The 3D Stress Field at the Edge of a Circular Hole and the Interface of a Laminated Composite Plate

Abstract

The author in this paper investigates the 3D stress field in the immediate vicinity of a bonded interface and the free edge of a hole in a laminated composite plate The laminates are assumed to be of homogeneous and isotropic materials, but of different elastic properties As to loading, a uniform tensile load is applied in the plane of the plate and at points far remote from the hole (see Figure 1)In constructing the local asymptotic solution, the author assumes the 3D field in a cer tain form which then permits a straightforward Williams approach for the determination of the stress singularities. The displacement and stress fields are recovered explicitly and a stress singularity is shown to exist for certain shear moduli ratios of G2/ G1. In general, the stress singularity is shown to be a function of the respective ratios of the shear moduli and Poisson's Moreover, the presence of a second singularity is observed which has sig nificant implications to the problem of adhesion An extension of the results to anisotropic layers is also discussed.