Effects of interfacial damage on the global and local static response of cross-ply laminates

The problem of the implications of interfacial damage on the local and global static response of cross-ply laminated flat structures is addressed in this paper. As a basic prerequisite, a third-order generalized zig-zag nonlinear plate theory incorporating the effect of interfacial damage is used. The theory rests upon a representation of the displacement field which: (i) fulfills a priori the shear traction continuity conditions at each interface of the laminate and the free shear traction conditions on the top and bottom external planes of the plate, (ii) satisfies the requirement of continuous displacements at the perfectly bonded interfaces, and (iii) incorporates the interfacial tangential displacement jump condition when slip-type interlayer imperfections are present. The theory also incorporates the geometrical nonlinearities and the thermal effects. Numerical results highlighting the effect of interfacial damage on the static response of laminated composite plates in cylindrical bending are displayed and conclusions on their implications upon their load-carrying capacity are outlined.