Interlaminar stresses at the free corners of a laminate

The generation of localized high interlaminar stresses is a well-known phenomenon along the free edges of composite laminates ("free-edge effect"). In a similar way a corresponding interlaminar stress localization occurs at the free corners of a laminate ("freecorner effect"). The subject of the present contribution is a closed-form analytical approach to the stress field in the vicinity of a free rectangular corner of a laminate with symmetrical lay-up under thermal loading. The derived solution is applied to the cases of a carbon fibre reinforced plastics (CFRP) cross-ply laminate and a Ni/AI-laminate. The predicted interlaminar stress distributions at the ply interfaces are shown to be in good agreement with comparative 3-dimensional finite element analyses performed by means of MSC/NASTRAN. © 1999 Elsevier Science Ltd. All rights reserved.