Abstract: The present disclosure provides a co-bonded acoustic liner, including a honeycomb core with cells therein, a thermoset-based plastic septa material co-bonded to a top face of the honeycomb core; a facesheet with perforations to enable airflow, co-bonded to the thermoset-based plastic septa material; and an optional backside skin positioned under the honeycomb core, co-bonded to the bottom face of the honeycomb core, wherein the liner supports a single degree of freedom acoustic structure. The disclosure further provides methods of preparing and using such co-bonded acoustic liners.

Abstract: Certain embodiments of the present disclosure provide an acoustic inlet barrel of an engine. The acoustic inlet barrel may include an inner barrel configured to provide a boundary for directing airflow through the engine. The inner barrel may include an inner face sheet separated from an outer face sheet by an acoustic core. The inner barrel may include a plurality of elongated, non-circular perforations formed through the inner face sheet.

Abstract: A co-curable thermoset acoustic liner and method of forming the same includes a sound attenuating core having a plurality of core cells. An inner face sheet having a plurality of face sheet apertures is coupled to the core by an inner thermoset adhesive sheet, which has a plurality of adhesive sheet apertures. Each of the plurality of adhesive sheet apertures is aligned within a corresponding one of the plurality of face sheet apertures so that the plurality of core cells are placed in fluid communication with airflow over the inner face sheet to create a Single Degree of Freedom (SDOF) acoustic liner.

Abstract: A drilling system includes a single robotic drilling unit having a drill end effector positioned inside a barrel section configured as a composite sandwich structure having an inner face sheet. The robotic drilling unit is operable to drill a plurality of perforations into the inner face sheet using the drill end effector. The robotic drilling unit is configured to index a hole pattern of the perforations to one or more cell walls of a honeycomb core of the composite sandwich structure. The robotic drilling unit is configured to form the hole pattern in the inner face sheet such that the perforations are located at a spaced distance from the cell walls of the honeycomb core.

Abstract: The present disclosure provides a co-bonded acoustic liner, including a honeycomb core with cells therein, a thermoset-based plastic septa material co-bonded to a top face of the honeycomb core; a facesheet with perforations to enable airflow, co-bonded to the thermoset-based plastic septa material; and an optional backside skin positioned under the honeycomb core, co-bonded to the bottom face of the honeycomb core, wherein the liner supports a single degree of freedom acoustic structure. The disclosure further provides methods of preparing and using such co-bonded acoustic liners.

Abstract: A co-curable thermoset acoustic liner and method of forming the same includes a sound attenuating core having a plurality of core cells. An inner face sheet having a plurality of face sheet apertures is coupled to the core by an inner thermoset adhesive sheet, which has a plurality of adhesive sheet apertures. Each of the plurality of adhesive sheet apertures is aligned within a corresponding one of the plurality of face sheet apertures so that the plurality of core cells are placed in fluid communication with airflow over the inner face sheet to create a Single Degree of Freedom (SDOF) acoustic liner.

Abstract: A sandwich acoustic liner assembly includes a honeycomb core and a thermoplastic fabric sheet positioned in overlying relationship and structurally bonded with the honeycomb core. Further included is a method for fabricating a sandwich acoustic liner assembly which includes the steps of positioning a thermoplastic fabric sheet in overlying relationship with a honeycomb core and bonding structurally the thermoplastic fabric sheet to the honeycomb core.

Abstract: Certain embodiments of the present disclosure provide an acoustic inlet barrel of an engine. The acoustic inlet barrel may include an inner barrel configured to provide a boundary for directing airflow through the engine. The inner barrel may include an inner face sheet separated from an outer face sheet by an acoustic core. The inner barrel may include a plurality of elongated, non-circular perforations formed through the inner face sheet.

Abstract: A sandwich acoustic liner assembly includes a honeycomb core and a thermoplastic fabric sheet positioned in overlying relationship and structurally bonded with the honeycomb core. Further included is a method for fabricating a sandwich acoustic liner assembly which includes the steps of positioning a thermoplastic fabric sheet in overlying relationship with a honeycomb core and bonding structurally the thermoplastic fabric sheet to the honeycomb core.

