Impact tolerance of laminated and 3-dimensionally reinforced graphite-epoxy panels

Conference · Fri Dec 31 04:00:00 EST 1993

OSTI ID:143594

Voss, S; Fahmy, A; West, H ^[1]

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1. North Carolina State Univ., Raleigh (United States). Materials Science and Engineering Dept.

Carbon fiber-reinforced epoxy cross-ply laminates and three-dimensionally woven preform-reinforced panels were prepared and tested for their impact tolerance. The composites were impacted with small (4.3 mm diameter) blunt steel cylinders, fired from an air-gun with impact energies ranging from 2 J to 26 J. The resulting damage was observed visually, by optical microscopy, and by thermally decomposing the matrix in an oven at 400 C. A four-point flexure test was used to measure the flexural modulus as well as the initial and final flexure strength of the virgin and impacted materials. The flexure modulus was found to be less sensitive to impact damage than the flexural strength which suffered significant reductions at energies below the barely visible impact damage (BVID) for both materials. The three-dimensionally woven material though, was found to be significantly more impact resistant than the laminated material. The four-point flexure test was found to be a useful test, simple to perform, and yet sensitive and reliable.

• OSTI ID: 143594
• Report Number(s): CONF-930246--; ISBN 0-87339-251-5
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COMPOSITE MATERIALS
FLEXURAL STRENGTH
GRAPHITE
IMPACT STRENGTH
MECHANICAL PROPERTIES
MICROSTRUCTURE
TENSILE PROPERTIES