Crack Arrest by Strong Short Fibers in a Brittle Composite

Abstract

Using the mechanics of inclusions, the effect of strong fibers on the arrest of a mode 1 crack in a brittle material has been studied. Two effects of fibers on the crack arrest are considered; bridging action and sliding. The fibers bridge the crack and the bridging action reduces the energy release rate during the crack extension. The sliding of the fibers results in an effective increase in the fracture toughness, since the sliding under non-vanishing friction on matrix-fiber interfaces dissipates energy. The reduction in the energy release rate and the increase in the fracture toughness are given in analytical forms which involve the size of a crack, the geometry and distribution of fibers and external and frictional stresses. Diagrams to indicate the stability and growth of a crack reinforced by fibers are presented.