Abstract: A method of forming a preform may include providing a layer of tackified fibrous material containing structural fibers and resin. The layer may be passed through a forming die set having a die cross-sectional shape. The thermoplastic resin may be heated. The layer may be formed into the die cross-sectional shape. The thermoplastic resin may be allowed to solidify in a manner such that a preform is formed having the die cross-sectional shape.

Abstract: A method of forming a preform may include providing a layer of tackified fibrous material containing structural fibers and resin. The layer may be passed through a forming die set having a die cross-sectional shape. The thermoplastic resin may be heated. The layer may be formed into the die cross-sectional shape. The thermoplastic resin may be allowed to solidify in a manner such that a preform is formed having the die cross-sectional shape.

Abstract: A computer implemented method, apparatus, and computer usable program code for designing a product using technology readiness levels for materials. Entries identifying materials and technology readiness levels for the materials are stored in a database. A first design is developed using a first material selected from the database, wherein the first material has a first technology readiness level identified from the database. A second design is developed using a second material selected from the database, wherein the second material has a second technology readiness level identified from the database. The first design is compared to the second design using the first technology readiness level and the second technology readiness level to form a comparison. A selection is made between the first design and the second design using the comparison.

Abstract: A method is provided for testing structural-acoustic systems using a shaker table. The method includes subjecting a panel structure design to a computational acoustic load and a computational vibration load. The method then computes the ratio of the panel structure maximum response to the acoustic load to the panel structure maximum response to the vibration load. The ratio of these two maximum responses provides a conversion factor for linking an acoustic environment to a vibration environment. Using the conversion factor, the method converts a sonic pressure load for the panel structure to a vibration load. The vibration load is then applied to a panel structure using a shaker table.

Abstract: A method of making an monolithic metallic sandwich structure includes selecting at least two chemically clean metal core sheets having superplastic characteristics and placing them face-to-face. The core sheets are welded together into a core pack along intersecting lines that will form junction lines of webs defining cells between the core sheets when the core pack is expanded superplastically. Gaps are left adjacent to the intersections of the weld lines to produce openings through which gas can pass to pressurize each cell. The position of the gaps adjacent the weld line intersections minimizes strain on the marginal regions around the openings as the core pack is inflated, to reduce the tendency of the sheets to tear or rupture around the openings. A gas pressure line fitting is inserted between one edge and the core pack is welded around its periphery with the gas fitting protruding from the edge for connection to a gas source that will purge and pressurize the core pack with gas.

Abstract: An aircraft fuel tank construction for providing enhanced fuel tank survivability and aircraft structural integrity when the fuel tank is penetrated by an exploding projectile, utilizes selective placement of low density, fluid-displacing material to create a low shock impedance region which decouples protected fuel tank structure from the destructive effects of a shock wave. The low shock impedance region may be formed using closed cell foam, or using isolators comprising bladders inflated with a compressible, inert gas. Such bladders should have a wedge shape and a wedge angle of at least 15 degrees. Precise shape is less important with closed cell foam. Polymethylacrilimide has been shown to be particularly effective for this purpose. Finite element analysis is useful in tuning the design of actual low shock impedance regions for actual aircraft designs.