MODELING OF THE RELATIONSHIP BETWEEN MORPHOLOGY AND VISCOELASTIC BEHAVIOR OF UNIDIRECTIONAL FIBER-REINFORCED POLYMERS

A new approach is proposed to predict the relationship between geometr ic arrangement of fibers within the polymer matrix and viscoelastic be havior displayed by unidirectional fiber-reinforced polymers. Based on a quantitative morphology analysis of epoxy/glass fibers composites, a four-phase model taking into account the fiber spatial distribution is developed to rigorously express the reinforcement effect of the pol ymer matrix over a wide range of fibers and temperatures. Comparisons with other modelings and experiment illustrate the validity of the pro posed approach. In addition, changes in the viscoelastic behavior of t he epoxy matrix in composite materials resulting from a decrease in th e crosslinking degree of such a kind of polymer are, subsequently, ass essed through such an approach.