A thermoplastic composite structure is produced by consolidating and forming a composite preform to a desired shape. The preform comprises plies of a high melt temperature thermoplastic prepreg that are tacked together by a low melt temperature thermoplastic adhering the plies together in fixed registration.

A method for welding at least two parts including a thermoplastic material and having respective surfaces to be welded, including: inserting an insert between the surfaces to be welded of the two parts; generating heat via the insert; wherein the insert moves in relation to the parts to be welded in a welding direction. Also, an installation adapted for implementation of this method.

Described herein are stringer assemblies, such as blade stringers, and methods of forming thereof. A stringer assembly comprises a first fabric composite stiffener, a second fabric composite stiffener, and an intermediate tape composite stiffener, disposed between and connected to each of the first and second stiffeners. Using three separate components allows forming sharp bends, eliminating voids and gap fillers, and adding new features, such as edge reinforcements. Each of the first and second fabric composite stiffeners comprises a web portion, a flange portion, and a curved portion, positioned between the web and flange portions. The web portions surround and are attached to the intermediate tape composite stiffener and, in some examples, include tapered-out edges for additional rigidity. The flange portions are attached to the composite base. The curved portions conform to the flared-out edges of the intermediate tape composite stiffener, which extends and connects to the composite base.

A thermoplastic product includes a fabric-based reinforcing sheet and a polymerized thermoplastic material. The fabric-based reinforcing sheet is wound about a mandrel to form a plurality of layers having a cross-sectional shape that corresponds to the mandrel. The fabric-based reinforcing sheet includes a plurality of fiber bundles, which may have a bidirectional orientation or configuration. A polymerized thermoplastic material is disposed within each layer of the fabric-based reinforcing sheet. The polymerized thermoplastic material bonds each layer of the fabric-based reinforcing sheet to an adjacent layer.

A hollow punch rivet is described having a flange and a rivet section. Furthermore, a method for the attachment of individual components to one another using a punch rivet is described, with at least one of the components being formed by a material of the composite material. The method includes the following steps: a) arrangement of the die button against one of the two components to be secured to one another, which are placed on one another, wherein the die button has a bore which is dimensioned to receive the rivet section, b) carrying out a relative movement of the punch rivet with the free end of the rivet section to the fore towards the components arranged on one another and in the direction of the die button, c) piercing of the components with the free end of the rivet section and introduction of the rivet section into the bore of the die button until the component contact surface comes into contact and the component adjacent to the flange, d) using a plunger in order to dilate the punch rivet at least locally and e) forming a rivet bead by reshaping the free end region of the rivet section.

Disclosed is a method of resistance welding between composite articles. A conductive element is provided between faying surfaces, having a plurality of lower resistivity electrode portions spaced apart along the length of the contact area between the composite articles. The electrode portions can be used to spot weld across the electrode portions, and along a longitudinal portion of the conductive element between the electrode portions by application of an electrical current. Also disclosed are apparatus for use in the resistance welding methods and composite articles and structures and elements incorporating the conductive element.

A first member formed of a thermoplastic resin molding mixed with a fiber material and a second member formed of a molding containing at least a thermoplastic resin are welded by friction stir spot welding using a double-acting tool for friction stir spot welding. An overlapping part between the first member and the second member is formed, and the tool is disposed against the overlapping part while the pin and the shoulder are rotated about the rotation axis. The pin is plunged into the overlapping part, and friction stir is performed to cause extension fibers to remain around a plunging region of the pin while the shoulder is retracted to release an overflow material. The shoulder is brought closer to the overlapping part to wrap the extension fibers into the overflow material when the overflow material is backfilled while the pin is retracted from the overlapping part.

A Z-pin for increasing a delamination resistance of continuous fibre-reinforced polymer composites, formed of a composite material including a polymer matrix, and a plurality of fibres embedded in the polymer matrix and aligned along the length direction of Z-pin, the fibres having an elongation at break of at least 2% and a tensile strength of at least 5 GPa, the polymer matrix having an elongation at break equal to or greater than the elongation at break of the fibres, and a tensile strength of at least 120 MPa.

A method for forming a fiber-reinforced thermoplastic hollow structure may comprise: abutting a first surface of a first flange of a shell and a second surface of a second flange of the shell with a mating component; disposing an end block laterally adjacent to the shell; applying a first load to a sidewall of the shell; applying a second load to the second flange of the shell; and vibrating one of the shell or the mating component while keeping a non-vibrating component stationary, the non-vibrating component including one of the shell or the mating component.

An induction welding system includes a first gantry, a second gantry, and a support structure. The first gantry includes a first frame and a first plurality of trunks. The first plurality of trunks defines a first curved inner support surface of the first gantry. The first curved inner support surface has a first curvature geometry. The second gantry includes a second frame and a second plurality of trunks. The second plurality of trunks defines a second curved inner support surface of the second gantry. The second curved inner support surface has a second curvature geometry which is different than the first curvature geometry. The support structure includes at least one tooling member defining a curved outer support surface of the support structure. The support structure is longitudinally moveable relative to the first gantry and the second gantry.