Probabilistic Study of Visible Length of Fibers under the Surface of a Short Fiber Reinforced Composite

The so-called 'visible length' under the surface of a short fiber reinforced composite was examined, assuming that fibers under the composite surface could be observed. The fibers under the surface are overlapped by other fibers. The length of the part between other overlapping fibers is the visible length. Relative position of the fiber in the composite can be classified into six categories when the fiber was observed from the composite surface. In each category, projection length of the fiber to the composite surface was calculated. The result was substituted for the method proposed before and the visible length distribution was obtained. It was found that the average visible length in the composite dose not significantly changes, if the average fiber length exceeds 30 times of the fiber diameter. Furthermore the influence of fiber volume fraction on the visible length was clarified.