Abstract: Composite sections for aircraft fuselages and other structures, and methods and systems for manufacturing such sections, are disclosed herein. A method for manufacturing a shell structure in accordance with one embodiment of the invention includes applying composite material to an interior mold surface of a tool to form a skin extending 360 degrees around an axis. The method can further include positioning a plurality of stiffeners on an inner surface of the skin. After the stiffeners have been positioned, a vacuum bag can be installed over the stiffeners and evacuated to press the stiffeners and the skin outwardly against the interior mold surface of the tool. Next, the skin/stiffener combination can be cocured to bond the stiffeners to the skin and harden the shell structure.

Abstract: A bonded composite joint may include a base having a foot configured to couple to a member. The base may include a flange extending outward from the foot. The joint further may include a panel having a core positioned between opposing skins, where the skins have inner walls proximate the core and the skins extend outward beyond the core on at least one end of the panel to define a recess between the skins. The recess between the skins may receive the flange. A bonding agent may be used to couple the flange to the inner walls of the panel.

Abstract: A bonded composite joint may include a base having a foot configured to couple to a member. The base may include a flange extending outward from the foot. The joint further may include a panel having a core positioned between opposing skins, where the skins have inner walls proximate the core and the skins extend outward beyond the core on at least one end of the panel to define a recess between the skins. The recess between the skins may receive the flange. A bonding agent may be used to couple the flange to the inner walls of the panel.

Abstract: A bonded composite joint may include a base having a foot configured to couple to a member. The base may include a flange extending outward from the foot. The joint further may include a panel having a core positioned between opposing skins, where the skins have inner walls proximate the core and the skins extend outward beyond the core on at least one end of the panel to define a recess between the skins. The recess between the skins may receive the flange. A bonding agent may be used to couple the flange to the inner walls of the panel.

Abstract: Embodiments of methods and apparatus for providing a double shear joint for bonding in structural applications are disclosed. In one embodiment, a bonded composite joint includes a base having a foot configured to couple to a member, the base including a flange extending outward from the foot. The joint further includes a panel having a core configured between opposing skins, the skins having inner walls proximate the core, the skins extending outward beyond the core on at least one end of the panel to define a recess between the skins, the recess configured to receive the flange. A bonding agent is used to couple the flange to the inner walls of the panel.

Abstract: Composite sections for aircraft fuselages and other structures, and methods and systems for manufacturing such sections, are disclosed herein. A method for manufacturing a shell structure in accordance with one embodiment of the invention includes applying composite material to an interior mold surface of a tool to form a skin extending 360 degrees around an axis. The method can further include positioning a plurality of stiffeners on an inner surface of the skin. After the stiffeners have been positioned, a vacuum bag can be installed over the stiffeners and evacuated to press the stiffeners and the skin outwardly against the interior mold surface of the tool. Next, the skin/stiffener combination can be cocured to bond the stiffeners to the skin and harden the shell structure.

Abstract: The off-part motion of an automatic composite tape laydown head is optimized to increase the overall rate at which tape is laid down to form doublers in a composite structure layup. Starting and stopping gates for each doubler are determined based on ply data and course definitions for the doublers. Using the gate locations, multiple possible paths between the doublers are analyzed to determine the best course for optimizing tape head travel. The selected course is used by an NC program that controls the operation of the tape head.

Abstract: Composite sections for aircraft fuselages and other structures, and methods and systems for manufacturing such sections, are disclosed herein. A method for manufacturing a shell structure in accordance with one embodiment of the invention includes applying composite material to an interior mold surface of a tool to form a skin extending 360 degrees around an axis. The method can further include positioning a plurality of stiffeners on an inner surface of the skin. After the stiffeners have been positioned, a vacuum bag can be installed over the stiffeners and evacuated to press the stiffeners and the skin outwardly against the interior mold surface of the tool. Next, the skin/stiffener combination can be cocured to bond the stiffeners to the skin and harden the shell structure.

Abstract: A hat stringer inspection device permits continuous inspection of hat stringers as one or more probes are moved along the length of the hat stringer. Probes may be magnetically coupled to opposing surfaces of the structure, including, for example, where one of the probes is positioned inside the hat stringer and the probes are magnetically coupled across the surface of the hat stringer. The device may be autonomous with a feedback-controlled motor to drive the inspection device along the hat stringer. Magnetic coupling is also used to re-orient the position and/or alignment of the probes with respect to changes in the hat stringer or shapes, sizes, and configurations of hat stingers.

Abstract: A hat stringer inspection device permits continuous inspection of hat stringers as one or more probes are moved along the length of the hat stringer. Probes may be magnetically coupled to opposing surfaces of the structure, including, for example, where one of the probes is positioned inside the hat stringer and the probes are magnetically coupled across the surface of the hat stringer. The device may be autonomous with a feedback-controlled motor to drive the inspection device along the hat stringer. Magnetic coupling is also used to re-orient the position and/or alignment of the probes with respect to changes in the hat stringer or shapes, sizes, and configurations of hat stingers.

