BOUNDARY-LAYER EFFECTS OF INTERLAMINAR STRESSES ADJACENT TO A HOLE IN A LAMINATED COMPOSITE PLATE

An eigenfunction expansion is developed for the determination of the three-dimensional stress field in the neighborhood of the intersection of the free edge of a hole and an interface in a laminated composite plate. For transversely isotropic laminae, the stress field is shown to possess a weak singularity whose strength depends on the material constants, the fiber orientations of the two adjacent laminae as well as the polar angle theta. Results for [0-degrees/90-degrees], [0-degrees/70-degrees], [0-degrees/45-degrees], and [0-degrees/20-degrees] are presented and the best and worst fiber orientations are identified. Finally, the interlaminar stresses are computed and the variation as a function of the angle theta is identified. The circumferential stress sigma-theta-theta is shown to possess a small jump across the interface. Results for its behavior in the interior of each layer are also given.