Analysis of Fiber/Matrix Interface in Unidirectional Fiber-Reinforced Composites

ABSTRACT: Finite element models are used to analyze a quarter of unit cell for a unidirectional lamina. Effective lamina properties obtained from a micromechanics model were used to compare with the FEM results. Stresses at the fiber/matrix interface are determined for longitudinal and transverse tension load and combined tension and thermal load. Strain energy release rates are calculated for various degrees of fiber/matrix debonding under tension, transverse, thermal and their combined loading conditions. Variations of strain energy release rates along the interface indicate that completely debonding along the fiber/matrix interface of the circumference of the fiber is unlikely. Finally, the loss in stiffness due to the aforementioned load cases is predicted