Abstract: Compositions including a polyamide, and compaction rollers for an automated fiber placement machine incorporating the composition are provided. The polyamide may be a reaction product of at least one diamine and an aromatic dicarboxylic acid, a hydroxy benzoic acid, or their respective ester or acyl halide derivatives. The at least one diamine may include an amino terminated perfluorinated alkyl ether polymer or oligomer. The composition may have a thermal conductivity of from about 0.2 to about 50 Watts per meter Kelvin (Wm?1K?1).

Abstract: Compositions including a polyimide and one or more thermally conductive fillers, and compaction rollers for an automated fiber placement machine incorporating the compositions are provided. The polyimide may be a polymeric reaction product of a dianhydride and one or more diamines. The one or more diamines may include a fluorine-containing alkyl ether diamine. The one or more thermally conductive fillers may include one or more of a carbon-based filler, boron nitride, a metal, or combinations thereof. The compositions may have a thermal conductivity of from about 0.2 to about 50 Watts per meter Kelvin (Wm?1 K?1).

Abstract: Compositions including a poly(arylene ether), and compaction rollers for an automated fiber placement machine incorporating the composition are provided. The poly(arylene ether) may be a reaction product of at least one disubstituted benzophenone and at least one polyol. The at least one polyol may include at least one fluorinated diol. The composition may have a thermal conductivity of from about 0.2 to about 50 Watts per meter Kelvin (Wm?1K?1).

Abstract: There is provided a method that includes directing one or more infrared cameras at a compaction roller of a composite laying head of a composite layup machine. The one or more infrared cameras are mounted aft of the compaction roller. The method includes applying heat to a substrate by a heater. The heater is mounted forward of the compaction roller. The method further includes using the one or more infrared cameras, to obtain one or more infrared images of the compaction roller, during laying down of one or more composite tows of a composite layup onto the substrate by the compaction roller. The method further includes identifying, based on the one or more infrared images, one or more temperature profiles of the compaction roller, and analyzing identified temperature profiles, to determine one or more of, a layup quality of the composite layup, and a heat history of the composite layup.

Abstract: There is provided a method that includes directing one or more infrared cameras at a compaction roller of a composite laying head of a composite layup machine. The one or more infrared cameras are mounted aft of the compaction roller. The method includes applying heat to a substrate by a heater. The heater is mounted forward of the compaction roller. The method further includes using the one or more infrared cameras, to obtain one or more infrared images of the compaction roller, during laying down of one or more composite tows of a composite layup onto the substrate by the compaction roller. The method further includes identifying, based on the one or more infrared images, one or more temperature profiles of the compaction roller, and analyzing identified temperature profiles, to determine one or more of, a layup quality of the composite layup, and a heat history of the composite layup.

Abstract: A method of detecting defects in a composite layup includes capturing, using an infrared camera, reference images of a reference layup being laid up by a reference layup head. The method also includes manually reviewing the reference images for defects, and generating reference defect masks indicating defects in the reference images. The method further includes training, using the reference images and reference defect masks, a neural network, creating a machine learning model that, given a production image as input, outputs a production defect mask indicating the defect location and the defect type of each defect. The method also includes capturing, using an infrared camera, production images of a production layup being laid up by the production layup head, and applying the model to the production images to automatically generate a production defect masks indicating each defect in the production images.

Abstract: Compositions including a poly(arylene ether), and compaction rollers for an automated fiber placement machine incorporating the composition are provided. The poly(arylene ether) may be a reaction product of at least one disubstituted benzophenone and at least one polyol. The at least one polyol may include at least one fluorinated diol. The composition may have a thermal conductivity of from about 0.2 to about 50 Watts per meter Kelvin (Wm?1K?1).

Abstract: Compositions including a polyamide, and compaction rollers for an automated fiber placement machine incorporating the composition are provided. The polyamide may be a reaction product of at least one diamine and an aromatic dicarboxylic acid, a hydroxy benzoic acid, or their respective ester or acyl halide derivatives. The at least one diamine may include an amino terminated perfluorinated alkyl ether polymer or oligomer. The composition may have a thermal conductivity of from about 0.2 to about 50 Watts per meter Kelvin (Wm?1K?1).

