Development of a Graphite Horizontal Stabilizer.
Final rept. 3 Nov 69-31 Aug 75,
DOUGLAS AIRCRAFT CO LONG BEACH CALIF
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A summary of the design synthesis, structural development testing, tooling, manufacturing, and ground testing of an advanced composite horizontal stabilizer for the A-4 Skyhawk is presented. The stabilizer utilized Narmco 5206 graphite-epoxy as the primary load-bearing structural material 58.5 percent by weight. The most significant problem encountered was the development of structurally efficient joints. In ground tests, the graphite stabilizer successfully sustained design ultimate loads and subsequently sustained two lifetimes of fatigue spectrum loads. A positive margin-of-safety of 12 percent was indicated in a final ultimate-strength test after completion of the fatigue test. A flutter analysis based on the natural modes and frequencies of the graphite stabilizer indicated an improvement in empennage flutter speed. A weight reduction of 26.2 percent was achieved in comparison to the existing metal stabilizer.
- Attack and Fighter Aircraft
- Laminates and Composite Materials