Abstract: A foil journal bearing, having: a shaft; a top foil surrounding the shaft in a circumferential direction; a corrugated bump foil surrounding the top foil in the circumferential direction, wherein the corrugated bump foil includes a plurality of adjacent corrugations that each include sidewalls that extend from a radial inner end to a radial outer end of the corrugated bump foil; and a bearing sleeve surrounding the corrugated bump foil, wherein: at least one of the sidewalls of at least one of the corrugations includes an undulation disposed between the outer and inner radial ends of the sidewall; and the undulation is defined by an undulation outer end and an undulation inner end.

Abstract: An aircraft drive shaft that includes an outer shaft with a first diameter that is configured to couple a first gearbox and a second gearbox to provide power transfer between the two gearboxes. An inner shaft that is concentric with the outer shaft and has a second diameter that is configured to provide structural support to the outer shaft. A gap is located between an outer peripheral surface of the inner shaft and an inner peripheral surface of the outer shaft. The gap has a size from the outer peripheral surface to the inner peripheral surface that is at least as large as a largest ballistic projectile cross-section size that the aircraft is expected to encounter on an upcoming mission. A sleeve is located at least at a first end of the outer shaft and connects the outer shaft to the inner shaft.

Abstract: In accordance with at least one aspect of this disclosure, a composite structure can be formed of or including a plurality of composite strips. The plurality of composite strips include one or more filler strips which can have at least one filler edge having a filler edge geometry between a first surface and second surface, the second surface being opposite the first surface. The filler edge geometry can be configured to prevent formation of one or more gaps between one or more adjacent composite strips.

Abstract: A joint for use with a composite laminated component is disclosed herein. The joint includes a component including a partial U-shaped trapezoidal cavity and a triangular component. The partial trapezoidal component includes a base extending in a first direction, a first side extending away from the base at a first angle from the first direction, a second side extending away from the base at a second angle from the first direction and toward the first side, and an opening defined by the first side and the second side. The triangular component is coupled to the base and extending orthogonally away from the base in a second direction and toward the opening.

Abstract: A testing device includes a first member to be positioned on one surface of a part to be tested. A second member to be positioned on an opposed surface of the part to be tested. One of the first and second members have an ultrasonic transmitter and the other has an ultrasonic receiver. At least one of the first and second members have at least one magnetic element and the other of the first and second member have at least one magnetic or at least one ferromagnetic metallic element such that when one of the first and second members moves along the surface of the tested part the other of the first and second members will move along an opposed surface with the one of the members.

Abstract: A drive shaft has a tubular portion extending between axial ends and is hollow. There are deformations on the tubular portions. The deformations extend for a circumferential extent that is less than 180° about a central axis of the tubular portion.

Abstract: A drive shaft for transferring torque including a tubular insert extending along an axis and defining a first layer of the drive shaft including at least one straight portion and at least one undulation, wherein the tubular insert includes a first material having a first deformation temperature, and a polymeric tubular covering defining a second layer of the drive shaft surrounding the tubular insert including a second material having a deformation temperature lower than the deformation temperature of the first material, wherein the covering includes at least one straight portion adjacent to the straight portion of the tubular insert and at least one undulation adjacent to the at least one undulation of the tubular insert.

Abstract: In accordance with at least one aspect of this disclosure, a composite shaft comprises a plurality of composite elements arranged about an axis to form a hollow cylindrical shaft extending along the axis between a first end of the shaft and a second end of the shaft. The plurality of composite elements incudes: a first group of the composite elements aligned parallel to the axis, a second group of the composite elements arranged about the axis offset by an angle ? relative to the first group in a first direction, a third group of the composite elements arranged about the axis offset by an angle ? relative to the first group in a second direction opposite the first direction, wherein the third group is offset from the second group by an angle 2?, and a fourth group of the composite elements arranged about the axis offset by an angle ?.

Abstract: A flexible coupling includes a first flange having an outer edge, a first surface, a second surface opposite the first surface, and a first plurality of passages. A second flange including an outer edge section, a first surface section, a second surface section opposite the first surface section, and a second plurality of passages. A connecting element extends between and connecting the first flange and the second flange through one of the first plurality of passages and one of the second plurality passages. The connecting element includes a connecting member having a first stop element and a second stop element. A compliant component is arranged on the connecting element. The compliant component is positioned on the connecting member between one of: the first stop element and the first surface; the second stop element and the second surface section; and between the second surface and the first surface section.

Abstract: In accordance with at least one aspect of this disclosure, a system (e.g., for aircraft systems) includes an actuator cylinder. The actuator cylinder comprises, a composite cylinder body, the composite cylinder body being axi-symmetric across at least a longitudinal axis. In embodiments, the composite cylinder body can include, a first plurality of plies laid in a first direction relative to the longitudinal axis and second plurality of plies laid in a second direction relative to the longitudinal axis different from the first direction to form a hollow chamber. The actuator cylinder can include a first metallic reinforcing ring and a second metallic reinforcing ring disposed at respective axial ends of the cylinder body configured to anchor the first plurality of plies and provide an axial reaction under axial stress and configured to provide load transfer from the cylinder body to one or more adjacent actuator components.

