METHOD FOR ASSEMBLING BY WELDING AT LEAST TWO COMPONENTS OF COMPOSITE MATERIAL AND ASSEMBLY OF COMPONENTS OF COMPOSITE MATERIAL OBTAINED IN THIS MANNER

Abstract

A method for assembling by welding at least two components of composite material includes positioning at least one connection layer of fibers so as to be interposed between the contact surfaces of the two components and/or positioned in the region of at least one contact surface of the two components, each connection layer having unidirectional fibers which are oriented in a direction different from the directions of the fibers of at least the fiber layers of the two components close to the contact surfaces. An induced electrical current is generated in a direction approximately parallel with the direction of the fibers of each connection layer. This method enables heating to be concentrated in the region of the contact surfaces. An assembly is disclosed of at least two components of composite material by carrying out the method.

Claims

1. A method for assembling by welding at least two components of composite material, the assembly comprising a first component comprising at least a first contact surface, a second component comprising at least a second contact surface and at least one interface in a region of which the first and second contact surfaces are connected, each component of composite material comprising several layers of fibers which are superimposed and embedded in a matrix, the method comprising: generating an induced electrical current, wherein the assembly method comprises a step of positioning at least one connection layer of conductive fibers to be interposed between the first contact surface of the first component and the second contact surface of the second component and/or positioned in the region of at least one contact surface of the first and second contact surfaces, each connection layer having unidirectional fibers which are oriented in a direction different from directions of the fibers of at least the fiber layers of the first and second components close to the first and second contact surfaces, and wherein the induced electrical current is generated in a direction approximately parallel with the direction of the fibers of each connection layer.

2. The method for assembling by welding at least two components of composite material according to claim 1, wherein the fibers of each connection layer are oriented in a direction different from all directions of the fibers of the fiber layers of the first and second components.

3. The method for assembling by welding at least two components of composite material according to claim 1, wherein the fibers of at least one of the connection layers are impregnated with a resin.

4. The method for assembling by welding at least two components of composite material according to claim 1, wherein the fibers of the first and second components form with a reference direction an angle in the order of 0, 45, 90 or 135 and wherein the fibers of each connection layer form an angle with the reference direction in an order of 22.5, 67.5, 112.5 or 157.5.

5. The method for assembling by welding at least two components of composite material according to claim 1, wherein a single connection layer is interposed between the first and second contact surfaces of the first and second components.

6. The method for assembling by welding at least two components of composite material according to claim 1, wherein a first connection layer is interposed between the first and second contact surfaces of the first and second components and wherein a second connection layer and/or a third connection layer is/are positioned in the region of the first contact surface of the first component and/or of the second contact surface of the second component.

7. The method for assembling by welding at least two components of composite material according to claim 1, wherein a connection layer is positioned in the region of the first contact surface of the first component and/or in the region of the second contact surface of the second component.

8. The method for assembling by welding at least two components of composite material according to claim 1, wherein at least one connection layer is positioned just before generating the induced electrical current.

9. The method for assembling by welding at least two components of composite material according to claim 1, wherein at least one connection layer which is positioned in the region of a contact surface is integrated in the component before a step of consolidating the component.

10. An assembly of at least two components of composite material obtained by carrying out the method according to claim 1.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0024] Other features and advantages will be appreciated from the following description of the disclosure herein given purely by way of non-limiting example with reference to the appended drawings, in which:

[0025] FIG. 1 is a cross-section of an assembly of two components of composite material which illustrates an embodiment of the prior art;

[0026] FIG. 2 is a perspective view of an example of an assembly of two components of composite material;

[0027] FIG. 3 is a cross-section of an assembly of two components of composite material which illustrates a first embodiment of the disclosure herein;

[0028] FIG. 4 is a cross-section of an assembly of two components of composite material which illustrates a second embodiment of the disclosure herein, prior to assembly;

[0029] FIG. 5A is a partially broken-away view of a first contact surface of a first component of the assembly which can be seen in FIG. 4;

[0030] FIG. 5B is a view of a connection layer of the assembly which can be seen in FIG. 4; and

[0031] FIG. 5C is a partially broken-away view of a second contact surface of a second component of the assembly which can be seen in FIG. 4.

