Buckling of bridging fibres in composites

In brittle materials uch as concrete and ceramics, fibre reinforcement has been widely accepted as an effective way of improving their strength and tough-ness. In addition, a notable pseudo strain-hardening phenomenon can contribute to a significantly en-hanced ductility of the composite when an ade-quately designed fibre system is used. This condition was first proposed by Aveston et al. [1], and later extended by Marshall et al. [2] for continuous aligned fibre reinforced brittle matrix composites. More recently, further extensions to randomly ori-ented discontinuous fibre reinforced composites have been presented [3, 4]. Upon satisfying the conditions described in the above mentioned micro-mechanical models, the ultimate t nsile strains o