Simplified three-dimensional analysis and design of fibre reinforced annular discs surrounding a circular hole in a flat plate under various loading conditions

Abstract

A flat plate containing a circular hole is subjected to arbitrary bi-axial stresses at infinity; adajcent to the hole and bonded symmetrically to both sides of the plate are cylindrically wound fibre composite annular discs. The relatively low shear moduli of the composite cause shear lag effects normal to the plane of the plate. The present paper shows that it is possible to allow for these effects, within the framework of a two-dimensional analysis, by the use of an effective thickness for the reinforcement which is a function of the overall geometry, the elastic moduli and the type of loading. The practically important case of applied uniaxial stress is considered in detail and it is shown how, for a given weight of reinforcement, the reinforcement cross-section can be chosen to minimise the peak stresses.