IMPROVED COMPOSITE FLYWHEEL STORAGE DEVICES FOR ELECTROMAGNETIC LAUNCHERS

ORGANIC FIBERS, SUCH AS POLYETHYLENE, ARE EXTREMELY ATTRACTIVE FOR ROTATING MACHINERY, ENERGY STORAGE DEVICES BECAUSE OF HIGH SPECIFIC LONGITUDINAL STRENGTH AND STIFFNESS PROPERTIES. THE MAJOR LIMITATION IN THESE TYPES OF APPLICATIONS (E.G., FLYWHEELS) IS THE LOW TRANSVERSE TENSILE STRENGTH OF THE COMPOSITE, A CONSEQUENCE OF THE EXTREMELY LOW INTERFACIAL ADHESIVE STRENGTH BETWEEN THE ORGANIC FIBER AND THE RESIN MATRIX. THIS RESULTS IN DELAMINATION AND FRAYING, NEGATING THE USEFUL CHARACTERISTICS OF THIS COMPOSITE. A SURFACE CHEMICAL MODIFICATION PROCESS HAS BEEN DEVELOPED FOR ORGANIC FIBERS WHICH RESULTS IN COVALENT BONDING BETWEEN THE FIBER AND EPOXY RESINS. SIGNIFICANT INCREASES IN INTERFACIAL ADHESION RESULT. TRANSVERSE TENSIL STRENGTHS APPROACHING 4000 PSI HAVE ALREADY BEEN ACHIEVED IN KEVLAR 49/EPOXY LAMINATES. THIS INCREASE IN TRANSVERSE STRENGTH PROPERTIES IS DIRECTLY TRANSLATABLE INTO INCREASED ENERGY STORAGE CAPABILITY. THE SURFACE CHEMICAL MODIFICATION PROCESS WILL BE APPLIED TOPOLYETHYLENE FIBERS FOR FABRICATION INTO UNIDIRECTIONAL EPOXY COMPOSITES. TRANSVERSE TENSILE STRENGTHS WILL BE MEASURED AS A FUNCTION OF THE SURFACE CHEMICAL MODIFICATION TREATMENT CONDITIONS. FRACTURE SURFACEMORPHOLOGY STUDIES WILL BE CONDUCTED TO ADDRESS CHANGES IN FAILURE SURFACE BEHAVIOR. ANALYTICAL STUDIES WILL BE CONDUCTED, FOR VARIOUS ROTOR DESIGNS, TO DETERMINE THE EFFECT OF INCREASED TRANSVERSE TENSILE STRENGTH ON ENERGY STORAGE CAPABILITY.