INVESTIGATION OF FIBER-REINFORCED THERMOPLASTIC MATERIALS FOR USE IN ENERGY-ABSORBING SUBFLOOR STRUCTURES

THE MISSION AND PERFORMANCE REQUIREMENTS OF U.S. ARMY AIRCRAFT ARE CONTINUALLY BECOMING MORE STRINGENT. TO MEET THESE MMORE DEMANDING REQUIREMENTS, SIGNIFICANT WEIGHT REDUCTIONS MUST BE MADE. THE USE OF COMPOSITE MATERIALS IN PRIMARY AIRCRAFT STRUCTURES IS ONE OF THE TECHNOLOGIES BEING DEVELOPED TO HELP MEET THESE GOALS. WHILE THE TECHNOLOGY TO INCORPORATE ADVANCED COMPOSITES INTO PRIMARY AIRCRAFT STRUCTURES IS BEING DEVELOPED, THE FULL POTENTIAL OF THESE MATERIALS IS NOT BEING REALIZED WITH THE CURRENTLY AVAILABLE THERMOSETTING MATRIX RESINS DUE TO THEIR LACK OF DAMAGE TOLERANCE AND DUCTILITY. THE PROPOSED PROGRAM IS DIRECTED AT IMPLEMENTING THERMOPLASTIC MATRIX COMPOSITES IN ENERGY-ABSORBING HELICOPTER SUBFLOOR STRUCTURAL COMPONENTS. THE SUCCESSFUL COMPLETION OF THIS PROGRAM WILL YIELD THE SELECTION OF THERMOPLASTIC COMPOSITE MATERIALS THAT CAN BE IMPLEMENTEDINTO DIFFERENT KEEL BEAM DESIGN CONCEPTS WHICH PROVIDE EFFECTIVE ENERGY ABSORPTION CAPABILITY UNDER CRASH LOADS WHILE STILL MAINTAINING POST-CRUSH INTEGRITY. THIS SELECTION WILL BE MADE BY EXAMINING EXISTING TECHNOLOGY, SCREENING CANDIDATE THERMOPLASTIC COMPOSITE MATERIALS, AND CONCEPTUAL DESIGN OF ENERGY-ABSORBING KEEL BEAM STRUCTURES. CONSIDERATION WILL BE GIVEN TO PERFORMANCE, PRODUCIBILITY, COST, AND WEIGHT.