Abstract: An under-root fan blade spacer system including a fan hub including a fan hub receiver, the fan hub receiver having a hub receiver floor, the fan hub receiver having an opening configured to receive a fan blade root, the fan blade root includes a base end; a gap formed between the base end of the fan blade root and a hub receiver floor; and a spacer disposable within the gap, the spacer comprising a shape memory alloy material.

Abstract: A method for forming a curved acoustic liner panel includes additive manufacturing a honeycomb core that includes a plurality of walls. Each wall of the plurality of walls includes a straight base edge at a flat bottom of the honeycomb core and a corrugated top edge opposite the straight base edge. The honeycomb core is heated and placed between a first curved mold and a second curved mold. The honeycomb core is pressed between the first curved mold and the second curved mold to curve the honeycomb core and stretch the corrugated top edge of each wall of the plurality of walls such that the top edge is no longer corrugated.

Abstract: An acoustic structure includes at least a pair of adjacent panels. The panels have edges, and the panels define a plurality of cells. A first of the at least a pair of acoustic panels is connected to a second of the pair of acoustic panels at adjacent ones of the edges. There is a pair of spaced faces in each acoustic panel between which the plurality of cells extend. There are openings in each of the edges of each of the adjacent acoustic panels, and between a first of the faces and a second of the faces. A securing member extends through the openings in each of the first and the second of the adjacent acoustic panels. A gas turbine engine is also disclosed.

Abstract: An acoustic structure includes at least a pair of adjacent panels. The panels have edges, and the panels define a plurality of cells. A first of the at least a pair of acoustic panels is connected to a second of the pair of acoustic panels at adjacent ones of the edges. There is a pair of spaced faces in each acoustic panel between which the plurality of cells extend. There are openings in each of the edges of each of the adjacent acoustic panels, and between a first of the faces and a second of the faces. A securing member extends through the openings in each of the first and the second of the adjacent acoustic panels. A gas turbine engine is also disclosed.

Abstract: A method for forming a curved acoustic liner panel includes additive manufacturing a honeycomb core that includes a plurality of walls. Each wall of the plurality of walls includes a straight base edge at a flat bottom of the honeycomb core and a corrugated top edge opposite the straight base edge. The honeycomb core is heated and placed between a first curved mold and a second curved mold. The honeycomb core is pressed between the first curved mold and the second curved mold to curve the honeycomb core and stretch the corrugated top edge of each wall of the plurality of walls such that the top edge is no longer corrugated.

Abstract: Fan assemblies for gas turbine engines include a rotor disk having a plurality of lugs with a plurality of slots defined between adjacent lugs. A fan platform is configured to be mounted to a lug of the plurality of lugs, the fan platform having a forward tab and an aft tab. An aft retention ring is configured to be fixedly attached to an aft side of the rotor disk and has a platform retention hook for receiving the aft tab of the fan platform. A forward retention ring is configured to be fixedly attached to a forward side of the rotor disk, the forward retention ring having a tab hook configured to attach the forward retention ring to the lug of the plurality of lugs and retain the forward tab of the fan platform to the lug of the plurality of lugs.

Abstract: Fan assemblies for gas turbine engines include a rotor disk having a plurality of lugs with a plurality of slots defined between adjacent lugs. A fan platform is configured to be mounted to a lug of the plurality of lugs, the fan platform having a forward tab and an aft tab. An aft retention ring is configured to be fixedly attached to an aft side of the rotor disk and has a platform retention hook for receiving the aft tab of the fan platform. A forward retention ring is configured to be fixedly attached to a forward side of the rotor disk, the forward retention ring having a tab hook configured to attach the forward retention ring to the lug of the plurality of lugs and retain the forward tab of the fan platform to the lug of the plurality of lugs.