Investigation of Brittle Fractures in Graphite-Epoxy Composites Subjected to Impact
Final rept. 7 Nov 1973-20 Dec 1974
MCDONNELL DOUGLAS ASTRONAUTICS CO HUNTINGTON BEACH CA
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The principal objectives of this program were 1 to establish how the brittle fracture characteristics of graphite-epoxy composites subjected to impact are influenced by such parameters as fiber and matrix properties, fiber orientation, stacking sequence, laminate thickness, curvature effects and interleaving effects and 2 to recommend solutions to the brittle fracture problem. To accomplish these objectives, a three-phase program was conducted. Phase I involved a literature survey on the experimental and theoretical work on the brittle fracture of composites subjected to impact as well as a literature survey on failure theories for brittle, orthotropic, and anisotropic materials. In Phase II, available computer solutions such as SAAS III, ASAAS and CYLINDER were modified andor extended to the problems. In Phase III the test plan was implemented, which involved fabrication and impact testing of specimens. Types of graphite fibers used in the experimental program included Thornel 300, Modmor II and Celion GY-70. Types of resins investigated included 5208 epoxy, ERLA 4617 and polysulfone.
- Laminates and Composite Materials