Influence of relative ply orientations on the nature of the edge effect singularities for a circular hole in a composite laminate

• Published in: International journal of solids and structures 1989, Vol.25 (10), p.1115-1132
• Main Authors: Shalev, Doron, Reifsnider, K.L.
• Format: Article
• Language: English
• Subjects: Exact sciences and technology; Fracture mechanics (crack, fatigue, damage...); Fundamental areas of phenomenology (including applications); Physics; Solid mechanics; Structural and continuum mechanics
• ISSN: 0020-7683; 1879-2146
• DOI: 10.1016/0020-7683(89)90071-1

A method is developed for the analysis of the nature of the singularities at the free edge of an elliptical hole in a composite laminate. The method is general enough to be applicable to any type of laminate with or without a hole. Boundary layer theory, as originated in aerodynamics is used to simplify the equations applied within the boundary layer region, while compatibility is achieved at the other border of that region to comply with anisotropic plate theory. In the present case the method is applied to investigate the effect of the free edge of a hole on stresses at the ply interface within the boundary layer. The immediate application within that region is the solution for the Energy Release Rate which is essential to the evaluation of critical conditions such as delamination initiation. Attention is focused on the influence of adjacent ply orientations on the order of singularity at the interface.