Abstract: A honeycomb structure that includes cells in which septums are located to provide acoustic dampening. The cells are formed by at least four walls wherein at least two of the walls are substantially parallel to each other. The septums include warp fibers and weft fibers that are substantially perpendicular to each other. The septums are oriented in the honeycomb cells such that the weft fibers and/or warp fibers are substantially perpendicular to the parallel walls.

Abstract: The invention is directed to carbon fibers having high tensile strength and modulus of elasticity. The invention also provides a method and apparatus for making the carbon fibers. The method comprises advancing a precursor fiber through an oxidation oven wherein the fiber is subjected to controlled stretching in an oxidizing atmosphere in which tension loads are distributed amongst a plurality of passes through the oxidation oven, which permits higher cumulative stretches to be achieved. The method also includes subjecting the fiber to controlled stretching in two or more of the passes that is sufficient to cause the fiber to undergo one or more transitions in each of the two or more passes. The invention is also directed to an oxidation oven having a plurality of cooperating drive rolls in series that can be driven independently of each other so that the amount of stretch applied to the oven in each of the plurality of passes can be independently controlled.

Abstract: The invention is directed to carbon fibers having high tensile strength and modulus of elasticity. The invention also provides a method and apparatus for making the carbon fibers. The method comprises advancing a precursor fiber through an oxidation oven wherein the fiber is subjected to controlled stretching in an oxidizing atmosphere in which tension loads are distributed amongst a plurality of passes through the oxidation oven, which permits higher cumulative stretches to be achieved. The method also includes subjecting the fiber to controlled stretching in two or more of the passes that is sufficient to cause the fiber to undergo one or more transitions in each of the two or more passes. The invention is also directed to an oxidation oven having a plurality of cooperating drive rolls in series that can be driven independently of each other so that the amount of stretch applied to the oven in each of the plurality of passes can be independently controlled.

Abstract: A load-bearing composite structure for connection to a support body or structure. The load-bearing structure includes a load-bearing element that is made up of continuous reinforcing fibers and a resin matrix. The load-bearing element has an attachment portion for connection to the support body. The load-bearing composite structure further includes a connection element that is formed using a molding material which is composed of discontinuous fibers and a resin matrix. The molding material is molded over the surface of the attachment portion of the load-bearing element.

Abstract: The bandwidth or acoustical range of a nacelle or other type of acoustic structure is increased by acoustically coupling honeycomb cells together to form pairs of acoustic cells that have an effective acoustic or resonator length that is up to twice that of either acoustic cell taken alone.

Abstract: Honeycomb sections are bonded together with seams made up of an adhesive that is carried by a honeycomb seam support or a linked-segment seam support. The seams are particularly useful for splicing together curved honeycomb sections that contain acoustic septum. The curved acoustic honeycomb sections are spliced or seamed together to form engine nacelles and other acoustic dampening structures.

Abstract: A module (1) for holding at least one bushing (17) within a recess, wherein it comprises two side surfaces (2, 3), an upper (4) and a lower (5) surface and at least one end surface (6), wherein the upper (4) and lower (5) surfaces are of different width and arcs, respectively, in their cross-section, and the side surfaces (2, 3) are of equal height, and when coupled to a second module (8) by its side surfaces (3, 9), which second module (8) optionally may also hold at least one bushing (17), the sum of the angle (alpha) between the optionally imaginary plane side surface (12) of the one module (1) and the tangent (10) to its upper surface (4) at the intersection (A) with the side surface (3) and the angle (beta) between the optionally imaginary plane side surface (13) of the other module (8) and the tangent (11) to its upper surface (15) at the intersection (B) with the side surface (9) is at least 180 degrees and/or a plurality of modules (1), optionally when holding the bushings (17), form at least a sectio

Abstract: Composite material that contain epoxy resin which is toughened and strengthened with thermoplastic materials and a blend of insoluble particles. The uncured matrix resins include an epoxy resin component, a soluble thermoplastic component, a curing agent and an insoluble particulate component composed of elastic particles and rigid particles. The uncured resin matrix is combined with a fibrous reinforcement and cured/molded to form composite materials that may be used for structural applications, such as primary structures in aircraft.

Abstract: Honeycomb sections are bonded together with seams made up of an adhesive that is carried by a honeycomb seam support or a linked-segment seam support. The seams are particularly useful for splicing together curved honeycomb sections that contain acoustic septum. The curved acoustic honeycomb sections are spliced or seamed together to form engine nacelles and other acoustic dampening structures.

