Abstract: Embodiments are directed to a pourable foam comprising a first resin component comprising a polymeric methylene diphenyl diisocyanate, a second resin component comprising a polyol, and a barium sulfate powder component. The barium sulfate powder component is combined with the second resin component prior to combining the first and second resin components. The barium sulfate component may comprise between 1% and 50% of the pourable foam. The pourable foam may be used to repair or create aircraft components.

Abstract: In accordance with one embodiment of the present disclosure, a method for manufacturing a honeycomb core sandwich panel includes placing a thermoset facesheet in contact with a thermoplastic honeycomb core without using a separate adhesive and attaching the thermoset facesheet to the thermoplastic honeycomb core by using a curing profile comprising a temperature that is lower than a gel point temperature of the thermoset facesheet and higher than a softening point temperature of the thermoplastic honeycomb core.

Abstract: In accordance with one embodiment of the present disclosure, a method for manufacturing a honeycomb core sandwich panel includes placing a thermoset facesheet in contact with a thermoplastic honeycomb core without using a separate adhesive and attaching the thermoset facesheet to the thermoplastic honeycomb core by using a curing profile comprising a temperature that is lower than a gel point temperature of the thermoset facesheet and higher than a softening point temperature of the thermoplastic honeycomb core.

Abstract: A method of repairing an aircraft component having a structural core surrounded by an exterior skin of composite material includes removing damaged material from the component to create a cavity therein that exposes an undamaged portion of the structural core, applying a septum comprising composite material to the undamaged portion of the structural core within the cavity such that an orientation of fibers in the septum matches an orientation of fibers in the exterior skin, placing a repair core onto the septum in the cavity such that cells of the repair core are in alignment with cells of the undamaged portion of the structural core, inserting a shim into the cavity along a perimeter of the repair core, applying a patch that covers the cavity to the exterior skin, and co-curing the septum, shim, and patch to bond the repair core in place within the cavity.

Abstract: An example of a method of manufacturing a component from a composite prepreg includes collecting a specimen from the composite prepreg and quantifying an amount of surface resin of the specimen by submerging the specimen in a container containing a fluid to determine a fluid pickup percentage. Responsive to a determination that the fluid pickup percentage exceeds a predefined threshold value, forming a component from the composite prepreg.

Abstract: Embodiments are directed to a pourable foam comprising a first resin component comprising a polymeric methylene diphenyl diisocyanate, a second resin component comprising a polyol, and a barium sulfate powder component. The barium sulfate powder component is combined with the second resin component prior to combining the first and second resin components. The barium sulfate component may comprise between 1% and 50% of the pourable foam. The pourable foam may be used to repair or create aircraft components.

Abstract: A method of repairing a composite structure includes providing an assembled composite structure comprising a substantially rigid outer component, wherein the composite structure comprises a void space at least partially bounded by the outer component. The method further includes forming an injection hole through the outer component to provide a path between the void space and space external to the composite structure. The method further includes injecting foam into the void space through the injection hole while the foam is in a substantially unexpanded state and expanding the foam within the void space.

Abstract: An aircraft fuel system includes a fuel cell adapted to contain fuel. A fuel cell receiving assembly has an inner surface adapted to receive the fuel cell. A shaped foam substrate is machined from a foam substrate to fit between the inner surface of the fuel cell receiving assembly and the fuel cell. A polyurea spray coating substantially covers the shaped foam substrate to form a fuel cell cushion. The polyurea spray coating is sprayable onto the shaped foam substrate such that the fuel cell cushion is substantially nonabsorbent of fuel. The fuel cell cushion is interposable between the inner surface of the fuel cell receiving assembly and the fuel cell to cushion the fuel cell from damage.

Abstract: An example of a method of manufacturing a component from a composite prepreg includes collecting a specimen from the composite prepreg and quantifying an amount of surface resin of the specimen by submerging the specimen in a container containing a fluid to determine a fluid pickup percentage. Responsive to a determination that the fluid pickup percentage exceeds a predefined threshold value, forming a component from the composite prepreg.

Abstract: A method of repairing an aircraft component having a structural core surrounded by an exterior skin of composite material includes removing damaged material from the component to create a cavity therein that exposes an undamaged portion of the structural core, applying a septum comprising composite material to the undamaged portion of the structural core within the cavity such that an orientation of fibers in the septum matches an orientation of fibers in the exterior skin, placing a repair core onto the septum in the cavity such that cells of the repair core are in alignment with cells of the undamaged portion of the structural core, inserting a shim into the cavity along a perimeter of the repair core, applying a patch that covers the cavity to the exterior skin, and co-curing the septum, shim, and patch to bond the repair core in place within the cavity.

Abstract: A structure includes a skin and a foam member. The foam member has a molded contour, the mold contour being configured to provide tooled surface for the skin. When the skin is a composite skin, the foam member provides support for the skin so that the skin can be cured under heat and pressure. A method of making the foam member for a foam stiffened structure includes creating a mold having an interior cavity which resembles a desired shape the foam member. A subsequent step involves introducing a foam mixture into the mold. Next, the foam mixture is allowed to polymerize so as to expand and distribute within the cavity of the mold. The method further includes selectively controlling a density of the foam member in the mold. The foam member is at least partially cured. The foam member is assembled with a skin to produce the foam stiffened structure.

