## Abstract

A statistical model is proposed which predicts the strength distribution of composites. It accounts for the following parameters: fibre strength distribution, fibre spatial distribution, fibre-matrix interface properties, matrix plasticity, load transfer at broken fibres and load profile of the specimen (bending or tension). The model is solved via Monte Carlo simulation for small specimens and via an analytical approach for large parts. Both techniques predict well the strength distribution of the composite. Aluminium matrix composites reinforced with unidirectional ceramic fibres show a large scatter in three point bending strength. This scatter is caused by the probability that a cluster of broken fibres of a critical size occurs at a given stress level. When the limiting stress is reached the critical cluster grows in an unstable way leading to catastrophic failure of the specimen. The results obtained by this model agree favourably with the experimental findings and indicate that strength prediction using other concepts, like fracture mechanics, global load sharing, a simple rule of mixtures or Weibull statistics, is unreliable for predicting the strength of large composites.

Original language | English |
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Pages (from-to) | 4433-4446 |

Number of pages | 14 |

Journal | Acta Materialia |

Volume | 44 |

Issue number | 11 |

DOIs | |

State | Published - Nov 1996 |

Externally published | Yes |