Experimental study on the matrix crack-fiber interaction using photoelasticity method

Abstract

The stress field of the matrix crack perpendicular to fiber bundles was studied by the method of photoelasticity. First, the stress intensity factor at the matrix crack tip in the neighbor of the fiber bundles are derived based on transformation toughening theory and Eshelby equivalent inclusion method. Then, a photoelastic experiment was conducted using a specimen with a fiber bundle in the center as an inclusion, and the typical isochromatic fringe pattern around the crack tip near the fiber bundle was obtained. Finally a numerical simulation was carried out based on the plane stress assumption, and the stress intensity factor measured using photoelasticity was compared with the numerical and theoretical results. These results will play an important role for evaluating the mechanism of crack-fiber interaction in fiber reinforced composites.