Abstract: Compositions including a polyimide and one or more thermally conductive fillers, and compaction rollers for an automated fiber placement machine incorporating the compositions are provided. The polyimide may be a polymeric reaction product of a dianhydride and one or more diamines. The one or more diamines may include a fluorine-containing alkyl ether diamine. The one or more thermally conductive fillers may include one or more of a carbon-based filler, boron nitride, a metal, or combinations thereof. The compositions may have a thermal conductivity of from about 0.2 to about 50 Watts per meter Kelvin (Wm?1 K?1).

Abstract: An automated fiber-placement method comprises delivering a first quantity of pulsed energy to first discrete portions of at least one fiber-reinforced tape strip, and delivering a second quantity of pulsed energy to second discrete portions of at least the one fiber-reinforced tape strip, alternating with the first discrete portions. The first quantity of pulsed energy heats the first discrete portions to a first temperature. The second quantity of pulsed energy heats the second discrete portions to a second temperature. The automated fiber-placement method further comprises laying down at least the one fiber-reinforced tape strip against a substrate along a virtual curvilinear path, such that (i) at least the one fiber-reinforced tape strip is centered on the virtual curvilinear path, and (ii) the first discrete portions are transformed into discrete tape-regions, geometrically different from the first discrete portions.

Abstract: Systems and methods are provided for dynamically managing heater position for an Automated Fiber Placement (AFP) machine. One embodiment is a method that includes retrieving distance data indicating predicted distances of a heating surface of a heater of the AFP machine to a surface of a laminate being laid-up by the AFP machine, for each of multiple locations along a path. The method also includes directing the AFP machine to lay up the laminate in accordance with a Numerical Control (NC) program, identifying a current location of the heater in the path, determining a speed at which the heater of the AFP machine is moving, correlating the current location of the heater with a predicted distance, and adjusting an amount of power for the heater at the current location based on the predicted distance that was correlated with the current location, and the speed at the current location.

Abstract: Closed-loop systems and methods for controlling the temperature at the compaction point as an automated fiber placement (AFP) machine is placing material over complex surface features at varying speeds. The closed-loop system starts with multiple infrared temperature sensors directed at the layup surface in front of the compaction roller and also at the new layup surface behind the compaction roller. These sensors supply direct temperature readings to a control computer, which also receives speed data and a listing of active tows from the AFP machine and is also programmed with the number of plies in the current layup. In accordance with one embodiment, the heater control system uses a proportional-integral-derivative loop to control the temperature at the compaction point (e.g., at the interface of the compaction roller and a newly laid tow) and regulate the heater power to achieve the desired temperature.

Abstract: An infrared camera is directed aft of a compaction roller of a composite laying head. Heat is applied to a substrate by a heater mounted forward of the compaction roller. Infrared images are captured of composite tows laid down on a substrate by the compaction roller. Whether the composite tows have sufficient contact is determined using the infrared images.

Abstract: An article of manufacture comprises a strip that extends along and is centered on a virtual curvilinear path, comprising an arc, having an arc length and a radius. A ratio of the strip-width to the radius is greater than or equal to 0.003. The arc length is equal to or greater than a product of the radius and ?/64. Within each of discrete strip-regions of the strip, one of the unidirectional reinforcement fibers that is closest to the first longitudinal strip-edge is more buckled than another one of the unidirectional reinforcement fibers that is closest to the second longitudinal strip-edge. Ones of the unidirectional reinforcement fibers that are buckled are parallel to a smallest one of virtual surfaces, joining the first longitudinal strip-edge and the second longitudinal strip-edge.

