THERAPEUTIC ANGIOGENESIS BY SF/HGF GENE TRANSFER

Not Available High Cycle Fatigue (HCF) is affecting aircraft system readiness, operability and cost of ownership. State-of-the-art passive damping treatments, while effective, are limited to temperatures below 500 degrees F and to static structures. The needs and environment posed by gas turbine engines far exceed the limitations of the available viscoelastic damping treatments. MiTi has conceived a powder structural damping approach that is insensitive to temperature and accounts for the high centrifugal loads encountered in rotating airfoils. Initial powder damping feasibility has been demonstrated and powder material damping characteristics are being experimentally determined. Transfer of this new technology to practical applications requires evaluation in structural elements to verify the proposed design stategies. In support of this program and to ensure technology transfer to product, major engine company support has been obtained. Specific objectives of this program are to 1) develop a high temperature powder damping design methodology for both rotating and static structural elements, 2) design and build a powder damped cantilever beam test specimen using powder material damping data presently being acquired under Air Force sponsorship, 3) fabricate the cantilever beam test specimen and demonstrate the effect of powder damping in controlling blade vibratory response, and 4) prepare a preliminary design of a simulated blade for detailed static and rotating verification testing