Notched response of non-crimp fabric thin-ply laminates: Analysis methods

Analysis methods to predict the open-hole tensile and compressive response of thin-ply non-crimp fabric laminates are investigated in this paper. The point- and average-stress models and the Finite Fracture Mechanics model are used. It is shown that all models predict with reasonable accuracy the observed size effects in both tension and compression. The Finite Fracture Mechanics model, which requires two material properties (the unnotched strength and the fracture toughness) and does not need calibration from a baseline specimen, is used to predict the notched response of thin-ply non-crimp fabric laminates and of typical aerospace grade laminates based on unidirectional pre-impregnated plies. No substantial differences in notch sensitivity and inherent material/geometry brittleness is predicted.