In this study, an equation for predicting width distribution of overlapping part of fibers observed under the surface of a short fiber reinforced composite in which fibers were random in 2D was formulated. It was assumed that the fiber direction distribution was random in a plane parallel to the composite surface. The overlapping width of one fiber was approximated to a rectangle with constant width w. The rectangles could be arbitrarly located between two edges of the fiber. Number of the rectangles located on the fiber could be expressed as a linear function of depth from the composite surface. When the width of overlapping part was between (n-1)w and nw (n= 1, 2, 3,…), the width distribution of the overlapping part were given by n-2 following equation of the width of the overlapping part. The distribution of width distribution of overlapping part of fibers could be expressed by an extremely simple equation.
