Accession Number : ADA301864

Title :   Increased Fracture Toughness of Graphite-Epoxy Composites Through Intermittent Interlaminar Bonding.

Descriptive Note : Final technical rept. Nov 78-Oct 79,

Corporate Author : MICHIGAN UNIV ANN ARBOR

Personal Author(s) : Felbeck, David K. ; Jea, Li-Chung

PDF Url : ADA301864

Report Date : OCT 1979

Pagination or Media Count : 39

Abstract : The objective of this study has been to increase the fracture toughness of multi-layer continuous-filament graphite-epoxy composites. The method used is intermittent interlaminar bonding, which can lead to a large increase in the fracture surface area. In this study we achieved intermittent bonding through introduction of thin perforated Mylar between the layers of the composite. For the best optimum condition included in this study, fracture toughness was increased from about 100 kJ/sq m for untreated specimens to an average of about 500 kJ/sq m, while tensile strength dropped from 500 MPa to 400 MPa, and elastic modulus remained the same at about 75 GPa. An approximate analysis is presented to explain the observed improvement in toughness. (MM)

Descriptors :   *TOUGHNESS, *FRACTURE(MECHANICS), *GRAPHITE EPOXY COMPOSITES, TENSILE STRENGTH, OPTIMIZATION, COMPOSITE MATERIALS, LAMINATES, FIBER REINFORCED COMPOSITES, MODULUS OF ELASTICITY, CARBON FIBERS, HIGH STRENGTH, BONDING, FILAMENTS, THINNESS, FAILURE(MECHANICS), EPOXY RESINS, DELAMINATION, AXIAL LOADS, PERFORATION.

Subject Categories : Laminates and Composite Materials

Distribution Statement : APPROVED FOR PUBLIC RELEASE