Author: National Aeronautics and Space Adm Nasa

Publisher: Independently Published

Published: 2018-10-11

Total Pages: 34

ISBN-13: 9781728694351

The residual tensile strength of a thick graphite/epoxy composite with impact damage was predicted using surface crack analysis. The damage was localized to a region directly beneath the impact site and extended only part way through the laminate. The damaged region contained broken fibers, and the locus of breaks in each layer resembled a crack perpendicular to the direction of the fibers. In some cases, the impacts broke fibers without making a visible crater. The impact damage was represented as a semi-elliptical surface crack with length and depth equal to that of the impact damage. The maximum length and depth of the damage were predicted with a stress analysis and a maximum shear stress criterion. The predictions and measurements of strength were in good agreement. Poe, C. C., Jr. and Harris, C. E. and Morris, D. H. Langley Research Center RTOP 506-43-11-04