Volume fraction effects on interfacial adhesion strength of glass-fiber-reinforced polymer composites

The performance of fiber-reinforced composites is often controlled by the p roperties of the fiber-matrix interface. Good interfacial bonding (or adhes ion), to ensure load transfer from matrix to reinforcement, is a primary re quirement for effective use of reinforcement properties. Thus, a fundamenta l understanding of interfacial properties and a quantitative characterizati on of interfacial adhesion strength can help in evaluating the mechanical b ehavior and capabilities of composite materials. A large number of analytic al techniques have been developed for understanding interfacial adhesion of glass-fiber-reinforced polymers. Among these techniques, the vibration dam ping technique has the advantage of being non-destructive as well as highly sensitive for evaluating the interfacial region, and it can allow the mate rials industry to rapidly determine the mechanical properties of composites . In the present study, a simple optical system was contributed for measuri ng the damping factor of uniaxial fiber-reinforced polymer composites in th e shape of cantilever beams. The interfacial damping factors in glass-fiber -reinforced epoxy resin composites were correlated with transverse tensile strength, which is a qualitative measurement of adhesion at the fiber-matri x interface. Four different composite systems were tested in this study. In each system, three different surface treatments of glass-fiber at three di fferent volume fractions were evaluated. The experimental results show an i nverse relationship between damping contributed by the interface and compos ite transverse tensile strength. (C) 2000 Elsevier Science S.A. All rights reserved.