Effects of material and stacking sequence on behavior of composite plates with holes

The Effect of Ply Lay-Up Sequence on the Fracture Toughness of Boron Aluminum

“…The segregation of 0° and 90° plys caused a 20% increase in fracture toughness over the alternating ply lay-up sequence. This is quite different from a previously noted dependence of composite strength on lay-up sequence [6,7] , in that the unnotched composite tensile performance for the present study was totally unaffected by this change in sequence. The prior work, on resin matrix composites, was explained in terms of the generation of high interlaminar stresses due to the differences in Poisson's ratio between the various plys.…”

The Compressive Failure of Graphite/Epoxy Plates with Circular Holes

“…Having characterized the basic behavior, Rowlands, Daniel and Whiteside [17], and Daniel, Rowlands and Whiteside [18], described the effect of geometry and loading, and material and stacking sequence respectively, on laminates with cutouts. The results indicate that failure occurred off the axis perpendicular to load application where interlaminar shear and normal stress are maximum and where circumferential normal and shear strain increase nonlinearly with increased load.…”

“…Near the hole boundary, the matrix is well above its failure strain, 0.0036 cm/cm, and the circumferential strain is well above the analytical buckling strain of a plate without a hole. The ability of the composite to support such high strains locally is due to the nonuniform strain gradient decaying radially away from 'the hole that confines the high strains to a small volume of material [18].…”

Dual magnification digital image correlation based strain measurement in CFRP Laminates with open hole☆

“…Strain gage, moiré and birefringent coating were synthetically utilized in the work of Rowlands et al [1,2]. Mollenhauer et al used moiré interferometry to investigate the interlaminar deformation along the cylindrical surface of a hole in composite laminates plate [3].…”