Abstract: Composite laminates used in structural applications include an interlayer of soft material that provides damping action to reduce noise and vibration. The interlayer may comprise a viscoelastic material which deforms under stress caused by shock, noise or vibration. A reinforcement may be embedded in the viscoelastic material to maintain the mechanical strength and stiffness of the laminate. The reinforcement may include individual or woven fibers or ridged tubes that provide the interlayer with stiffness.

Abstract: Composite laminates used in structural applications include an interlayer of soft material that provides damping action to reduce noise and vibration. The interlayer may comprise a viscoelastic material which deforms under stress caused by shock, noise or vibration. A reinforcement may be embedded in the viscoelastic material to maintain the mechanical strength and stiffness of the laminate. The reinforcement may include individual or woven fibers or ridged tubes that provide the interlayer with stiffness.

Abstract: A damped composite structure is formed from a matrix material and a plurality of shape memory alloy wire fibers held in the material matrix for damping the structure. The wire fibers may be embedded in a viscoelastic interlayer to increase damping of the structure. The wire fibers may be interspersed with reinforcement such as carbon fibers, in tows or in a mesh of fibers. The wire fibers have an inherent material loss factor greater than approximately 0.10, and may be formed from superelastic metal alloys, such as Ni—Ti, Cu—Zn—Al, Cu—Al—Ni, OR Cu—Al—Be.

Abstract: A damped composite structure is formed from a matrix material and a plurality of shape memory alloy wire fibers held in the material matrix for damping the structure. The wire fibers may be embedded in a viscoelastic interlayer to increase damping of the structure. The wire fibers may be interspersed with reinforcement such as carbon fibers, in tows or in a mesh of fibers. The wire fibers have an inherent material loss factor greater than approximately 0.10, and may be formed from superelastic metal alloys, such as Ni—Ti, Cu—Zn—Al, Cu—Al—Ni, OR Cu—Al—Be.

Abstract: Systems and methods for reducing noise in aircraft fuselages and other structures are described herein. A noise reduction system configured in accordance with one embodiment of the invention includes an auxetic core, a damping layer, and a constraining layer. In this embodiment, the auxetic core is supported by a structural member, and the damping layer is sandwiched between the auxetic core and the constraining layer. A method for manufacturing a structural assembly in accordance with another embodiment of the invention includes forming a stiffener by positioning a first ply of composite material against a first tool surface, positioning damping material against the first ply, and positioning a second ply of composite material against the damping material to sandwich the damping material between the first and second plies.

Abstract: Systems and methods for reducing noise in aircraft fuselages and other structures are described herein. A noise reduction system configured in accordance with one embodiment of the invention includes an auxetic core, a damping layer, and a constraining layer. A method for manufacturing a structural assembly in accordance with another embodiment of the invention includes forming a stiffener by positioning a first ply of composite material against a first tool surface, positioning damping material against the first ply, and positioning a second ply of composite material against the damping material to sandwich the damping material between the first and second plies. The method can further include forming a skin by positioning a third ply of composite material against a second tool surface offset from the first tool surface, and attaching the stiffener to the skin by co-curing the first, second and third plies of composite material.

Abstract: Systems and methods for reducing noise in aircraft fuselages and other structures are described herein. A noise reduction system configured in accordance with one embodiment of the invention includes an auxetic core, a damping layer, and a constraining layer. A method for manufacturing a structural assembly in accordance with another embodiment of the invention includes forming a stiffener by positioning a first ply of composite material against a first tool surface, positioning damping material against the first ply, and positioning a second ply of composite material against the damping material to sandwich the damping material between the first and second plies. The method can further include forming a skin by positioning a third ply of composite material against a second tool surface offset from the first tool surface, and attaching the stiffener to the skin by co-curing the first, second and third plies of composite material.

Abstract: Systems and methods for reducing noise in aircraft fuselages and other structures are described herein. A noise reduction system configured in accordance with one embodiment of the invention includes an auxetic core, a damping layer, and a constraining layer. In this embodiment, the auxetic core is supported by a structural member, and the damping layer is sandwiched between the auxetic core and the constraining layer. A method for manufacturing a structural assembly in accordance with another embodiment of the invention includes forming a stiffener by positioning a first ply of composite material against a first tool surface, positioning damping material against the first ply, and positioning a second ply of composite material against the damping material to sandwich the damping material between the first and second plies.

Abstract: Systems and methods for reducing noise in aircraft fuselages and other structures are described herein. A noise reduction system configured in accordance with one embodiment of the invention includes an auxetic core, a damping layer, and a constraining layer. In this embodiment, the auxetic core is supported by a structural member, and the damping layer is sandwiched between the auxetic core and the constraining layer. A method for manufacturing a structural assembly in accordance with another embodiment of the invention includes forming a stiffener by positioning a first ply of composite material against a first tool surface, positioning damping material against the first ply, and positioning a second ply of composite material against the damping material to sandwich the damping material between the first and second plies.

Abstract: Systems and methods for reducing noise in aircraft fuselages and other structures are described herein. A noise reduction system configured in accordance with one embodiment of the invention includes an auxetic core, a damping layer, and a constraining layer. In this embodiment, the auxetic core is supported by a structural member, and the damping layer is sandwiched between the auxetic core and the constraining layer. A method for manufacturing a structural assembly in accordance with another embodiment of the invention includes forming a stiffener by positioning a first ply of composite material against a first tool surface, positioning damping material against the first ply, and positioning a second ply of composite material against the damping material to sandwich the damping material between the first and second plies.

Abstract: A damped composite structure is formed from a matrix material and a plurality of shape memory alloy wire fibers held in the material matrix for damping the structure. The wire fibers may be embedded in a viscoelastic interlayer to increase damping of the structure. The wire fibers may be interspersed with reinforcement such as carbon fibers, in tows or in a mesh of fibers. The wire fibers have an inherent material loss factor greater than approximately 0.10, and may be formed from superelastic metal alloys, such as Ni—Ti, Cu—Zn—Al, Cu—Al—Ni, OR Cu—Al—Be.

Abstract: Composite laminates used in structural applications include an interlayer of soft material that provides damping action to reduce noise and vibration. The interlayer may comprise a viscoelastic material which deforms under stress caused by shock, noise or vibration. A reinforcement may be embedded in the viscoelastic material to maintain the mechanical strength and stiffness of the laminate. The reinforcement may include individual or woven fibers or ridged tubes that provide the interlayer with stiffness.

Abstract: In accordance with the present invention an aircraft floor panel is provided comprising a honeycomb core element having an upper core surface, a lower core surface, and a core thickness. An upper face sheet assembly is mounted to and seals the upper core surface and includes at least one upper material sheet impregnated with an upper epoxy resin. A lower damping face sheet assembly is mounted to and seals the lower core surface and includes at least one lower material sheet infused with a highly damped lower epoxy resin. The lower damping face sheet assembly dampens vibrational noise.

Abstract: A composite laminate structure formed from at least one high-strength, high-stiffness fiber-resin composite structural lamina laminated to at least one fiber-resin composite damping lamina, wherein the resin matrix of the structural lamina resides below its glassification temperature (Tg) and wherein the resin matrix of the damping lamina resides above its glassification temperature during normal use temperatures, thereby providing a high-strength laminate with improved damping properties.