Prediction and three-dimensional Monte-Carlo simulation for tensile properties of unidirectional hybrid composites

A 3D fiber tow-based analytical model incorporating shear-lag theory and a statistical strength distribution has been used to simulate the tensile properties and predict the tensile strength of unidirectional hybrid composites. Also, we have developed an expression of interfacial shear stress between tows for the simulation. The hybrid composites considered in this study contain two different types of fiber tows (glass/epoxy and carbon/epoxy tows) that are intimately mixed in a random pattern throughout the composite. The tow is defined as a fiber/matrix system (an impregnated tow) rather than a bundle of fibers. The properties of the tows used in the analytical model are derived using the rule-of-mixtures from the properties of the constituent materials and their volume fractions. For low levels of carbon fiber reinforcement, the low strain to failure of the carbon fibers can initiate failure and actually have a detrimental effect on strength. Otherwise, the study indicates that there are no synergistic effects of hybridization on the tensile properties, which consequently can be described for the most part using the rule-of-mixtures.