Mixed-mode fracture of notched unidirectional and off-axis laminates under tensile loading

ABSTRACT: The mixed-mode fracture of matrix dominated composite laminates con-taining central holes and cracks was studied using some graphite/epoxy off-axis AS4/3502 balanced symmetric laminates, [±ϕ2]. The uniaxial failure of a 0° laminate, which is the main load carrier of multidirectional laminates, was also investigated. Interesting results were observed for the [± ϕ2]s laminates with a central normal crack. In this paper, the terms "notch sensitivity " and the "notched shape sensitivity " are distinguished, defined and classified with examples. Anisotropic finite width correction factors were applied to inter-polate the experimental data. In general, the predicted notched strength and the failure initiation locations correlate reasonably well with the experimental results. 1