. A r.:-.--* '. ^ 0 strength envelopes are generated to illustrate the versatility of the theory and to point out s-'".--..-'■/*! ■ / •- problem areas in experimental work and design.