DAMAGE DEVELOPMENT IN STEEL FIBRE COMPOSITES WITH UNIDIRECTIONAL AND QUASI-UNIDIRECTIONAL WOVEN ARCHITECTURES

The effect of the microstructure on the tensile properties and facture behaviour of steel fiber composites is investigated. Two types of composites are produced: with quasi-unidirectional woven and perfectly unidirectional fibre architectures. The main difference in the two microstructures is the fibre distribution. In the quasi-UD composite, steel fibres are tightly packed in bundles with 85% of the local fibre volume fraction and these bundles are separated by resin rich areas. In the perfect-UD composite, steel fibers are homogeneously distributed throughout the composite with an average volume fraction of 50%. The quasi-UD composites with highly packed fibres are found to have a higher strain to failure. Acoustic emission registration was used to better understand the difference in fracture behaviour of these materials, affected by their microstructures.