Characterization of Fatigue Damage for Bonded Composite Skin/Stringer Configurations
- Author:
- Paris, Isabelle
- Published:
- May 08, 2008.
- Physical Description:
- 1 electronic document
- Additional Creators:
- Krueger, Ronald and Cvitkovich, Michael
- Access Online:
- hdl.handle.net
- Restrictions on Access:
- Unclassified, Unlimited, Publicly available.
- Summary:
- The fatigue damage was characterized in specimens which consisted of a tapered composite flange bonded onto a composite skin. Quasi-static tension tests were performed first to determine the failure load. Subsequently, tension fatigue tests were performed at 40%, 50%, 60% and 70% of the failure load to evaluate the debonding mechanisms. For four specimens, the cycling loading was stopped at intervals. Photographs of the polished specimen edges were taken under a light microscope to document the damage. At two diagonally opposite corners of the flange, a delamination appeared to initiate at the flange tip from a matrix crack in the top 45deg skin ply and propagated at the top 45deg/-45deg skin ply interface. At the other two diagonally opposite corners, a delamination running in the bondline initiated from a matrix crack in the adhesive pocket. In addition, two specimens were cut longitudinally into several sections. Micrographs revealed a more complex pattern inside the specimen where the two delamination patterns observed at the edges are present simultaneously across most of the width of the specimen. The observations suggest that a more sophisticated nondestructive evaluation technique is required to capture the complex damage pattern of matrix cracking and multi-level delaminations.
- Collection:
- NASA Technical Reports Server (NTRS) Collection.
- Note:
- Document ID: 20080018713., L-19468., and NASA/TM-2008-215308.
- Terms of Use and Reproduction:
- Copyright, Distribution under U.S. Government purpose rights.
- Access Online:
- hdl.handle.net
View MARC record | catkey: 15999788