INNOVATIVE DESIGN AND PROCESSING OF HIGH TEMPERATURE COMPOSITE FASTENERS

THE NATIONAL AERO-SPACE PLANE AND ADVANCES IN PROPULSION SYSTEMS WILL REQUIRE NEW COMPOSITE MATERIALS WITH IMPROVED PERFORMANCE IN EXTREME HIGH TEMPERATURE ENVIRONMENTS. RECENT EXPERIENCE WITH COMPOSITES IN AIRFRAMES HAS INDICATED THAT STRESS CONCENTRATIONS DUE TO FASTENERS AND CUT-OUTS IS THE LIMITING FACTOR IN MANY COMPOSITE STRUCTURES. U.S. COMPOSITES WILL APPLY INNOVATIVE PROCESSING TECHNOLOGY BASED ON COMPUTER CONTROLLED BRAIDING AND ON-LINE IMPREGNATION TO DEVELOP PROTOTYPE HIGH TEMPERATURE FASTENERS. FIBER PLACEMENT TECHNIQUES WILL BE EVALUATED AND OPTIMIZED WITH FINITE ELEMENT ANALYSIS. A PROTOTYPE FASTENERS WILL BE MADE OF CARBON-CARBON MATERIALS. THE PHASE I RESEARCH WILL INCLUDE AN EVALUATION OF FUTURE EXTENSIONS OF THE TECHNOLOGY TO CERAMIC AND OTHER MATRIX MATERIALS AND MODIFIED IMPREGNANTS WITH IMPROVED OXIDATION PROTECTION.