Stresses in fibre-reinforced materials

A relatively detailed knowledge of the stress distribution around the fibres in a composite material is required in order to predict the mode of failure. Idealized models of a reinforced material, consisting of an isolated fibre embedded in a brittle matrix, have been analysed by the photoelastic technique. Complete stress distributions have been obtained in the vicinity of both square- and semicircular-ended fibres with the composite subjected to uniaxial tension. It is interesting to find that the maximum tensile and shear stresses induced at the tip of the semicircular fibre are significantly greater than the corresponding values for the square-ended fibre. This apparent anomaly is explained by the mechanism controlling the load transfer from the matrix to the fibre.