Review of methods for characterization of interfacial fiber‐matrix interactions

Abstract This paper reviews various common methods for studying fiber‐matrix interaction with specific evaluation of the critical fiber length method. Commonly accepted methods are often shown to be unsatisfactory because interfacial results may not be independent of fiber tensile strength properties. A new concept for measuring fiber‐matrix interaction in a single filament, or in a single uniaxially reinforced thin layer, sandwiched between two relatively thick unreinforced layers is proposed. This method relies upon variable curvature bending jigs introducing continuously changing longitudinal shear profiles across the fiber surface by clamping the sandwiched specimen onto the jig surface and also upon the availability of physical detection methods of debonding fronts.