Quick Reaction Evaluation of Materials and Processes. Delivery Order 0010: Bonded Boron Patch Repair Evaluation
Abstract
The C-141 weep-hole repair, performed in the early 1990s, was the first widespread application of a bonded boron composite repair on a critical structure. This program involved the evaluation of the residual strength and integrity of the bonded boron repairs from aircraft that were decommissioned and to be scrapped. A total of 67 residual strength tests were performed, including 54 original bonded boron composite repaired specimens, 4 new bonded repair specimens, and 9 baseline residual strength specimens. The test specimens consisted of the bonded repair with a substantial amount of the surrounding lower wing structure to allow the specimen to be gripped for testing. A novel Stereo-Optic non-contact surface strain field mapping system was used to characterize the patch/specimen load interaction, strain concentrations at the patch tips, as well as patch delamination events at high stresses. The results of the project indicate that the bonded boron repair provided significant residual strength after 10 years of accumulated flight time. There appears to be little difference in residual strength of the original repairs as compared to new bonded repairs utilizing the same materials and methods. Of the 54 original repairs tested, a total of nine repairs exhibited some degree of patch failure during the tests, all of which occurred at relatively high stresses.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 2006
- Accession Number
- ADA472214
Entities
People
- Nick J. Jacobs
Organizations
- University of Dayton