Abstract: A drive shaft for an aircraft according to an example of the present disclosure includes, among other things, an elongated core extending between a pair of opposed couplings, an energy absorption layer made of a composite comprising metal, the energy absorption layer disposed on the core, and a first composite ballistic layer disposed along a length of the core.

Abstract: A frame for an opto-mechanical support structure includes an interconnected lattice of frame composite rods defined about an interior space with interstices defined between the frame composite rods. A method of making an opto-mechanical frame includes forming a frame of interconnected lattice of frame composite rods using one or more Automated Fiber Placement (AFP) around a mandrel. The method includes removing the mandrel from an interior space of the frame after forming the frame.

Abstract: In accordance with at least one aspect of this disclosure, a composite structure can be formed of or including a plurality of composite strips. The plurality of composite strips include one or more filler strips which can have at least one filler edge having a filler edge geometry between a first surface and second surface, the second surface being opposite the first surface. The filler edge geometry can be configured to prevent formation of one or more gaps between one or more adjacent composite strips.

Abstract: A method of forming a degassing system includes the step of forming a bundle of hollow tube membrane members by wrapping hollow tube membrane members to form the bundle at a temperature above 100° F. (38° C.). Another method of forming a degassing system includes the step of the inserting bundle into an outer canister at a temperature above 100° F. (38° C.). A fuel supply system made by these methods is also disclosed.

Abstract: A mechanical system for an aerospace application includes a drive input connected to a first axial end of a first diaphragm member, and a drive output connected to a second axial end of a second diaphragm member. The drive output is an aerospace component. The first and second diaphragm members are formed with two axial ends and at least one undulation extending radially of the axial ends. The at least one undulation is intermediate the ends. A tubular portion connects the first and second diaphragm members. The first and second diaphragm members and the tubular member are formed of fiber reinforced polymer matrix composites. The first and second diaphragm members are connected to axial ends of the tubular member by welding of the axial ends of the tubular portion to one of the inner ends of each of said first and second diaphragm members. The aerospace component is a propeller.

Abstract: Composite shafts and methods of making the same are described. The composite shafts include a plurality of composite elements arranged about an axis. The composite elements include first and second groups arranged at offset angles ±?. The groups of composite elements are configured to cooperate to allow the shaft to be flexible under bending and/or axial load and stiff under rotational load. The hollow shaft includes one or more axisymmetric radially-outward undulating portions and one or more axisymmetric narrow portions. The composite elements of groups are connected together in the radial direction along the narrow portions and the composite elements of the groups are not connected together in the radial direction along the undulating portions.

Abstract: In accordance with at least one aspect of this disclosure, a fastener free joining system, includes, a first tubular shell-type component having a first plurality of teeth defined in a first free end, each tooth extending along a respective tooth axis oblique to an axis of the first component by an angle ?. The first plurality of teeth is configured to engage with a plurality of complimentary teeth defined in a second free end of a second tubular shell-type component, such that, when engaged, the first plurality of teeth is configured to remain engaged with the plurality of complimentary teeth under axial load.

Abstract: A drive shaft which includes a first tube body having one or more first body channels defined through a wall thickness thereof. The one or more channels are configured to increase bending and/or axial flexibility of the first tube body while only allowing for a less than proportional reduction in torsional stiffness of the first tube body. A second tube body can be concentrically disposed relative to the first tube body and connected to the first tube body at a first end portion and a second end portion. The second tube body can include one or more second body channels defined through a wall thickness thereof. The one or more channels are configured to increase bending and/or axial flexibility of the second tube body while only allowing for a less than proportional reduction in torsional stiffness of the second tube body.

Abstract: A metallic coupling for a drive shaft includes a first cylindrical flange extending axially along a center axis and a second cylindrical flange extending axially along the center axis and spaced axially from the first cylindrical flange. The metallic coupling also includes a first plurality and a second plurality of connectors. Each connector of the first plurality of connectors extends from the first cylindrical flange to the second cylindrical flange and are spaced circumferentially apart from each other about the center axis. Each connector of the second plurality of connectors also extends from the first cylindrical flange to the second cylindrical flange and are spaced circumferentially apart from each other about the center axis. The second plurality of connectors are radially inward from the first plurality of connectors relative to the center axis. An annular gap is radially between the first plurality of connectors and the second plurality of connectors.

Abstract: A method for joining composite rods with tubular shape without expensive, machined connectors and without compromising the structural integrity of the composite rod includes internal and external collars applied to the ends of the composite rod and deformed via unidirectional compressive load applied by a clamp in the radial direction of the composite rod cross-section. The resulting plastic deformation of the metal collars and composite rod interlock those components to support both compressive and tensile loads. The deformed metal collars are easily joinable to other components via off-the-shelf hardware.