BOUNDARY-LAYERS IN WEDGES OF LAMINATED COMPOSITE STRIPS UNDER GENERALIZED PLANE DEFORMATION .1. ASYMPTOTIC SOLUTIONS

Abstract

Based upon Lekhnitskii's formulation and the Stroh formalism, the structure of the asymptotic solutions has been examined for the boundary layer on the wedge type cross section of a laminated composite strip. The composite strip is assumed under the so-called generalized plane deformation, which includes tension, bending and/or torsion by the terminal tractions as well as the generalized plane strain problem. The solution structures are obtained, with the aid of numerical calculation, for various kinds of wedge geometry including the free edge and the delamination cracks with the crack faces opened or closed. Finally the nature of the asymptotic solutions is discussed, including the mode mixity of singular stress field ahead of the wedge tip, it is found that for a free edge problem the mode mixity of the singular asymptotic traction vector on the interfacial plane near the free edge remains invariant under varying types of remote loadings once a pair of adjacent materials (or ply orientations) is given and that accordingly one single scaling parameter governs the near field response.