Abstract: A method and apparatus for determining stiffness of a plate-like structure including a monolithic or composite laminate plate entails disposing a device for generating an acoustical pulse against a surface of the plate and disposing a detecting device against the same surface spaced a known distance from the pulse-generating device, and using the pulse-generating device to emit a pulse so as to create an extensional wave in the plate. The detecting device is used to determine a time of flight of the wave over the known distance, and the wave velocity is calculated. A Young's modulus of the plate is determined by a processor based on the wave velocity. Methods and apparatus for evaluating both isotropic plates and anisotropic laminates are disclosed.

Abstract: A method and apparatus for determining stiffness of a plate-like structure including a monolithic or composite laminate plate entails disposing a device for generating an acoustical pulse against a surface of the plate and disposing a detecting device against the same surface spaced a known distance from the pulse-generating device, and using the pulse-generating device to emit a pulse so as to create an extensional wave in the plate. The detecting device is used to determine a time of flight of the wave over the known distance, and the wave velocity is calculated. A Young's modulus of the plate is determined by a processor based on the wave velocity. Methods and apparatus for evaluating both isotropic plates and anisotropic laminates are disclosed.

Abstract: A method for determining stiffness of a composite laminate plate entails disposing a device for generating an acoustical pulse against a surface of the plate and disposing a detecting device against the same surface spaced a known distance from the pulse-generating device, and using the pulse-generating device to emit a pulse so as to create an extensional wave in the plate. The detecting device is used to determine a time of flight of the wave over the known distance, and the wave velocity is calculated. A Young's modulus of the plate is determined based on the wave velocity. Methods for both anisotropic and quasi-isotropic laminates are disclosed.

Abstract: A back-up tooling apparatus for supporting the inner side of a hollow cylindrical workpiece during a circumferential friction stir weld includes a plurality of arcuate shoes configured to mate end-to-end to form a substantially continuous ring, and an expandable support for supporting the shoes and operable to retract and expand the shoes inward and outward. The expandable support includes at least one rotatable feed screw and central support members mounted on the feed screw or screws and pivotally connected to the shoes by support arms. The central support members are moved axially toward or away from each other for expanding or retracting the shoes. The shoes in one embodiment overlap in the circumferential direction, and a seal material is disposed between mating end faces of adjacent shoes. A restraining device is provided for clamping about the workpiece to reduce thermal expansion thereof. Cable-and-winch and geared drive devices are provided for rotatably driving the workpiece from its outer surface.

Abstract: A method and apparatus for applying a coating composition to a surface on at least one panel member using a fastener having the composition on its exterior. The fastener, which has a greater coefficient of thermal expansion, is fitted within the panel member, and during thermally-induced expansion, acts to facilitate diffusion of the composition into the panel surface. The coating composition is applied to the fastener via conventional methods to the fastener, and is engineered to react with the material of the panel member to form, via a diffusion process, an intermediate coating in the region of the panel member and coating materials.

Abstract: Apparatus and a method are disclosed for eliminating fiber distortions ("fiber swimming") and separations ("fiber fish eyes") via a premliminary step taken prior to consolidation of "green", fiber-reinforced metal matrix materials. The apparatus includes a first member for supporting the "green" metal matrix material pack, a second member to cover the "green" pack, the thermal coefficient of expansion of the first member being smaller than the thermal coefficient of expansion of the second member, the second member being secured to the first member atop the "green" pack to form a retort, and the entire retort being heated to an off-gassing temperature, where the second member bows outwardly away from the pack to relieve pressure from the pack.

Abstract: A method of precision cutting fabric material while obtaining cleanly cut edges involves placing the material on a flat support surface, identifying one or more regions of material to be cut, placing adhesive tape on both sides of the material, and then using an appropriate tool to first squeeze the tape into the fabric at the cutting region, and effecting the cutting of the taped material. A reinforcing woven fabric constituent for incorporation into a metal matrix composite, produced by the method, is also disclosed.

Abstract: A method and apparatus for forming cleanly defined holes through reinforced metal matrix material includes a drill bit with a shank portion and flutes on said shank portion, the drill bit capable of withstanding a chip load of at least about 0.008 inch/rev/flute, and preferably in the range of from about 0.008 inch/rev/flute to about 0.012 inch/rev/flute, achieved through turning the bit at a speed within the range of about 18 surface feet per minute ("sfpm") to about 20 sfpm, and advancing the bit at an aggressive rate through the metal matrix material at a rate of from about 3 inches per minute to about 6 inches per minute.