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] s. 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 [± ϕ 2] 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.