A method for welding thermoplastic components, in particular, thermoplastic fiber composite structural components for an aircraft or spacecraft, having the following steps. Arranging an insert, which has a conductor structure having a plurality of parallel electrical conductor elements, in a joining zone between a first thermoplastic component and a second thermoplastic component such that at least some portions of the parallel electrical conductor elements are located in the joining zone; locally melting the components in the region of the joining zone by supplying current to the conductor structure; disconnecting the connector elements; and removing the insert from the joining zone by pulling out the disconnected conductor elements. An insert for the resistance welding of thermoplastic components is also provided.

A method for surface preparation of a composite substrate prior to adhesive bonding. The surface preparation method includes applying a resin-containing peel ply onto a composite substrate, followed by co-curing. The resin-containing peel ply contains a non-removable textile carrier and a removable woven fabric embedded therein. After co-curing, the peel ply is removed from the composite substrate such that the removable woven fabric is removed but the non-removable textile carrier and a film of residual resin remain on the composite substrate, thereby creating a modified, bondable surface on the composite substrate. The composite substrate with the modified surface can be bonded to another composite substrate, whereby the textile carrier remains an integrated part of the final bonded structure.

To achieve universal welding of thermoplastic workpiece parts with simple equipment, an infrared light transmission welding method is disclosed in which simple polychromatic, incoherent infrared light is generated by a simple infrared light source and is directed through a first workpiece part to a weld point for the purposes of connection to a second workpiece part. In particular, the infrared light is directed through a transparent bracing element.

An example method of joining a first structure and a second structure is described that includes forming a bond cavity between a first structure and a second structure, placing a semi-permeable breather material at one or more exits of the bond cavity, placing a vacuum bag around the bond cavity and the semi-permeable breather material, evacuating the bond cavity via a vacuum port and forcing adhesive into the bond cavity via an adhesive port while the bond cavity is evacuated, and curing the adhesive via one or more heaters to bond the first structure to the second structure.

An example method of joining a first structure and a second structure is described that includes placing an adhesive within a bond cavity for bonding a first structure to a second structure, securing a vacuum bag to the first structure and the second structure so as to surround a portion of the first structure and the second structure, evacuating the bond cavity via a vacuum port to deaerate the adhesive within the bond cavity, after deaerating the adhesive, moving the first structure and the second structure relative to one another such that deaerated adhesive is disposed between the first structure and the second structure, and curing, via one or more heaters, the deaerated adhesive disposed between the first structure and the second structure to bond the first structure to the second structure.

A bonding method for bonding an adherend with a high-frequency dielectric heating adhesive sheet is provided. The adherend includes a fluorine-containing surface at least containing fluorine on a surface thereof. The high-frequency dielectric heating adhesive sheet includes a high-frequency dielectric adhesive layer including a thermoplastic resin and a dielectric filler. A surface free energy of the high-frequency dielectric adhesive layer is in a range from 15 mJ/m.sup.2 to 30 mJ/m.sup.2. A melting point of the high-frequency dielectric adhesive layer is in a range from 110 degrees C. to 300 degrees C. The bonding method includes bringing the fluorine-containing surface of the adherend into contact with the high-frequency dielectric adhesive layer and applying a high-frequency wave to the high-frequency dielectric adhesive layer to bond the high-frequency dielectric heating adhesive sheet to the fluorine-containing surface.

Described herein are techniques for reducing resin squeeze-out including a method comprising receiving a first component and a second component, where the first component is configured to be joined to the second component at an overlap area using an adhesive layer to form a structure having a ledge. The method further comprises applying the adhesive layer to the overlap area on the first component. The method further comprises selectively curing a portion of the adhesive layer adjacent to the ledge. The method further comprises forming the structure by combining the first component, the second component, and the adhesive layer and curing a remainder of the adhesive layer.

A stiffened part formed from at least two members of thermoset composite material including at least one body of a first structure and optionally a second structure. A manufacturing method includes: forming a fibre preform and impregnating each body of the first structure with thermosetting resin or forming a pre-impregnated fibre preform to obtain a body formed from uncured thermosetting composite material supported by a mandrel; optionally partially or fully polymerising at least one body supported by a mandrel; optionally, providing the second structure formed from uncured, partially uncured or fully uncured thermosetting composite material; optionally, depositing a layer of uncured thermosetting adhesive on an area where a fully cured member makes contact with another member of the part; joining the members, each member being juxtaposed with; or stacked upon, at least one other member; fully curing the assembly by heat treatment; removing the mandrel from each fully cured body.

A system and method for welding thermoplastic components by positioning and moving a heated plate between the components to melt their respective faying surfaces, and as the plate moves, pressing the components together so that the melted faying surfaces bond together as they cool and re-solidify, thereby creating a composite structure. The plate has a heated portion which is positioned between and heated to melt a portion of the first and second faying surfaces. A manipulator mechanism moves the plate along an interface from between the portion to between a series of subsequent portions of the first and second faying surfaces, thereby welding the thermoplastic components along the entire interface to create the composite structure. An injection device may also move behind the plate and reciprocally inject a polymer between the first and second faying surfaces to provide toughness and crack arresting properties.

A method of joining a non-metallic pipe to a metallic pipe. The pipe may be wrapped with one or more sheets of reinforcement material (e.g., pre-impregnated fiberglass, carbon fiber, or aramid fiber) and then fitted with an adapter or fitting that is connectable to a metallic pipe. The reinforcement material may be heated using a heating apparatus which allows the material to bond to the pipe to strengthen the joint.