A method for joining two substantially planar fiber-composite structural components, includes stacking the two components on a support jig to overlap along a joining region. A lower component end section within the joining region borders a gap between the upper component and the jig, where the upper component is unsupported by the jig. The gap is bordered on an opposite side of the lower component end section by a filling portion of the upper component or a planar filler element supported by the jig. The lower component is joined to the upper component within the joining region by applying temperature and pressure to the components. A width of the gap allows the upper component to elastically deform along the gap under the pressure and bend down into the gap to abut the jig along the gap and thereby compensate thickness tolerances between the components during the pressure application.

A bonded joint for use in bonding composite materials is provided and includes a composite rib having electrically conductive properties and a composite structure having electrically conductive properties. An electrically conductive preform is provided that facilitates a bond between the composite rib and the composite structure. A mesh composition that bonds the composite rib to the preform and that bonds the preform to the composite structure is provided and is electrically conductive to conduct current between the composite rib and the composite structure.

A system for fusing thermoplastic composite structures includes a skin and a substructure on an inner surface of the skin. The system also includes a shaping surface of a tool, with the skin laid up on the shaping surface. The shaping surface is configured to maintain the shape of an outer mold line. The system further includes at least one insulation layer applied over a flange of the substructure and over exposed portions of the inner surface of the skin not in contact with the substructure, and a vacuum bag at least partly enclosing the skin and the substructure. Heat can be applied to the shaping surface to fuse the substructure to the skin such that the skin exceeds its melting point and at least a portion of a raised segment of the substructure does not exceed its melting point.

Embodiments are directed to systems and methods for two or more cured composite assemblies that are bonded together to form a tubular composite structure, wherein each of the cured composite assemblies do not have a tubular shape. The tubular composite structure may form a spar for an aerodynamic component, for example. The two or more cured composite assemblies may comprise carbon or fiberglass composite materials or a combination of materials. Each of the cured composite assemblies may further comprise axial edges that are configured to be bonded to another of the cured composite assemblies, wherein the axial edges have a sloped shape. An adhesive agent may be applied on the axial edges for bonding two cured composite assemblies. Alternatively, or additionally, one or more fasteners may be used to attach the axial edges of at least two cured composite assemblies.

The invention provides a sonotrode (100) for welding a material, the sonotrode (100) comprising a welding section (110) configured for contacting the material, wherein the welding section (110) defines a rounded shape (111) in a cross-section parallel to a longitudinal axis (A) of the sonotrode (100), wherein the rounded shape (111) approximates a circular sector (20), wherein the circular sector (20) has a central angle α.sub.c selected from the range of 25°-300°, and wherein the circular sector (20) has a central radius r.sub.c selected from the range of 5-30 mm, and wherein the sonotrode (100) has a width W perpendicular to the longitudinal axis (A) [and to the cross-section], wherein W is selected from the range of 10-100 mm.

A joining method and assembly for an aircraft. To improve the characteristics or permit hitherto impossible connections between thermoplastic and thermoset components, a multi-material joining method is disclosed in which a thermoplastic connecting region is formed on the thermoplastic component. The connecting region is connected to the thermoset component by interdiffusion. For this purpose, the uncured second component is brought into contact with the connecting region and heat is supplied. An interdiffusion layer is formed which fixedly connects the second component and the connecting region to one another and thus joins the first component to the second component.

A composite assembly with a laminate of fibre plies impregnated with a laminate matrix material is disclosed having pad of fibre plies impregnated with a pad matrix material, and a part with a body with protrusions which extend from the body and penetrate at least some of the fibre plies of the pad. The pad is bonded to the laminate by a stepped lap joint or a scarf joint. The assembly is manufactured by pressing the protrusions into the pad, and after the protrusions have been pressed into the pad, curing a pad matrix material impregnating the pad, and bonding the pad to the laminate.

A portable welding device comprising: a base facing a work surface, designed to receive tapes in electrically conductive composite materials to be joined or defined by at least one already positioned tape; an operating head receiving one tape at a time and movable with respect to the base along at least a first movement line parallel to the work surface; a motorized arm connecting the operating head to the base and selectively activatable to impart movements to the operating head; and feeding means selectively activatable to feed one tape at a time to the operating head and connected to the operating head; the operating head comprises a positioning roller receiving a tape at a time; a pressure roller spaced from and aligned with the positioning roller along the first movement line; and an inductor interposed between the positioning roller and the pressure roller with reference to the first movement line.

A bonded composite joint includes a first carbon fiber-reinforced polymer (CFRP) panel; a second CFRP panel; a corrugated structure placed between the first and second CFRP panels; and an adhesive placed between the first and second CFRP panels and in contact with the corrugated structure. The corrugated structure has a shape defined by a given wavelength λ.

A system for consolidating materials, comprising a sonotrode configured to direct ultrasonic energy into materials to be consolidated, wherein the materials to be consolidated have both a glass transition temperature and a melting temperature; a non-rigid consolidating material in proximity to the sonotrode, wherein the non-rigid consolidating material and sonotrode define a region therebetween for receiving the materials to be consolidated, and wherein the non-rigid consolidating material has a glass transition temperature that is higher than the glass transition temperature of the materials to be consolidated and a melting temperature that is higher than the melting temperature of the materials to be consolidated.