Failures at Attachment Holes in Brittle Matrix Laminates

Mechanical attachments for a brittle-matrix fiber-reinforced cross-ply composite are analyzed. Two model problems are considered: first, a bolt-loaded strut, and second, an infinitely-wide plate with evenly-spaced bolts. The possible failure mechanisms for the strut are identified, and the influence of bolt size, bolt location, bolt elasticity, and interfacial friction on these failure mechanisms and the associated failure loads are evaluated. The bolt spacing for the plate is identified that best takes advantage of a SiC/MAS cross-ply's ability to redistribute stresses through the mechanism of matrix cracking. Boundary value problems are solved using the finite element method. The cross-ply's constitutive behavior is described by the model of Genin and Hutchinson [1].