DETAILED DESCRIPTION

[0032] FIGS. 2 through 4 show an assembly of two components 20 and 22 of composite material.

[0033] By way of example, as illustrated in FIG. 2, the component 20 is a reinforcement 24 with an omega-shaped cross-section and the component 22 is a panel 26.

[0034] The reinforcement 24 has a central portion 28 and first and second wings 30, 30 which are arranged at one side and the other of the central portion 28 and which are connected to the panel 26. The reinforcement 24 is delimited by lateral edges 32, 32.

[0035] Of course, the disclosure herein is not limited to this type of assembly.

[0036] Regardless of which embodiment is involved, the assembly comprises a first component 20 comprising at least a first contact surface 20.1, a second component 22 comprising at least a second contact surface 22.1 and at least one interface 34 in the region of which the first and second contact surfaces 20.1, 22.1 are connected, as illustrated in FIGS. 3 and 4.

[0037] Each component 20, 22 of composite material comprises several layers of reinforcement fibers which are superimposed and embedded in a matrix.

[0038] According to an embodiment, the reinforcement fibers are carbon fibers which are embedded in a thermoplastic resin.

[0039] For each of the layers, the fibers are unidirectional and oriented in a direction which forms a specific angle with a reference direction.

[0040] For each of the first and second components 20, 22, the number of layers and the orientation of their fibers are determined in accordance with the mechanical characteristics desired for the first and second components 20, 22. The first component 20 comprises superimposed layers, with each of the unidirectional fibers, the different layers of the first component 20 having fibers which are oriented in a first set of directions.

[0041] The second component 22 comprises superimposed layers, with each of the unidirectional fibers, the different layers of the second component 22 having fibers which are oriented in a second set of directions.

[0042] Each set comprises a plurality of directions, the fibers forming for each of the directions a specific angle with the reference direction. The first set of the first component 20 may comprise directions different from those of the second set of the second component 22.

[0043] For each set, the fibers of the first and second components 20, 22 form with the reference direction an angle in the order of 0, 45, 90 or 135.

[0044] The first and second contact surfaces 20.1, 22.1 are connected by welding by generating heating as a result of an induced electrical current.

[0045] To this end, the assembly method comprises a step of generating an induced electrical current in the region of the interface 34 using an electromagnetic field generator 36.

[0046] According to a feature of the disclosure herein, the interface 34 comprises at least one connection layer 38 of conductive fibers interposed between the first contact surface 20.1 of the first component 20 and the second contact surface 22.1 of the second component 22 and/or positioned in the region of at least one contact surface from the first and second contact surfaces 20.1, 22.1.

[0047] The term conductive fiber is intended to be understood to mean that the fibers of the connection layer 38 have the capacity to convey an electrical current and therefore to generate heating by the Joule effect.

[0048] When the interface 34 comprises several connection layers 38, these different connection layers 38 have fibers which are all oriented in the same direction. The fibers of each connection layer 38 are of the same material as the fibers of the layers of the first and second components 20, 22.

[0049] Each connection layer 38 comprises unidirectional fibers which are oriented in a direction different from the directions of the fibers of at least the layers of fibers of the first and second components 20, 22 close to the first and second contact surfaces 20.1 and 22.1. The term close is intended to be understood to mean the first ten layers of the first and second components 20, 22 from the first and second contact surfaces 20.1, 22.1.

[0050] According to a configuration, the fibers of each connection layer 38 are oriented in a direction different from all the directions of the fibers of the fiber layers of the first and second components 20, 22.

[0051] By way of example, the fibers of each connection layer 38 form an angle in the order of 22.5, 67.5, 112.5 or 157.5 with the reference direction.