Abstract: Methods and apparatus are provided for making a rotor blade spar from composite material wherein a multi-component mandrel is used to form the composite spar. The mandrel is made using a number of components that are assembled and held in place using a roller assembly. The roller assembly is removed after pre-cure lay up and compaction of the composite material. Once the roller assembly is removed, the remaining mandrel components can be separated from each other and easily removed from the spar. The mandrel components, including the roller assembly, can then be re-assembled and re-used to form additional composite spars.

Abstract: Composite material that contain epoxy resin which is toughened and strengthened with thermoplastic materials and a blend insoluble particles. The uncured matrix resins include an epoxy resin component, a soluble thermoplastic component, a curing agent and an insoluble particulate component composed of elastic particles and rigid particles. The uncured resin matrix is combined with a fibrous reinforcement and cured/molded to form composite materials that may be used for structural applications, such as primary structures in aircraft.

Abstract: Composite pre-forms are molded at high pressure to form composite parts that can be used in place of metal-based high performance parts, such as the outlet guide vanes found in turbofan jet engines. The composite pre-forms include two different fiber orientations that are co-molded in a resin matrix at high pressures to provide composite outlet guide vanes and other high performance parts. Chambers within the composite part are optionally formed during molding of the pre-form at high pressures.

Abstract: An acoustic structure that includes a honeycomb having cells in which septum caps are located. The septum caps are formed from sheets of flexible material that may be perforated before or after the material is inserted into the honeycomb. The flexible material is sufficiently flexible to allow folding into the shape of a septum cap. The flexible material is also sufficiently stiff to provide frictional engagement and locking of the septum cap to the honeycomb cell when the cap is inserted into the honeycomb during fabrication of the acoustic structure. An adhesive is applied to the septum caps after the caps have been inserted into the honeycomb cells to provide a permanent bond.

Abstract: Prepreg that contains epoxy resin compositions that include an epoxy resin component and a curative powder comprising particles of 4,4?-diaminobenzanilide (DABA) wherein the size of the DABA particles is less than 100 microns and wherein the median particle size is below 20 microns.

Abstract: Composite materials that contain thermoplastic-toughened cyanate ester resins as the resin matrix. The composite materials exhibit low levels of heat release when burned. The matrix resins are composed of from 50 to 80 weight percent of a cyanate ester resin component. The matrix resin composition also includes from 10 to 40 weight percent of a thermoplastic blend that is composed of polyetherimide and polyamideimide. The epoxy resin composition further includes from 1 to 10 weight percent of a curative agent. The composite materials may be used for primary structures in aircraft and other load-bearing structures.

Abstract: A honeycomb structure that includes cells in which septums are located to provide acoustic dampening. The cells are formed by at least four walls wherein at least two of the walls are substantially parallel to each other. The septums include warp fibers and weft fibers that are substantially perpendicular to each other. The septums are oriented in the honeycomb cells such that the weft fibers and/or warp fibers are substantially perpendicular to the parallel walls.

Abstract: Quasi-isotropic chopped prepreg is used to make parts found in aerospace vehicles. Exemplary aerospace parts that are made using quasi-isotropic chopped prepreg include aircraft window frames, wing fairing supports, flange supports, frame gussets, rudder actuator brackets, shear ties, seat pedestals, cargo floor flange supports, storage bin fittings, antenna supports, torque tube pans, handle boxes, side guide fittings, wing box covers and intercostals.

Abstract: Composite materials that contain thermoplastic-toughened cyanate ester resins as the resin matrix. The composite materials exhibit low levels of heat release when burned. The matrix resins are composed of from 50 to 80 weight percent of a cyanate ester resin component. The matrix resin composition also includes from 10 to 40 weight percent of a thermoplastic blend that is composed of polyetherimide and polyamideimide. The epoxy resin composition further includes from 1 to 10 weight percent of a curative agent. The composite materials may be used for primary structures in aircraft and other load-bearing structures.

Abstract: Layers of unidirectional (UD) fiber prepreg are formed into a pre-plied, multi-directional, continuous fiber laminate that is used as a molding compound to form three dimensional structures. Cut-outs from the laminate are slotted and folded along fold lines to provide near-net-shaped preforms that may be compression molded to form fiber-reinforced composite structures having complex shapes.

Abstract: Composite materials that contain thermoplastic-toughened cyanate ester resins as the resin matrix. The composite materials exhibit low levels of heat release when burned. The matrix resins are composed of from 50 to 80 weight percent of a cyanate ester resin component. The matrix resin composition also includes from 10 to 40 weight percent of a thermoplastic blend that is composed of polyetherimide and polyamideimide. The epoxy resin composition further includes from 1 to 10 weight percent of a curative agent. The composite materials may be used for primary structures in aircraft and other load-bearing structures.