ABSTRACT
The determination of failure conditions for fiber-reinforced composite materials is one of the most critical subjects in structures research, and many empirical as well as semianalytical criteria have been proposed. However, models to predict composite failure based on micromechanical analysis are few and far between because of its complicated nature, which calls for more extensive study on failure mechanism of fiber composites. Failure envelopes of unidirectionally reinforced composite materials are derived based on micromechanics. Each fiber is modeled as an isotropic cylinder embedded in an isotropic medium that renders the whole composite transversely isotropic. The material is transversely isotropic and the envelopes represent the allowable states of axial stress that may act in the plane of isotropy. The envelopes presented represent composites with fiber volume fractions of 0.1, 0.3 and 0.6.
