Abstract: An in-situ fiber-optic temperature field measurement is disclosed that can allow process monitoring and diagnosis for thermoplastic composite welding and other applications. A distributed fiber-optic sensor can be permanently embedded in a thermoplastic welded structure when it is welded and left there to perform lifelong monitoring and inspection. The fiber optic sensor can include a dissolvable coating, or a coating matched to the composite material to be welded. Other applications include in-situ fiber-optic temperature field measurement on thermoset composite curing (autoclave), for thermoplastic and thermoset composites during compression molding, and for fiber-optic field measurements on freeze/thaw of large items of public health interest, such as stored or transported foodstuffs.

Abstract: A welding assembly is disclosed. The welding assembly includes a plurality of separately controllable actuators (e.g., pneumatic, having an axially movable ram) to press a corresponding portion of a first workpiece (e.g., a discrete flange of a first stiffener) against a second workpiece (e.g., an outer skin) for welding operations (e.g., via induction welding).

Abstract: An induction welding assembly and inductive welding method is disclosed. A tooling block includes a workpiece zone, a conductive heat generation and transfer member, and a heat shield, with the conductive heat generation and transfer member being disposed between the workpiece zone and the heat shield. A first workpiece and a second workpiece may be disposed within the workpiece zone such that the first workpiece is disposed between the conductive heat generation and transfer member and the second workpiece. The heat shield, conductive heat generation and transfer member, first workpiece, and second workpiece may be pressed together. An induction coil may be positioned in spaced relation to the heat shield and may be operated to heat the conductive heat generation and transfer member. Heat is conductively transferred by the conductive heat transfer member to the first workpiece to weld the first workpiece and the second workpiece together.

Abstract: Methods and apparatus' for induction welding a first workpiece to a second workpiece at a welding region may include a metallic strip. The metallic strip may be a mesh. The properties of the metallic strip, such as, for example, pore size, thickness, and density, may be configured to conduct heat uniformly across the welding region and prevent eddy current formation across a workpiece. The metallic strip may be embedded in a workpiece or may be fixed to an induction welding tool that acts on the welding region during induction welding. A removable polymer tape may be disposed between a workpiece and a metallic strip fixed to an induction welding tool. The workpieces may be thermoplastic composite structures and thermoplastic composite stiffeners in aircraft structures.

Abstract: A welding assembly is disclosed. The welding assembly includes a plurality of separately controllable actuators (e.g., pneumatic, having an axially movable ram) to press a corresponding portion of a first workpiece (e.g., a discrete flange of a first stiffener) against a second workpiece (e.g., an outer skin) for welding operations (e.g., via induction welding).

Abstract: During a manufacturing method, an induction welder is provided that includes a concentrator and a coil extending through a receptacle in the concentrator. The receptacle projects into the concentrator from a face surface of the concentrator. A first thermoplastic body arranged with a second thermoplastic body are provided. The first thermoplastic body is located next to the face surface. The first thermoplastic body is induction welded to the second thermoplastic body to provide a weld seam between the first thermoplastic body and the second thermoplastic body. The concentrator extends along a portion of the weld seam. The induction welding includes: generating an electromagnetic field with the coil; and concentrating a portion of the electromagnetic field with the concentrator onto a region of the first thermoplastic body.

Abstract: A method of forming a weld joint is provided. A first component having a base portion and a flange extending from the base portion is provided. A second component is provided. The second component and the flange are brought into abutment and a load is applied to the flange via the second component. The flange is biased against the second component by a reaction of the first component to the load. One of the first and the second components is vibrated to form a weld joint between at least a part of the second component and at least a part of the flange.

Abstract: An assembly is provided for induction welding. This assembly utilizes a plurality of heat shields (e.g., mica heat shields) that are aligned/disposed in end-to-end relation, with each such heat shield having a recess. An induction welding coil may be disposed within a heat shield recess during induction welding operations and is movable along a welding path while proceeding along the recesses of the various heat shields. This welding path may be axially extending or may be curved. The induction welding assembly may be used to induction weld a stiffener to a curved skin or shell, for instance where a base of the recess for each heat shield is curved such that the induction welding coil may be moved along a curved welding path and while maintaining a constant spacing between the induction welding coil and the recess base of the various heat shields.

Abstract: An assembly is provided for induction welding. This assembly utilizes a heat shield (e.g., a mica heat shield) with a recess. An induction welding coil may be disposed within this heat shield recess during induction welding operations. The wall thickness of the heat shield within the recess may be reduced to enhance heat transfer to a workpiece during induction welding operations. The heat shield may be coated with a ceramic coating to enhance the heat shield's heat resistance and reduce heat shield flaking at the recess during induction welding operations.

