Disappearance of free-edge stress singularity in composite laminates

Based on the anisotropic elasticity theory and Lekhnitskiiʹs complex potential functions, the rλ−1 type stress singularities occurring near the apex of free edge composite laminate are studied. The singularity order depends on wedge angles, which form a half plane, material properties and the fiber orientation. The disappearance conditions of the stress singularity can be found from the contours of λ−1 plotted in a full circular region. Numerical results regarding to zero order singularity are obtained for some α−(180°−α) bonded wedges, such as α=45°, 60°, 75° and 90°. Also, the applications of this approach to angle-ply and cross-ply composite laminates for diminishing the stress singularity near the apex of free edge are discussed.