Abstract: A method of offset load testing a tubular composite specimen with two pairs of aligned holes and having at least one defect, the method comprising: providing a testing apparatus having a pair of arms including a fixed arm and a mobile arm; securing the pair of arms using a fastener assembly in each of the two pairs of aligned holes; and moving the mobile arm to impart an offset load force to the tubular specimen. One aspect includes a method of offset load testing comprising: providing a testing apparatus having a pair of arms including a fixed arm and a mobile arm; providing a tubular composite specimen with a top portion and a bottom portion; securing the pair of arms to the top and bottom portions of the tubular composite specimen; and moving the mobile arm to impart an offset load force to the tubular composite specimen.

Abstract: A composite yoke includes a plurality of packs of unidirectional plies and at least one pack of chopped fibers disposed between two adjacent packs of unidirectional plies. A method of manufacturing a composite yoke includes arranging a plurality of plies of unidirectional fibers to form a first pack of unidirectional plies, arranging a layer of chopped fibers on the first pack of unidirectional plies, arranging a plurality of plies of unidirectional fibers on to form a second pack of unidirectional plies on the layer of chopped fibers, curing the composite yoke to form a cured composite yoke, and cutting excess material from the first pack of unidirectional plies, the layer of chopped fibers, and the second pack of unidirectional plies to form a plurality of arms.

Abstract: In an aspect, there is a method of determining allowable defects for a composite component comprising identifying at least one wrinkle characteristic of a composite component wrinkle defect; making a first plurality of specimens each having a predetermined wrinkle defect representative of the composite component wrinkle defect; measuring each of the predetermined wrinkle defects in the first plurality of specimens for at least one performance metric to generate performance data; and generating an allowable wrinkle defect profile based on the performance data from the first plurality of specimens. In other aspects, there are methods of making a specimen with a predetermined wrinkle defect.

Abstract: A tiltrotor controls shield having a blade or wire substructure under a fragile spinner fairing improves bird strike durability. The present disclosure discloses a spinner wind fairing with a shield structure disposed thereunder for providing protection to the proprotor assembly components. The shield structure can segment a projectile, such as a bird, that penetrates the spinner fairing into a series of smaller and lower energy elements spread across a wider area, such that the rotor components can withstand the impact of the smaller elements without damage.

Abstract: A light weight hybrid torque transfer joint trunnion has an integral metal hub spline fitting oriented on a center axis. This integral metal hub spline fitting may be made of steel, aluminum, titanium, or the like and may be generally cylindrical. The integral metal hub spline fitting defines an integral central internally-splined mast or driveshaft coupling opening centered about the center axis. A composite material body centrally retains, and is cured to, the metal hub spline fitting. Torque transfer joint link attachment pins extend from the composite material body and are rigidly linked to the metal hub spline fitting. In an example constant-velocity joint, a plurality of pivoting linkages may each be rotatably coupled to the torque transfer joint link attachment pins, and each of the plurality of pivoting linkages may, in turn be secured to a rotor yoke configured to mount a plurality of rotorcraft blades.

Abstract: A method of offset load testing a tubular composite specimen with two pairs of aligned holes and having at least one defect, the method comprising: providing a testing apparatus having a pair of arms including a fixed arm and a mobile arm; securing the pair of arms using a fastener assembly in each of the two pairs of aligned holes; and moving the mobile arm to impart an offset load force to the tubular specimen. One aspect includes a method of offset load testing comprising: providing a testing apparatus having a pair of arms including a fixed arm and a mobile arm; providing a tubular composite specimen with a top portion and a bottom portion; securing the pair of arms to the top and bottom portions of the tubular composite specimen; and moving the mobile arm to impart an offset load force to the tubular composite specimen.

Abstract: In an aspect, there is a method of determining allowable defects for a composite component comprising identifying at least one wrinkle characteristic of a composite component wrinkle defect; making a first plurality of specimens each having a predetermined wrinkle defect representative of the composite component wrinkle defect; measuring each of the predetermined wrinkle defects in the first plurality of specimens for at least one performance metric to generate performance data; and generating an allowable wrinkle defect profile based on the performance data from the first plurality of specimens. In other aspects, there are methods of making a specimen with a predetermined wrinkle defect.

Abstract: A tiltrotor controls shield having a blade or wire substructure under a fragile spinner fairing improves bird strike durability. The present disclosure discloses a spinner wind fairing with a shield structure disposed thereunder for providing protection to the proprotor assembly components. The shield structure can segment a projectile, such as a bird, that penetrates the spinner fairing into a series of smaller and lower energy elements spread across a wider area, such that the rotor components can withstand the impact of the smaller elements without damage.

Abstract: An ice-management method for an aircraft includes scavenging torque from a mast of the aircraft with a system that is configured to provide an ice-management capability. The method includes using the scavenged torque to impart a vibratory force to an arm of the system and imparting the vibratory force from the arm to an inner surface of a spinner of the aircraft via a contact of the arm.

Abstract: In a first aspect, there is a method of making a specimen with a predetermined wrinkle defect, the steps including orienting a composite material around a layup tool at a wrap angle to form a closed loop; and generating at least one wrinkle with a predetermined characteristic in a portion of the closed loop to form a specimen. The predetermined characteristic is at least one of the following: wrinkle location, an outward wrinkle, an inward wrinkle, a wrinkle width, a wrinkle height, and a wrinkle length. In another aspect, there is a method of determining allowable defects for a composite component.

