A method of manufacturing a cured composite structure includes placing a radius filler element into a radius cavity extending along a length of a composite base member. The radius filler element is formed of a permeable material. The method also includes absorbing resin from the composite base member into the permeable material of the radius filler element. The method additionally includes curing or solidifying the resin in the radius filler element and in the composite base member to form a cured composite structure in which the resin bonds the radius filler element to the composite base member.

A method of manufacturing a cured composite structure includes placing a radius filler element into a radius cavity extending along a length of a composite base member formed of dry fiber material comprised of reinforcing fibers. The radius filler element is formed of a radius filler material. The method also includes infusing resin into the dry fiber material, and chemically reacting the resin with the radius filler material to create a mixture of resin and radius filler material along side surface interfaces between the radius filler element and the composite base member. The method additionally includes curing or solidifying the resin, and allowing solvent in the resin to evaporate causing hardening of the mixture and bonding of the radius filler element to the composite base member, and resulting in a cured composite structure.

A method of manufacturing a cured composite structure includes inserting a plurality of radius filler segments into a radius cavity extending along a length of an uncured composite base member to form an uncured structural assembly. The plurality of radius filler segments are placed in end-to-end arrangement within the radius cavity and each having opposing segment ends and being formed of a thermoplastic material. The method additionally includes heating the structural assembly at least to a base member cure temperature that causes the segment ends of end-to-end pairs of the plurality of radius filler segments to fuse together and form a continuous radius filler element that extends along the length of the composite base member. The method also includes allowing the structural assembly to cure to form a cured composite structure.

A floor panel for installation in an aircraft includes a plurality of thermoplastic C-shaped stringers, a consolidated thermoplastic deltoid filler, a thermoplastic upper facing sheet, and a thermoplastic lower facing sheet. The stringers are disposed in a parallel arrangement with one another. The deltoid filler is disposed within a longitudinally-extending notch defined by a pair of adjacent stringers. The upper facing sheet covers an upper surface of the stringers and the deltoid filler. The lower facing sheet covers a lower surface of the stringers and the deltoid filler. The stringers, the deltoid filler, and the upper and lower facing sheets are integrally consolidated forming a unitary construction.

A method of assembly for a gas turbine engine according to an example of the present disclosure includes, among other things, positioning an array of airfoils about an outer periphery of a hub, the hub being rotatable about an engine longitudinal axis of a gas turbine engine, the hub including a plurality of flanges, and each one of the airfoils including an airfoil section extending from a root section. An array of platforms are positioned about the outer periphery of the hub, each of the platforms including one or more slots defined by a plurality of platform flanges, and including the one or more slots receiving a respective one of the flanges of the hub. A plurality of retention pins are moved relative to the array of airfoils such each one of the retention pins extends through the flanges of the hub and through the plurality of platform flanges of a respective one of the platforms to mechanically attach a respective one of the platforms and the root section of a respective one of the airfoils to the hub. At least one of the airfoils and the platforms includes a plurality of composite layers that define an internal cavity, and includes a lattice structure in the internal cavity that extends between the plurality of composite layers.

A method of making a joint for a structure comprises forming a thermoplastic filler, applying an uncured first thermoset layer into direct contact with the thermoplastic filler, applying an uncured second thermoset layer into direct contact with the thermoplastic filler, and applying an uncured third thermoset layer into direct contact with the thermoplastic filler. The method additionally comprises curing the uncured first thermoset layer, the uncured second thermoset layer, and the uncured third thermoset layer at a temperature below a melting temperature of the thermoplastic material to form a cured first thermoset layer, a cured second thermoset layer, and a cured third thermoset layer and bonding together the cured first thermoset layer, the cured second thermoset layer, the cured third thermoset layer, and the thermoplastic filler.

Systems and methods are provided for fabricating gap fillers for composite parts. One exemplary system includes a controller that acquires a geometry for a gap filler that will occupy a volume at a joint between laminates of curable constituent material, subdivides the geometry of the gap filler into layers, and for each layer: identifies variations in width of the layer along a length of the gap filler, and generates instructions for trimming a web of curable constituent material to match the variations in width of the layer. The system also includes rollers that dispense webs of the curable constituent material, trimmers that trim the webs of the curable constituent material based on the instructions, and compaction rollers that compact the trimmed webs together to fabricate the gap filler.

A method and apparatus is presented. A layer of composite material is laid up on a forming tool. A bend is formed in the layer on the forming tool to form a bent layer. A laminate stack and the bent layer are assembled to form the composite filler.

A die assembly for forming a composite gap filler, including a first die having a first portion which extends along a first central axis of the first die and has a first curved surface which has a radius which changes as the first curved surface extends about the first central axis. A second die a second portion which extends along a second central axis of the second die and has a second curved surface which has a radius which changes as the second curved surface extends about the second central axis. A third die defines a third wall member which extends about the third die and which changes in width dimension wherein with the first die abutting the second die and with the third wall member abutting the first and second dies, a closed gap is formed.

Radius fillers for composite structures and composite structures that include radius fillers are disclosed herein. The radius fillers include a plurality of lengths of composite tape. Each of the plurality of lengths of composite tape includes a respective plurality of lengths of reinforcing fibers and a resin material. The plurality of lengths of reinforcing fibers in each of the plurality of lengths of composite tape defines a fiber axis direction. Each of the plurality of lengths of composite tape defines a respective fiber axis direction that is based, at least in part, on material properties of a transition region defined by a plurality of plies of composite material that defines an elongate void space within which the radius filler is configured to extend. The composite structures include the radius fillers.