Troisiéme Conférence Européenne sur les Matériaux et les Procédés Avancés
J. Phys. IV France 03 (1993) C7-1601-C7-1606
Prediction of failure probability of large unidirectional fibre reinforced compositesM. LIENKAMP and H.-E. EXNER
Technical University of Darmstadt, Department of Materials Science, Petersenstr. 30, 64287 Darmstadt, Germany
Tensile strength data obtained from measurement of small test specimens cannot be easily extrapolated to large composite structures. A statistical model is proposed which predicts the strength of composites from the properties of their constituents. It is assumed that with increasing load fibres fail at their most severe flaws and overload adjacent fibres and larger clusters of broken fibres develop locally. At a certain size cluster growth gets critical, i.e. the composite fails. The probability of formation of one cluster of the critical size characterises the failure probability of the composite. Three different local load sharing rules are compared. The predicted composite strength is insensitive to the chosen local load sharing rule. A parametric study for different Weibull moduli of the fibres, different sizes and failure probabilities of the composite is conducted. The critical cluster size and the tensile strength of the composite are predicted.
© EDP Sciences 1993