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Characterization of fatigue damage for bonded composite skin/stringer configurations
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Cvitkovich, Michael Krueger, Ronald Paris, Isabelle |
| Copyright Year | 2008 |
| Description | 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. |
| File Size | 15812758 |
| Page Count | 40 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_20080018713 |
| Archival Resource Key | ark:/13960/t52g2q34b |
| Language | English |
| Publisher Date | 2008-05-08 |
| Access Restriction | Open |
| Subject Keyword | Composite Materials Fatigue Tests Cutting Nondestructive Tests Cracks Fatigue Materials Delaminating Bonded Joints Flanges Optical Microscopes Damage Static Tests Loads Forces Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Technical Report |