Abstract: A method is provided in one example embodiment and may include positioning at least one nozzle within a hollow portion of a rotor blade at a distance associated with a span of the rotor blade and providing, via the at least one nozzle, a liquid foam mixture in the hollow portion, wherein the liquid foam expands and becomes a solid foam material that fills the hollow portion of the rotor blade. Another method is provided in another example embodiment and may include providing a plurality of openings for a rotor blade that are positioned proximate to a hollow portion of the rotor blade and providing a liquid foam mixture in the hollow portion of the rotor blade through at least one opening of the rotor blade, wherein the liquid foam mixture expands and becomes a solid foam material that fills the hollow portion of the rotor blade.

Abstract: A method is provided in one example embodiment and may include forming a ply stack comprising a plurality of uncured composite plies, wherein one or more uncured composite ply of the plurality of uncured composite plies comprises a plurality of perforations that extend, at least partially, through a thickness of the one or more uncured composite ply; and compacting the ply stack to form a composite structure. The plurality of perforations may provide paths for volatiles to be removed through the thickness of the one or more uncured composite ply of the ply stack during the compacting. Volatiles may also be removed through edges of the ply stack during the compacting. In some instances, all uncured composite plies of the ply stack may include a plurality of perforations that extend, at least partially, through the thickness of each uncured composite ply.

Abstract: In accordance with one embodiment of the present disclosure, a method for manufacturing a honeycomb core sandwich panel includes placing a thermoset facesheet in contact with a thermoplastic honeycomb core without using a separate adhesive and attaching the thermoset facesheet to the thermoplastic honeycomb core by using a curing profile comprising a temperature that is lower than a gel point temperature of the thermoset facesheet and higher than a softening point temperature of the thermoplastic honeycomb core.

Abstract: A method of repairing a composite structure includes providing an assembled composite structure comprising a substantially rigid outer component, wherein the composite structure comprises a void space at least partially bounded by the outer component. The method further includes forming an injection hole through the outer component to provide a path between the void space and space external to the composite structure. The method further includes injecting foam into the void space through the injection hole while the foam is in a substantially unexpanded state and expanding the foam within the void space.

Abstract: In accordance with one embodiment of the present disclosure, a method for manufacturing a honeycomb core sandwich panel includes placing a thermoset facesheet in contact with a thermoplastic honeycomb core without using a separate adhesive and attaching the thermoset facesheet to the thermoplastic honeycomb core by using a curing profile comprising a temperature that is lower than a gel point temperature of the thermoset facesheet and higher than a softening point temperature of the thermoplastic honeycomb core.

Abstract: A method is provided in one example embodiment and may include positioning at least one nozzle within a hollow portion of a rotor blade at a distance associated with a span of the rotor blade and providing, via the at least one nozzle, a liquid foam mixture in the hollow portion, wherein the liquid foam expands and becomes a solid foam material that fills the hollow portion of the rotor blade. Another method is provided in another example embodiment and may include providing a plurality of openings for a rotor blade that are positioned proximate to a hollow portion of the rotor blade and providing a liquid foam mixture in the hollow portion of the rotor blade through at least one opening of the rotor blade, wherein the liquid foam mixture expands and becomes a solid foam material that fills the hollow portion of the rotor blade.

Abstract: A method is provided in one example embodiment and may include forming a ply stack comprising a plurality of uncured composite plies, wherein one or more uncured composite ply of the plurality of uncured composite plies comprises a plurality of perforations that extend, at least partially, through a thickness of the one or more uncured composite ply; and compacting the ply stack to form a composite structure. The plurality of perforations may provide paths for volatiles to be removed through the thickness of the one or more uncured composite ply of the ply stack during the compacting. Volatiles may also be removed through edges of the ply stack during the compacting. In some instances, all uncured composite plies of the ply stack may include a plurality of perforations that extend, at least partially, through the thickness of each uncured composite ply.

Abstract: Systems and methods of operating a test apparatus to simulate testing a production aircraft component include assembling a test assembly having a test specimen and a wear protection material disposed on opposing sides of the test specimen, an outer plate disposed on each side of the test specimen in contact with the wear protection material, and a bolt disposed through the test specimen and the outer plates and applying a preload against the wear protection material. The test assembly is secured in a test machine, and the test machine is operated to provide a predetermined displacement of the test specimen relative to the outer plates at a predetermined frequency at a determined frequency of displacement cycles. The preload, the predetermined displacement, and the predetermined frequency of displacement cycles are determined through finite element analysis of an analytical model of the production component.

Abstract: An aircraft fuel system includes one or more fuel cells adapted to contain fuel, a fuel cell receiving assembly having an inner surface adapted to receive the one or more fuel cells and a fuel cell cushion disposed between the inner surface of the fuel cell receiving assembly and the one or more fuel cells. The fuel cell cushion is machined from a foam substrate to form a shaped foam substrate that is substantially covered with a cushion coating. The cushion coating is sprayable onto the shaped foam substrate such that the fuel cell cushion is substantially nonabsorbent of fuel. The fuel cell cushion is interposable between the inner surface of the fuel cell receiving assembly and the one or more fuel cells to cushion the one or more fuel cells from damage.