SEDL / STP / STP664-EB / STP35808S

Erosion Damage in Carbon-Carbon Composites at Hypersonic Impact Velocities

Adler, WF
Director, Effects Technology, Inc., Santa Barbara, Calif.

Evans, AG
Professor, University of California at Berkeley,

Pages: 31    Published: Jan 1979

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Abstract

The damage to three-dimensional orthogonal carbon-carbon composites created by particle impacts ranging from 1800 to 6000 ms^-1 has been characterized for three weave constructions at both ambient and temperatures up to 3600¼C. The subsurface damage modes in the vicinity of the impact crater are described for the range of conditions investigated. Hypotheses are advanced concerning the failure modes and kinetics for the material ejected from the crater based on examination of sectioned specimens and high-speed photographic sequences.

Kinking of the longitudinal and lateral fiber bundles is found to be the primary damage mode. Kinking of the longitudinal fiber bundles under the impact site (which controls the depth of the impact crater) displays a relatively minor dependence on the bundle dimensions. The lateral extent of the impact crater is dependent on the longitudinal fiber bundle content—decreasing as the bundle dimensions increase. It is hypothesized that kinking of the longitudinal fibers leads to this removal, which is related to kinking of the adjacent lateral fiber bundles which increases with the particle impact velocity.