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 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 method for joining two objects by anchoring an insert portion provided on one of the objects in an opening provided on the other one of the objects. The anchorage is achieved by liquefaction of a thermoplastic material and interpenetration of the liquefied material and a penetrable material, the two materials being arranged on opposite surfaces of the insert portion and the wall of the opening. Before such liquefaction and interpenetration, an interference fit is established in which such opposite surfaces are pressed against each other, and, for the anchoring, mechanical vibration energy and possibly a shearing force are applied, wherein the shearing force puts a shear stress on the interference fit.

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.

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.

There is provided a method for producing a metal-resin composite which includes a resin member and a metal member having a roughened surface in at least a portion of the surface thereof, the resin member being joined so as to be in contact with at least a portion of the roughened surface. The method includes a step of joining the resin member and the metal member by melting the resin member with the frictional heat generated in the surface of the metal member on its side opposite to the resin member in a state where the metal member and the resin member are superposed. The method includes making adjustment so that when the roughened surface is measured at arbitrary five points by using a confocal microscope according to ISO 25178, the developed area ratio (Sdr) is 5 or more in terms of number-average value.

There is provided a method for producing a metal-resin composite which includes a resin member and a metal member having a roughened surface in at least a portion of the surface thereof, the resin member being joined so as to be in contact with at least a portion of the roughened surface. The method includes a step of joining the resin member and the metal member by melting the resin member with the frictional heat generated in the surface of the metal member on its side opposite to the resin member in a state where the metal member and the resin member are superposed. The method includes making adjustment so that when the roughened surface is measured at arbitrary five points by using a confocal microscope according to ISO 25178, the developed area ratio (Sdr) is 5 or more in terms of number-average value.

The invention relates a process for the preparation of a bonded structure (4) comprising at least a first plastic part (1) having a first bonding surface (1a), said process comprising the step of a) treating at least part of a first bonding surface of said first plastic part with a flame of a propane-comprising gas, said propane-comprising gas being propane or a mixture comprising at least 50 wt. % of propane based on the weight of the propane-comprising gas with one or more gases selected from the group consisting of methane, ethane, butane, pentane, and hexane, wherein, during treatment with a flame of the propane-comprising gas, a flame is produced by burning a mixture of air and the propane-comprising gas, wherein the gas-to-air ratio is chosen such that the propane gas to oxygen volume ratio is equal to or less than 1:5.01, for example less than 1:5.00 and preferably at least 3.50 to obtain a first plastic part having a flame-treated first bonding surface.

The invention relates a process for the preparation of a bonded structure (4) comprising at least a first plastic part (1) having a first bonding surface (1a), said process comprising the step of a) treating at least part of a first bonding surface of said first plastic part with a flame of a propane-comprising gas, said propane-comprising gas being propane or a mixture comprising at least 50 wt. % of propane based on the weight of the propane-comprising gas with one or more gases selected from the group consisting of methane, ethane, butane, pentane, and hexane, wherein, during treatment with a flame of the propane-comprising gas, a flame is produced by burning a mixture of air and the propane-comprising gas, wherein the gas-to-air ratio is chosen such that the propane gas to oxygen volume ratio is equal to or less than 1:5.01, for example less than 1:5.00 and preferably at least 3.50 to obtain a first plastic part having a flame-treated first bonding surface.