Impact damage of a graphite/PEEK
Low-velocity non-penetrating impact has been applied to graphite polyetheretherketone (AS4/APC-2) laminates in accordance with the USAF guidelines for designing damage tolerant primary structures. The extent of delaminations and dent depths for two lay ups and five thicknesses at room temperature and ambient moisture conditions have been determined. Based on these findings as well as those presented elsewhere it may be concluded that the ``softer`` lay up (40/50/10), up to about 75-ply thickness, is more damage tolerant than the ``harder`` lay up (60/30/10) because within this thickness range the ``softer`` lay up displays smaller dent depths, smaller delaminated areas and higher post-impost compressive strength (PICS). For laminates thicker than 75 plies, the relative situation in delamination extent and PICS is reversed, i.e. the ``harder`` lay up is more damage tolerant than the ``softer`` one. The test data obtained in this experimental investigation provide the amount of initial damage to be assumed for a damage tolerant design of USAF primary structures made out of AS4/APC-2 graphite/PEEK. In addition, 9 these data may serve to validate the predictive capability of appropriate analytic models.
- OSTI ID:
- 89905
- Report Number(s):
- CONF-9409291--; ISBN 1-56676-220-0
- Country of Publication:
- United States
- Language:
- English
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