Abstract: There is a method of making a tubular specimen with a predetermined wrinkle defect including providing a layup tool with a cavity forming member having a cavity which resembles a desired shape of the at least one wrinkle; orienting a composite material around the mandrel at a wrap angle to form a closed loop; positioning a wrinkle tool on the closed loop; and/or generating at least one wrinkle with a predetermined characteristic in a portion of the closed loop to form a tubular specimen. The predetermined characteristic is at least one of the following: wrinkle location, an outward wrinkle, an inward wrinkle, a wrinkle width, a wrinkle height, and a wrinkle length. In another aspect, there is a method of offset load testing a tubular composite specimen. In a third aspect, there is a method of determining allowable defects for a composite component.

Abstract: A power supply is described having a current measurement circuit connected between a supply voltage terminal and an output voltage terminal of the power supply. The current measurement circuit comprises a set of two or more sense resistors in a parallel configuration, first and second ones of the sense resistors having different impedances. Switching circuitry is provided, which is responsive to a control signal to connect one or more of the sense resistors between the supply voltage terminal and the output voltage terminal. A controller is operable to generate the control signal in dependence on a measured current level across the set of sense resistors. In this way, by switching the resistors in and out of the circuit, the voltage drop across the measurement circuit can be kept to a desired range.

Abstract: A composite yoke includes a plurality of packs of unidirectional plies and at least one pack of chopped fibers disposed between two adjacent packs of unidirectional plies. A method of manufacturing a composite yoke includes arranging a plurality of plies of unidirectional fibers to form a first pack of unidirectional plies, arranging a layer of chopped fibers on the first pack of unidirectional plies, arranging a plurality of plies of unidirectional fibers on to form a second pack of unidirectional plies on the layer of chopped fibers, curing the composite yoke to form a cured composite yoke, and cutting excess material from the first pack of unidirectional plies, the layer of chopped fibers, and the second pack of unidirectional plies to form a plurality of arms.

Abstract: An ice-management method for an aircraft includes scavenging torque from a mast of the aircraft with a system that is configured to provide an ice-management capability. The method includes using the scavenged torque to impart a vibratory force to an arm of the system and imparting the vibratory force from the arm to an inner surface of a spinner of the aircraft via a contact of the arm.

Abstract: A light weight hybrid torque transfer joint trunnion has an integral metal hub spline fitting oriented on a center axis. This integral metal hub spline fitting may be made of steel, aluminum, titanium, or the like and may be generally cylindrical. The integral metal hub spline fitting defines an integral central internally-splined mast or driveshaft coupling opening centered about the center axis. A composite material body centrally retains, and is cured to, the metal hub spline fitting. Torque transfer joint link attachment pins extend from the composite material body and are rigidly linked to the metal hub spline fitting. In an example constant-velocity joint, a plurality of pivoting linkages may each be rotatably coupled to the torque transfer joint link attachment pins, and each of the plurality of pivoting linkages may, in turn be secured to a rotor yoke configured to mount a plurality of rotorcraft blades.

Abstract: A system comprising a cryogenic engine system and a refrigeration system, wherein the cryogenic engine system and the refrigeration system are mechanically and/or thermally coupled with each other. The refrigeration system is driven by the cryogenic engine system and the cryogenic engine system enhances cooling of the refrigeration system.

Abstract: The present invention provides a method of operating an engine (14) having one or more cylinders (16) each having a piston (18) within the cylinder (16) and each piston (18) having an expansion stroke and a return stroke and a top dead center (TDC) position and a bottom dead center position (BDC) and said engine (14) employing a working fluid (WF) and a heat exchange fluid (HEF), comprising the steps of: introducing the HEF during the return stroke of the engine; introducing the working fluid (WF) during the expansion stroke of the engine; causing the exhaust valve to be opened at or near bottom dead center of the piston BDC; delivering the HEF to the cylinder (16) after the exhaust valve has been opened; and closing the exhaust valve before TDC, such as to allow the working fluid to be compressed by the piston within the cylinder. The invention also provides an engine (14) capable of being operated in accordance with the method.

Abstract: The present invention provides a method of operating an engine (14) having one or more cylinders (16) each having a piston (18) within the cylinder (16) and each piston (18) having an expansion stroke and a return stroke and a top dead centre (TDC) position and a bottom dead centre position (BDC) and said engine (14) employing a working fluid (WF) and a heat exchange fluid (HEF), comprising the steps of: introducing the HEF during the return stroke of the engine; introducing the working fluid (WF) during the expansion stroke of the engine; causing the exhaust valve to be opened at or near bottom dead centre of the piston BDC; delivering the HEF to the cylinder (16) after the exhaust valve has been opened; and closing the exhaust valve before TDC, such as to allow the working fluid to be compressed by the piston within the cylinder. The invention also provides an engine (14) capable of being operated in accordance with the method.

Abstract: In a first aspect, there is a method of making a specimen with a predetermined wrinkle defect, the steps including orienting a composite material around a layup tool at a wrap angle to form a closed loop; and generating at least one wrinkle with a predetermined characteristic in a portion of the closed loop to form a specimen. The predetermined characteristic is at least one of the following: wrinkle location, an outward wrinkle, an inward wrinkle, a wrinkle width, a wrinkle height, and a wrinkle length. In another aspect, there is a method of determining allowable defects for a composite component.

Abstract: There is a method of making a tubular specimen with a predetermined wrinkle defect including providing a layup tool with a cavity forming member having a cavity which resembles a desired shape of the at least one wrinkle; orienting a composite material around the mandrel at a wrap angle to form a closed loop; positioning a wrinkle tool on the closed loop; and/or generating at least one wrinkle with a predetermined characteristic in a portion of the closed loop to form a tubular specimen. The predetermined characteristic is at least one of the following: wrinkle location, an outward wrinkle, an inward wrinkle, a wrinkle width, a wrinkle height, and a wrinkle length. In another aspect, there is a method of offset load testing a tubular composite specimen. In a third aspect, there is a method of determining allowable defects for a composite component.