Abstract: A method for forming a ceramic-based material comprises depositing a ceramic-precursor composition comprising nanoparticles having at least one dimension less than 100 nm and an aspect ratio of 1.5 or greater, and a carrier fluid on a surface of a substrate to form an as-deposited layer of the ceramic precursor composition; and sintering the as-deposited layer of the ceramic precursor composition at a sintering temperature to form a ceramic-based material.

Abstract: Systems and methods for producing a preform for a composite member. An exemplary method includes preparing a lay-up of reinforcement layers and thermoplastic interlayers, and transferring the lay-up to a preform tool. The method further includes inducing heat in the preform tool to a transition-temperature range that causes the thermoplastic interlayers to become tacky or viscous, and applying pressure to the lay-up with the preform tool to shape the lay-up into the preform.

Abstract: Systems and methods for producing a preform for a composite member. An exemplary method includes preparing a lay-up of reinforcement layers and thermoplastic interlayers, and transferring the lay-up to a preform tool. The method further includes inducing heat in the preform tool to a transition-temperature range that causes the thermoplastic interlayers to become tacky or viscous, and applying pressure to the lay-up with the preform tool to shape the lay-up into the preform.

Abstract: A method for fabricating a stiffened panel. Layers of composite material are placed on a surface of an inner-mold-line tool having protrusions that extend from the surface of the inner-mold-line tool. The layers of composite material laid-up on the surface of the inner-mold-line tool are compacted to form compacted layers of composite material. The compacted layers of composite material are cured to form an inner-mold-line layer having corresponding protrusions. The inner-mold-line layer is joined to an outer-mold-line layer.

Abstract: There is provided a method of making a hollow fiber. The method includes mixing, in a first solvent, a plurality of nanostructures, one or more first polymers, and a fugitive polymer which is dissociable from the nanostructures and the one or more first polymers, to form an inner-volume portion mixture. The method further includes mixing, in a second solvent, one or more second polymers to form an outer-volume portion mixture, and spinning the inner-volume portion mixture and the outer-volume portion mixture to form a precursor fiber. The method further includes heating the precursor fiber to oxidize the precursor fiber and to change a molecular-bond structure of the precursor fiber, and during heating, extracting the fugitive polymer from the inner-volume portion mixture. The method further includes obtaining the hollow fiber with the inner-volume portion having the nanostructures and the first polymers, and with the outer-volume portion having the second polymers.

Abstract: There is provided a method of making a hollow fiber. The method includes mixing, in a first solvent, a plurality of nanostructures, one or more first polymers, and a fugitive polymer which is dissociable from the nanostructures and the one or more first polymers, to form an inner-volume portion mixture. The method further includes mixing, in a second solvent, one or more second polymers to form an outer-volume portion mixture, and spinning the inner-volume portion mixture and the outer-volume portion mixture to form a precursor fiber. The method further includes heating the precursor fiber to oxidize the precursor fiber and to change a molecular-bond structure of the precursor fiber, and during heating, extracting the fugitive polymer from the inner-volume portion mixture. The method further includes obtaining the hollow fiber with the inner-volume portion having the nanostructures and the first polymers, and with the outer-volume portion having the second polymers.

Abstract: A composite structure and method of assembling a composite structure is provided. The composite structure includes a base member having an outer surface and an inner surface. The inner surface defines a channel therethrough. The composite structure further includes a support member coupled to the outer surface. A fabric overwrap is coupled to the support member.

Abstract: There is provided a method of making a hollow fiber having improved resistance to microfracture formation at a fiber-matrix interface. The method includes mixing in a first solvent a plurality of nanostructures, one or more first polymers, and a fugitive polymer which is dissociable from the nanostructures and the one or more first polymers, to form an inner-volume portion mixture. The method further includes mixing in a second solvent one or more second polymers to form an outer-volume portion mixture, spinning the inner-volume portion mixture and the outer-volume portion mixture and extracting the fugitive polymer from the inner-volume portion mixture to form a precursor fiber, heating the precursor fiber to oxidize the precursor fiber and to change a molecular-bond structure of the precursor fiber, and obtaining a hollow fiber with the inner-volume portion having the nanostructures and the first polymers, and with the outer-volume portion having the second polymers.

Abstract: There is provided a method of making a fiber having improved resistance to microfracture formation at a fiber-matrix interface. The method includes mixing a plurality of nanostructures and one or more first polymers in a first solvent to form an inner-volume portion mixture, mixing one or more second polymers in a second solvent to form an outer-volume portion mixture, spinning the inner-volume portion mixture and the outer-volume portion mixture to form a precursor fiber, heating the precursor fiber to oxidize the precursor fiber and to change a molecular-bond structure of the precursor fiber, and obtaining a fiber. The fiber has an inner-volume portion with a first outer diameter, the nanostructures, and with the one or more first polymers, and has an outer-volume portion with a second outer diameter and the one or more second polymers, the outer-volume portion being in contact with and completely encompassing the inner-volume portion.

Abstract: A method for fabricating a stiffened panel. Layers of composite material are placed on a surface of an inner-mold-line tool having protrusions that extend from the surface of the inner-mold-line tool. The layers of composite material laid-up on the surface of the inner-mold-line tool are compacted to form compacted layers of composite material. The compacted layers of composite material are cured to form an inner-mold-line layer having corresponding protrusions. The inner-mold-line layer is joined to an outer-mold-line layer.

