Open hole and postimpact compressive fatigue of stitched and unstitched carbon-epoxy compositesThe performance is studied of a stitched uniweave fabric composite and that of a toughened tape composite. The effects of stitching on compression fatigue life are addressed. Post impact compression fatigue and open hole fatigue tests were run on an AS4/3501-6 uniweave with stitching and a toughened IM7/8551-7 tape without stitching. Stitching was found to increase the thickness and consequently the weight of the composite material. The two materials were compared on an equal carbon content basis as well as on an equal weight basis. The excess thickness in the stitched uniweave composite was responsible for the lower fatigue life, on an equal carbon basis, compared to the toughened resin tape composite. Comparison of fatigue lives on an equal carbon content basis indicated that puncture or crimp type damage from stitching has very little effect on compression failure. Post impact fatigue test showed that although the damage area in the stitched uniweave composite was twice that of the toughened tape composite, the fatigue lives of the stitched composite were significantly longer than those of the toughened composite. Thus, it appears that the increase in thickness from stitching is much more of a penalty than crimped fibers or puncture type damage from stitching.
Document ID
19920061980
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Portanova, Marc A. (Lockheed Engineering and Sciences Co. Hampton, VA, United States)
Poe, Clarence C. (NASA Langley Research Center Hampton, VA, United States)
Whitcomb, John D. (NASA Langley Research Center Hampton, VA, United States)
Date Acquired
August 15, 2013
Publication Date
January 1, 1992
Subject Category
Composite Materials
Meeting Information
Meeting: Conference on Composite Materials: Testing and Design