Abstract: A drilling system includes a single robotic drilling unit having a drill end effector positioned inside a barrel section configured as a composite sandwich structure having an inner face sheet. The robotic drilling unit is operable to drill a plurality of perforations into the inner face sheet using the drill end effector. The robotic drilling unit is configured to index a hole pattern of the perforations to one or more cell walls of a honeycomb core of the composite sandwich structure. The robotic drilling unit is configured to form the hole pattern in the inner face sheet such that the perforations are located at a spaced distance from the cell walls of the honeycomb core.

Abstract: A drilling system may include a plurality of robotic drilling units. Each one of the robotic drilling units may include a drill end effector positioned inside a barrel section. The barrel section may be configured as a composite sandwich structure having an inner face sheet. The robotic drilling units maybe operable in synchronized movement with one another to drill a plurality of perforations into the inner face sheet using the drill end effectors in a manner providing a predetermined percent-open-area of the inner face sheet.

Abstract: A drilling system may include a plurality of robotic drilling units. Each one of the robotic drilling units may include a drill end effector positioned inside a barrel section. The barrel section may be configured as a composite sandwich structure having an inner face sheet. The robotic drilling units maybe operable in synchronized movement with one another to drill a plurality of perforations into the inner face sheet using the drill end effectors in a manner providing a predetermined percent-open-area of the inner face sheet.

Abstract: A drilling system may include a plurality of robotic drilling units. Each one of the robotic drilling units may include a drill end effector positioned inside a barrel section. The barrel section may be configured as a composite sandwich structure having an inner face sheet. The robotic drilling units maybe operable in synchronized movement with one another to drill a plurality of perforations into the inner face sheet using the drill end effectors in a manner providing a predetermined percent-open-area of the inner face sheet.

Abstract: Certain embodiments of the present disclosure provide an acoustic inlet barrel of an engine. The acoustic inlet barrel may include an inner barrel configured to provide a boundary for directing airflow through the engine. The inner barrel may include an inner face sheet separated from an outer face sheet by an acoustic core. The inner barrel may include a plurality of elongated, non-circular perforations formed through the inner face sheet.

Abstract: A method of fabricating a composite part comprises generating a partial vacuum between a ply material and a form, advancing the partial vacuum and the ply material along the form, sensing an edge of a previously applied course of the ply material and cutting a profile on the ply material in response to the sensed edge.

Abstract: A system to fabricate a composite item includes an end effector, robotic vehicle, sensor, and cutting system. The end effector applies a course to a layup form. The robotic vehicle positions the end effector. The sensor senses an edge of a previously applied course. The cutting system cuts a profile on the course in response to the sensed edge.

Abstract: A method of fabricating a composite part comprises generating a partial vacuum between a ply material and a form, advancing the partial vacuum and the ply material along the form, sensing an edge of a previously applied course of the ply material and cutting a profile on the ply material in response to the sensed edge.

Abstract: To apply a plurality of courses on a layup form to fabricate a composite item, a first course of the plurality of courses is applied on the layup form along a first path. A second path is determined that overlaps an edge of the first course by a predetermined minimum overlap distance. The edge is sensed. A profile is cut along a second course of the plurality of courses to correspond to the sensed edge. The second course is applied on the layup form along the second path.

Abstract: A device for placing a ply on a substrate surface includes a vacuum manifold assembly configured for attachment to a vacuum source and a substrate seal configured to provide a substantially gas impermeable interface with the substrate surface. This device further includes a ply seal configured to provide a substantially gas impermeable interface with the ply. In this manner, vacuum applied to the vacuum manifold assembly depressurizes an area between the ply and the substrate surface.

Abstract: A device for placing a ply on a substrate surface includes a vacuum manifold assembly configured for attachment to a vacuum source and a substrate seal configured to provide a substantially gas impermeable interface with the substrate surface. This device further includes a ply seal configured to provide a substantially gas impermeable interface with the ply. In this manner, vacuum applied to the vacuum manifold assembly depressurizes an area between the ply and the substrate surface.