A housing includes a first surrounding wall connected around a base wall. The first surrounding wall has a first joint portion opposite to the base wall, a first outer surface and a first inner surface. The first outer and inner surfaces extend from the first joint portion toward the base wall. The first joint portion is stepped and has a first projecting portion adjoining the first outer surface, and a first shoulder portion indented from the first projecting portion and proximal to the first inner surface. The first shoulder portion has a plurality of parallel spaced-apart ribs protruding therefrom in a same direction as the first projecting portion. Each of the ribs has a tip that does not extend beyond a top end of the first projecting portion.

A first aspect of the invention provides a method of joining a part to a composite component, the composite component comprising fibres impregnated with a matrix material, and the part comprising a plurality of projections, the method comprising: inserting the projections into the composite component; and pre-heating the projections before they are inserted into the composite component, so that the projections are at a higher temperature than the composite component as they are inserted into the composite component. The projections locally heat the matrix material of the composite component as they are pushed into the composite component. Increased temperature during insertion is advantageous as the reduced matrix viscosity, due to the increased temperature of the matrix, results in better consolidation of the fibres around the projections and minimises the distortion of the fibres. The composite component is only heated locally where heating is required, which removes the need to heat the entire composite component.

A method of bonding a first object to a second object includes the steps of: providing the first object including thermoplastic material in a solid state, providing the second object including a proximal surface, applying a mechanical pressing force and a mechanical excitation capable to liquefy the thermoplastic material until a flow portion of the thermoplastic material is flowable and penetrates into structures of the second object, and stopping the mechanical excitation and letting the thermoplastic material resolidify to yield a positive-fit connection between the first and the second object. The second object has a region of low density, wherein the protrusion penetrates the region of low density at least partly before the thermoplastic material is made flowable, and wherein the first object includes a protruding portion after the step of letting the thermoplastic material resolidify, the protruding portion at least partly penetrates the region of low density.

The present invention is directed to a cover arrangement for reducing the noise emitted by a motor vehicle part, in particular of the engine of a motor vehicle, comprising a cover having at least a fibrous carrier layer, and the cover arrangement comprising at least one mounting part for mounting the cover to the vehicle, the mounting part having at least one base portion made from a thermoplast, characterized in that the at least one mounting part is mounted to the cover by at least one welding connection of the at least one base portion and at least one fibrous carrier layer.

A method for connecting a surface-structured workpiece (SSW) and a plastic workpiece using a joining tool with a sonotrode. The method includes: positioning the SSW and the plastic workpiece on an anvil such that a structured contact surface section (SCSS) of the SSW faces a contact surface of the plastic workpiece; positioning the sonotrode in contact with an outer surface of the SSW that is opposite to the SCSS; and applying pressure to the sonotrode and/or the anvil perpendicular to the contact surface to hold the workpieces fixed between the anvil and the sonotrode and applying ultrasonic vibrations to the workpieces by the sonotrode for a predetermined period of time to induce softening of the plastic workpiece and penetrate pin-like elements of the SCSS into the plastic workpiece.

A method of bonding a first object to a second object includes the steps of: providing the first object including thermoplastic material in a solid state, providing the second object including a proximal surface, applying a mechanical pressing force and a mechanical excitation capable to liquefy the thermoplastic material until a flow portion of the thermoplastic material is flowable and penetrates into structures of the second object, and stopping the mechanical excitation and letting the thermoplastic material resolidify to yield a positive-fit connection between the first and the second object. The second object has a region of low density, wherein the protrusion penetrates the region of low density at least partly before the thermoplastic material is made flowable, and wherein the first object includes a protruding portion after the step of letting the thermoplastic material resolidify, the protruding portion at least partly penetrates the region of low density.

A method for producing a component with a surface that is suitable for plastic welding or adhesive bonding of two parts is provided. As a preparation step prior to joining, a filler sheet comprising a thermoplastic material or adhesive is arranged on a first surface of a first component and a structuring tool is arranged on the filler sheet. Mechanical force is applied to the structuring tool and heat is applied to the filler sheet such that the filler sheet is attached to the first surface of the first component and such that the structuring tool is partially embedded in the filler sheet. The structuring tool is subsequently removed from the filler sheet to produce a plurality of protrusions in the outer surface of the filler sheet. After surface structuring the first and second components are joined using any type of welding technique or joined using of adhesive bonding.

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 method for joining two objects by anchoring an insert portion provided on a first object in an opening provided on a second object. 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. During the step of inserting the insert portion in the opening and/or during anchorage a clamping force is applied to opposing surfaces of the second object to prevent the second object from cracking or bulging.

A fiber-reinforced plastic joined body is provided, in which a fiber-reinforced molded article (X) containing carbon fibers and a thermoplastic resin and having a joining surface (x), and a thermoplastic resin member (Y) having a joining surface (y) are welded via the joining surfaces (x) and (y) by applying ultrasonic to the molded article (X), and in which: (1) a maximum value of tan by viscoelastic measurement of the molded article (X) is less than 70% of a maximum value of tan by viscoelastic measurement of the thermoplastic resin contained in the molded article (X) within a range of a glass transition temperature 100 C. of the thermoplastic resin contained in the molded article (X), (2) at least one of the joining surfaces (x) and (y) has an energy director, and (3) an application surface of the molded article (X) to which ultrasonic sound is applied is smooth.