ON THE HYBRID EFFECT AND MATRIX YIELDING AT FIBRE BREAKS IN HYBRID COMPOSITE SHEETS

Abstract

SUMMARY The post matrix yield problem is formulated for a finite width hybrid composite sheet, which contains an alternating arrangement of high modulus (HM) and low modulus (LM) fibres. A hybrid parameter, R, which is the ratio of the axial stiffness of the LM fibres to that of the HM fibres, is shown to have an important effect on the fibre stress concentration, and the extent of yield zone near fibre breaks. A hybrid effect, where the HM fibres can sustain higher loading and elongation than when they exist alone in a non-hybrid composite, has been noted in the literature, and is given additional corroboration by the present results, which evaluate the effect of matrix yielding near both internal and edge fibre breaks. An eigenvector expansion approach is used to solve the system of equations.