Accession Number : AD0776051

Title :   An Experimental Investigation of the Stress Levels at Which Significant Damage Occurs in Graphite Fiber Plastic Composites.

Descriptive Note : Final technical rept. Feb 70-31 Dec 71,

Corporate Author : SOUTHWEST RESEARCH INST SAN ANTONIO TEX

Personal Author(s) : Grimes,Glenn C. ; Francis,Philip H. ; Commerford,George E. ; Wolfe,George K.

Report Date : MAY 1972

Pagination or Media Count : 257

Abstract : Significant damage stress levels in HTS/ERLA-2256 graphite epoxy composites were investigated. In order to do this it was necessary to establish high quality fabrication and inspection techniques for processing flat laminates and tubes and to experimentally characterize the mechanical and physical properties of the composite (lamina and laminate). Two significant damage stress levels were observed in laminates and related to the material's mechanical behavior. Empirically modified micro/macro-mechanics techniques and maximum strain theory were used to predict these stress levels as well as other composite properties with reasonable accuracy. These predicted values are used in normalizing the experimental data to one fiber and void volume for direct comparison and statistical analysis. Material design allowables and confidence limits on the composite properties were established and possible application criteria proposed. (Author, modified-PL)

Descriptors :   *FIBER REINFORCED COMPOSITES, *GRAPHITE, EPOXY RESINS, LAMINATES, FABRICATION, TUBES, PANELS, TENSILE PROPERTIES, COMPRESSIVE PROPERTIES, STRESSES, STRAIN(MECHANICS), TEST, STANDS

Subject Categories : Laminates and Composite Materials

Distribution Statement : APPROVED FOR PUBLIC RELEASE