Abstract: 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.

Abstract: A method is provided for joining thermoplastic components. During this method, a skin is provided that is configured from or otherwise includes a skin fiber-reinforced thermoplastic composite. A support member is provided that is configured from or otherwise includes a support member fiber-reinforced thermoplastic composite. A shim is arranged at an interface between the skin and the support member. The shim is configured from or otherwise includes a shim fiber-reinforced thermoplastic composite. The support member is welded to the skin through the shim at the interface.

Abstract: A tacking device may comprise: a handle; a main body extending from a first end of the handle to a second end of the handle; and a plurality of soldering irons, each soldering iron in the plurality of soldering irons extending from a first side of the main body through the main body to a second side of the main body, each soldering iron in the plurality of soldering irons including a piercing end disposed on the second side of the main body.

Abstract: 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.

Abstract: An assembly is provided for induction welding. This induction welding assembly includes a fixture. The fixture includes a first support structure and a second support structure. The second support structure includes a frame and a plurality of trunks. Each of the trunks is connected to and repositionable on the frame. The fixture is configured to secure a workpiece vertically between the first support structure and the second support structure using the trunks during induction welding of the workpiece.

Abstract: A method for forming a fiber-reinforced thermoplastic part may comprise the steps of locating a lightning strike protection layer on a mold surface of a mold tool, locating a thermoplastic layer over the mold tool, heating the thermoplastic layer to a pliable forming temperature, conforming the thermoplastic layer to a mold surface of the mold tool, and depositing a plurality of fiber strips over the thermoplastic layer.

Abstract: A method for forming a fiber reinforced thermoplastic part may comprise the steps of locating a thermoplastic material over a mold tool, heating the thermoplastic material to a pliable forming temperature, conforming the thermoplastic material to a mold surface of the mold tool, and depositing a plurality of fiber strips over the thermoplastic material.

Abstract: A composite fiber for use in additive manufacturing such as fused filament fabrication is described along with methods of its construction and use. The composite fiber includes a single continuous fiber (e.g., a continuous carbon roving) and a polymer (e.g., a high glass transition polymer) in intimate contact. The composite fiber is formed through immersion of the continuous fiber in a series of two or more solutions that together include monomer(s), catalysts, or other materials for generating the polymer as the continuous fiber moves through the solutions.

Abstract: During a manufacturing method, an induction welder is provided that includes a concentrator and a coil. The concentrator includes a receptacle and a face surface. The receptacle projects vertically into the concentrator from the face surface to an end of the receptacle. The receptacle extends laterally within the concentrator between opposing sides of the receptacle. The receptacle extends longitudinally within the concentrator along a centerline. The coil is seated and extends longitudinally along the centerline within the receptacle. A first thermoplastic body arranged with a second thermoplastic body are provided. The first thermoplastic body is located vertically next to the face surface. The first thermoplastic body is induction welded to the second thermoplastic body. The induction welding includes: generating an electromagnetic field with the coil; and concentrating the electromagnetic field with the concentrator onto a region of the first thermoplastic body.

Abstract: Methods and apparatus' for induction welding a first workpiece to a second workpiece at a welding region may include a metallic strip. The metallic strip may be a mesh. The properties of the metallic strip, such as, for example, pore size, thickness, and density, may be configured to conduct heat uniformly across the welding region and prevent eddy current formation across a workpiece. The metallic strip may be embedded in a workpiece or may be fixed to an induction welding tool that acts on the welding region during induction welding. A removable polymer tape may be disposed between a workpiece and a metallic strip fixed to an induction welding tool. The workpieces may be thermoplastic composite structures and thermoplastic composite stiffeners in aircraft structures.

Abstract: A method of repairing a defect of a thermoplastic component is provided. The thermoplastic component has a thermoplastic material at the defect having a first melting temperature, and the defect has a contact surface (TC contact surface). The method includes a) providing a patch comprising a second thermoplastic material having a second melting temperature that is below the first melting temperature. The patch includes a contact surface (TP contact surface); b) disposing a portion of a heating element between the TC contact surface and the TP contact surface. The heating element is operable to heat up as a result of electrical resistance; c) forcing the TP surface toward the TC surface; and d) inputting energy into the heating element to cause the heating element to heat and maintain the TP surface at or above the second melting temperature to produce bonding between the thermoplastic component and the patch.