TENSILE FRACTURE BEHAVIOUR OF THE REINFORCING YARNS IN BRITTLE MATRIX COMPOSITES

摘要

Using experimentally determined data on the fibre radius distributions, yarn geometry, matrix and fibre elastic moduli and frictional shear stress at the matrix/fibre interface, the failure probability of the composite fibre yarns is estimated. Each fibre is divided into a fixed number of segments above and below the matrix crack. The failure probability on every segment of each fibre is computed using Weibull fibre strength statistics. A fibre is assumed to be broken when the cumulative failure probability for the complete yarn reaches a value of 0.5. After fibre failure, the broken fibre can only carry the frictional load and the load drop is transferred to its neighbours according to their distances to the broken fibre.