Dynamic Transverse Debonding of a Single Fiber

Abstract

By integrating a Kolsky tension bar along with a high-speed x-ray phase contrast imaging method and a high speed optical camera, high strain rate debonding processes of an opaque composite composed of a single S-2 fiber and SC-15 epoxy resin is recorded in real time and analyzed. Specifically, imaging of transverse debonding initiation and progression along with debonding loads are obtained and then compared to quasi-static debonding loads in this research. The dynamic loading direction was perpendicular to the fiber axial direction. The dynamic tensile loading history as the debonding initiated and propagated was recorded using a piezoelectric load cell. The initial debonding crack speed was also measured. Quasi-static experiments were also completed as a basis of comparison. It is shown that the debonding loads under dynamic and quasi-static loading conditions are similar. The fracture surfaces from the dynamically debonded samples were subsequently examined by scanning electron microscopy.