Abstract: An automated fiber-placement method comprises delivering a first quantity of pulsed energy to first portions of at least one fiber-reinforced tape strip, and delivering a second quantity of pulsed energy to second portions of at least the one fiber-reinforced tape strip, alternating with the first portions. Each one of the second portions at least partially overlaps two adjacent ones of the first portions such that overlapping regions of the first portions and the second portions have a higher temperature than non-overlapping regions of the first portions and the second portions. The automated fiber-placement method further comprises laying down at least the one fiber-reinforced tape strip against a substrate along a virtual curvilinear path, such that (i) at least the one fiber-reinforced tape strip is centered on the virtual curvilinear path, and (ii) the overlapping regions are transformed into discrete tape-regions, geometrically different from the overlapping regions.

Abstract: An automated fiber-placement method comprises delivering a first quantity of pulsed energy to first portions of at least one fiber-reinforced tape strip, and delivering a second quantity of pulsed energy to second portions of at least the one fiber-reinforced tape strip, alternating with the first portions. Each one of the second portions at least partially overlaps two adjacent ones of the first portions such that overlapping regions of the first portions and the second portions have a higher temperature than non-overlapping regions of the first portions and the second portions. The automated fiber-placement method further comprises laying down at least the one fiber-reinforced tape strip against a substrate along a virtual curvilinear path, such that (i) at least the one fiber-reinforced tape strip is centered on the virtual curvilinear path, and (ii) the overlapping regions are transformed into discrete tape-regions, geometrically different from the overlapping regions.

Abstract: An article of manufacture (200) comprises a strip (202) that extends along and is centered on a virtual curvilinear path (128), comprising an arc (156), having an arc length (154) and a radius (134). A ratio of the strip-width (208) to the radius (134) is greater than or equal to 0.003. The arc length (154) is equal to or greater than a product of the radius (134) and ?/64. Within each of discrete strip-regions (222) of the strip (202), one of the unidirectional reinforcement fibers (132) that is closest to the first longitudinal strip-edge (204) is more buckled than another one of the unidirectional reinforcement fibers (132) that is closest to the second longitudinal strip-edge (206). Ones of the unidirectional reinforcement fibers (132) that are buckled are parallel to a smallest one of virtual surfaces, joining the first longitudinal strip-edge (204) and the second longitudinal strip-edge (206).

Abstract: An automated fiber-placement method (300) comprises delivering a first quantity of pulsed energy (122) to first discrete portions (124) of at least one fiber-reinforced tape strip (104), and delivering a second quantity of pulsed energy (123) to second discrete portions (125) of at least the one fiber-reinforced tape strip (104), alternating with the first discrete portions (124). The first quantity of pulsed energy (122) heats the first discrete portions (124) to a first temperature. The second quantity of pulsed energy (123) heats the second discrete portions (125) to a second temperature.

Abstract: Closed-loop systems and methods for controlling the temperature at the compaction point as an automated fiber placement (AFP) machine is placing material over complex surface features at varying speeds. The closed-loop system starts with multiple infrared temperature sensors directed at the layup surface in front of the compaction roller and also at the new layup surface behind the compaction roller. These sensors supply direct temperature readings to a control computer, which also receives speed data and a listing of active tows from the AFP machine and is also programmed with the number of plies in the current layup. In accordance with one embodiment, the heater control system uses a proportional-integral-derivative loop to control the temperature at the compaction point (e.g., at the interface of the compaction roller and a newly laid tow) and regulate the heater power to achieve the desired temperature.

Abstract: Closed-loop systems and methods for controlling the temperature at the compaction point as an automated fiber placement (AFP) machine is placing material over complex surface features at varying speeds. The closed-loop system starts with multiple infrared temperature sensors directed at the layup surface in front of the compaction roller and also at the new layup surface behind the compaction roller. These sensors supply direct temperature readings to a control computer, which also receives speed data and a listing of active tows from the AFP machine and is also programmed with the number of plies in the current layup. In accordance with one embodiment, the heater control system uses a proportional-integral-derivative loop to control the temperature at the compaction point (e.g., at the interface of the compaction roller and a newly laid tow) and regulate the heater power to achieve the desired temperature.