Abstract: A composite structure and method of assembling a composite structure is provided. The composite structure includes a base member having an outer surface and an inner surface. The inner surface defines a channel therethrough. The composite structure further includes a support member coupled to the outer surface. A fabric overwrap is coupled to the support member.

Abstract: A composite structure and method of assembling a composite structure is provided. The composite structure includes a base member having an outer surface and an inner surface. The inner surface defines a channel therethrough. The composite structure further includes a support member coupled to the outer surface. A fabric overwrap is coupled to the support member.

Abstract: Dinadic phenyl amine reactive endcap monomers for application in high-temperature polymeric composites are described. The amine group of the endcap is directly reacted with a desired chemical backbone to provide the preferred rigidity and chemical resistance. The ability of the amine group to react with a wide variety of chemical backbones allows the tailoring of formulations for various application temperatures, mechanical properties, processes and resistances while retaining the high degree of crosslinking that yields excellent temperature stability, ease of processing and the necessary toughness. Polyimide oligomers comprising the reaction product of at least one dinadic phenyl amine endcap monomer and a chemical backbone, preferably with a molecular weight not exceeding about 1000-3000, suitable for high temperature composites are described. The dinadic phenyl amine endcaps may be reacted with an acid anhydride capped precursor to form polyimide resins suitable for high-temperature composites.

Abstract: There is provided a fiber and method of making a fiber. The fiber has an inner-volume portion having a first outer diameter, a plurality of nanostructures, and one or more first polymers. The nanostructures act as an orientation template for orientation of the one or more first polymers in a direction parallel to a longitudinal axis of the fiber. The fiber has an outer-volume portion having a second outer diameter and one or more second polymers. The outer-volume portion is in contact with and completely encompasses the inner-volume portion. The inner-volume portion has at least one of a tensile modulus and a strength that are higher than at least one of a tensile modulus and a strength of the outer-volume portion.

Abstract: There is provided a hollow fiber and method of making. The hollow fiber has an inner-volume portion having a first-core portion and one or more hollow second-core portions. The first-core portion has nanostructures and one or more first polymers. The nanostructures act as an orientation template for orientation of the first polymers in a direction parallel to a longitudinal axis of the fiber. The first-core portion is in contact with and encompasses the hollow second-core portions. The hollow fiber further has an outer-volume portion having one or more second polymers. The outer-volume portion is in contact with and completely encompasses the inner-volume portion. The inner-volume portion has at least one of a tensile modulus and a strength that are higher than at least one of a tensile modulus and a strength of the outer-volume portion.

Abstract: There is provided a method of making a fiber having improved resistance to microfracture formation at a fiber-matrix interface. The method includes mixing a plurality of nanostructures and one or more first polymers in a first solvent to form an inner-volume portion mixture, mixing one or more second polymers in a second solvent to form an outer-volume portion mixture, spinning the inner-volume portion mixture and the outer-volume portion mixture to form a precursor fiber, heating the precursor fiber to oxidize the precursor fiber and to change a molecular-bond structure of the precursor fiber, and obtaining a fiber. The fiber has an inner-volume portion with a first outer diameter, the nanostructures, and with the one or more first polymers, and has an outer-volume portion with a second outer diameter and the one or more second polymers, the outer-volume portion being in contact with and completely encompassing the inner-volume portion.

Abstract: There is provided a method of making a hollow fiber having improved resistance to microfracture formation at a fiber-matrix interface. The method includes mixing in a first solvent a plurality of nanostructures, one or more first polymers, and a fugitive polymer which is dissociable from the nanostructures and the one or more first polymers, to form an inner-volume portion mixture. The method further includes mixing in a second solvent one or more second polymers to form an outer-volume portion mixture, spinning the inner-volume portion mixture and the outer-volume portion mixture and extracting the fugitive polymer from the inner-volume portion mixture to form a precursor fiber, heating the precursor fiber to oxidize the precursor fiber and to change a molecular-bond structure of the precursor fiber, and obtaining a hollow fiber with the inner-volume portion having the nanostructures and the first polymers, and with the outer-volume portion having the second polymers.

Abstract: Systems and methods for producing a preform for a composite member. An exemplary method includes preparing a lay-up of reinforcement layers and thermoplastic interlayers, and transferring the lay-up to a preform tool. The method further includes inducing heat in the preform tool to a transition-temperature range that causes the thermoplastic interlayers to become tacky or viscous, and applying pressure to the lay-up with the preform tool to shape the lay-up into the preform.

Abstract: A method of making a coated polymer-matrix composite (PMC) having high-temperature oxidation protection includes bonding a first surface of a flexible sublayer that is free of water to a first surface of a dry PMC substrate having a first coefficient of thermal expansion. The flexible sublayer includes an electrically conductive material in an effective amount to enable electrical conductivity of the flexible sublayer, and includes a low-modulus-of-elasticity material. The method includes heating the bonded flexible sublayer and the PMC substrate, and bonding a first surface of an oxygen-impervious, dense barrier-coating layer to a second surface of the flexible sublayer to form the coated PMC having high-temperature oxidation protection.

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.