Accession Number : ADA012269


Title :   Investigation of Brittle Fractures in Graphite-Epoxy Composites Subjected to Impact


Descriptive Note : Final rept. 7 Nov 1973-20 Dec 1974


Corporate Author : MCDONNELL DOUGLAS ASTRONAUTICS CO HUNTINGTON BEACH CA


Personal Author(s) : Greszczuk, L B ; Chao, H


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a012269.pdf


Report Date : May 1975


Pagination or Media Count : 217


Abstract : 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 and/or 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.


Descriptors :   *IMPACT TESTS , *FRACTURE(MECHANICS) , *REINFORCED PLASTICS , STRESSES , FIBERGLASS , ALIGNMENT , COMPUTER APPLICATIONS , EPOXY RESINS , BRITTLENESS , CARBON FIBERS , GRAPHITE , AIRCRAFT


Subject Categories : Aircraft
      Laminates and Composite Materials


Distribution Statement : APPROVED FOR PUBLIC RELEASE