Abstract: Fire retardant and heat resistant yarns, fabrics, and other fibrous blends incorporate one or more fire retardant and heat resistant strands comprising oxidized polyacrylonitrile and one or more strengthening filaments such as metallic filaments (e.g., stainless steel), high strength ceramic filaments, or high strength polymer filaments. Such yarns, fabrics, and other fibrous blends have a superior tensile strength, cut resistance, abrasion resistance, LOI, TPP and continuous operating temperature compared to conventional fire retardant fabrics. The yarns, fabrics, and other fibrous blends are also more soft, supple, breathable and moisture absorbent and are therefore more comfortable to wear, compared to conventional fire retardant fabrics. The inventive yarns may be woven, knitted or otherwise assembled into a desired fabric or other article of manufacture.

Abstract: A method generally includes electronically accessing positional data defining a defect location on a composite structure, and automatically causing a material placement machine to return to the defect location as defined by the positional data. The method can also include automatically causing the material placement machine to place or lay down material sufficient for repairing a defect at the defect location. Alternatively, the material placement machine may automatically return to a defect location, and then an operator may manually repair the defect at the defect location.

Abstract: Fire retardant and heat resistant yarns, fabrics, and other fibrous blends incorporate one or more fire retardant and heat resistant strands comprising oxidized polyacrylonitrile and one or more strengthening filaments such as metallic filaments (e.g., stainless steel), high strength ceramic filaments, or high strength polymer filaments. Such yarns, fabrics, and other fibrous blends have a superior tensile strength, cut resistance, abrasion resistance, LOI, TPP and continuous operating temperature compared to conventional fire retardant fabrics. The yarns, fabrics, and other fibrous blends are also more soft, supple, breathable and moisture absorbent and are therefore more comfortable to wear, compared to conventional fire retardant fabrics. The inventive yarns may be woven, knitted or otherwise assembled into a desired fabric or other article of manufacture.

Abstract: Fire retardant and heat resistant yarns, fabrics, and other fibrous blends incorporate one or more fire retardant and heat resistant strands comprising oxidized polyacrylonitrile and one or more strengthening filaments such as metallic filaments (e.g., stainless steel), high strength ceramic filaments, or high strength polymer filaments. Such yarns, fabrics, and other fibrous blends have a superior tensile strength, cut resistance, abrasion resistance, LOI, TPP and continuous operating temperature compared to conventional fire retardant fabrics. The yarns, fabrics, and other fibrous blends are also more soft, supple, breathable and moisture absorbent and are therefore more comfortable to wear, compared to conventional fire retardant fabrics. The inventive yarns may be woven, knitted or otherwise assembled into a desired fabric or other article of manufacture.

Abstract: Fire retardant and heat resistant yarns, fabrics, felts and other fibrous blends which incorporate high amounts of oxidized polyacrylonitrile fibers. Such yarns, fabrics, felts and other fibrous blends have a superior LOI, TPP and continuous operating temperature compared to conventional fire retardant fabrics. The yarns, fabrics, felts and other fibrous blends are also more soft and supple, and are therefore more comfortable to wear, compared to conventional fire retardant fabrics. The yarns, fabrics, felts and other fibrous blends incorporate up to 99.9% oxidized polyacrylonitrile fibers, together with at least one additional fiber, such as p-aramid, in order to provide increased tensile strength and abrasion resistance of the inventive yarns, fabrics, felts and other fibrous blends. The yarns may be woven, knitted or otherwise assembled into a desired fabric.

Abstract: Fire retardant and heat resistant yarns, fabrics, felts and other fibrous blends which incorporate high amounts of oxidized polyacrylonitrile fibers. Such yarns, fabrics, felts and other fibrous blends have a superior LOI, TPP and continuous operating temperature, compared to conventional fire retardant fabrics. The yarns, fabrics, felts and other fibrous: blends are also more soft and supple, and are therefore more comfortable to wear, compared to conventional fire retardant fabrics. The yarns, fabrics, felts and other fibrous blends incorporate up to 99.9% oxidized polyacrylonitrile fibers, together with at least one additional fiber, such as p-aramid, in order to provide increased tensile strength and abrasion resistance of the inventive yarns, fabrics, felts and other fibrous blends. The yarns may be woven, knitted or otherwise assembled into a desired fabric.

Abstract: An improved method for producing composite structures is disclosed. In accordance with the method, a first computer representation of the manner in which a plurality of plies are to be cut from a common fibrous material is provided and the representation used to cut the plies from the common material. A second computer representation of the manner in which the plurality of plies are combined to form the composite structure is used to control an ink-jet marking system to sequentially mark a partial composite with the location of a ply. After the partial composite is marked, the ply is manually placed and its placement inspected. The partial composite is then marked, using the ink-jet marking gantry, with the location of the next ply.

Abstract: Improvements in manufacturing composite material articles. The use of male molds in forming such articles has the problem of requiring large tolerances for the outer dimensions of the articles. The use of female molds has the problem of inaccurate forming of highly contoured inner surfaces. The invention produces an accurately formed inner surface by molding material against a male mold, and outer dimensions within close tolerances by curing the material in a female mold. A male caul (34) is positioned on a male mold (30). A preplied stack (32) of composite material is supported on a blanket (36) and held in position against caul (34) with caul (34) and mold (30) in an inverted position. Stack (32) is heated. A vacuum causes blanket (36) to mold stack (32) against caul (34). Mold (30) is rotated 180.degree., and stack (32) is allowed to cool. A female mold surface (43) is placed into contact with formed stack (32). Male mold (30) is moved away, leaving caul (34 ) and formed stack (32) in female mold (42).