[0052] The electromagnetic field generator 36 is configured to generate an induced electrical current in a direction approximately parallel with the direction of the fibers of each connection layer 38.

[0053] Consequently, taking into account the orientation of the fibers of the connection layer(s) 38 and the orientation of the induced current produced by the electromagnetic field generator 36, the heating generated by the induced current will be substantially produced in the region of the connection layer(s) 38. This arrangement enables a concentration of the heating to be obtained in the region of the interface 34. According to another advantage, this/these connection layer(s) 38 contribute(s) to the structural properties of the assembly.

[0054] According to another feature, the fibers of at least one of the connection layers 38 are impregnated with a resin.

[0055] In addition, during the welding, the first and second components 20 and 22 are subjected to compression forces which are intended to press the first and second contact surfaces 20.1, 20.2.

[0056] In this manner, during the welding, the heating will soften or deconsolidate the resin which will creep as a result of the compression forces and fill any gaps which may be present between the first and second components 20, 22. This arrangement contributes to reducing the porosity of the assembly.

[0057] According to an embodiment, the fibers of the connection layer(s) are of the same material as the fibers of the first and second components 20 and 22. According to an embodiment, the fibers of the connection layer(s) are of carbon. In this manner, in contrast to the prior art, the connection layer(s) 38 contribute(s) to the mechanical characteristics of the assembly and have a functionality post assembly.

[0058] When the fibers of the connection layer(s) 38 are impregnated with resin, they are impregnated with a thermoplastic resin of the same type as that of at least one of the first and second components 20, 22.

[0059] According to a first embodiment which can be seen in FIG. 3, the interface 34 comprises a single connection layer 38 which is interposed between the first and second contact surfaces 20.1, 22.1 of the first and second components 20 and 22.

[0060] According to another embodiment which can be seen in FIGS. 4, 5A through 5C, the interface 34 comprises a first connection layer 38 which is interposed between the first and second contact surfaces 20.1, 22.1 of the first and second components 20 and 22 (which can be seen in FIG. 5B), a second connection layer 38 which is positioned in the region of the first contact surface 20.1 of the first component 20 and a third connection layer 38 positioned in the region of the second contact surface 22.1 of the second component 22. The fibers of the different connection layers 38, 38, 38 all form an angle with the longitudinal direction.

[0061] In FIG. 5A, the first three layers of the first component 20 from the first contact surface 20.1 have been illustrated, that is to say, the second connection layer 38, a first layer 40 having fibers which are oriented in a first direction different from that of the fibers of the second connection layer 38 and a second layer 42 having fibers which are oriented in a second direction different from that of the fibers of the second connection layer 38.

[0062] In FIG. 5C, the first three layers of the second component 22 from the second contact surface 22.1 have been illustrated, that is to say, the third connection layer 38, a third layer 44 having fibers which are oriented in a third direction different from that of the fibers of the third connection layer 38 and a fourth layer 46 having fibers which are oriented in a fourth direction different from that of the fibers of the third connection layer 38.

[0063] According to another embodiment, the interface 34 comprises a first connection layer 38 which is interposed between the first and second contact surfaces 20.1, 22.1 of the first and second components 20 and 22 and a second connection layer 38 or 38 positioned only in the region of one of the two contact surfaces 20.1, 22.2.

[0064] According to another embodiment, the interface 34 does not comprise any connection layer 38 interposed between the first and second contact surfaces 20.1, 22.2 of the first and second components 20, 22. The interface 34 comprises a connection layer 38 positioned in the region of the first contact surface 20.1 of the first component 20 and/or a connection layer 38 positioned in the region of the second contact surface 22.1 of the second component 22.

[0065] According to a first operating method, at least one connection layer 38, 38 38 is positioned just before the step of generating the induced electrical current.

[0066] According to another operating method, at least one connection layer 38, 38 positioned in the region of a contact surface 20.1 or 22.2 is integrated in the component 20, 22 before a step of consolidating the component 20, 22.

[0067] While at least one exemplary embodiment of the invention(s) is disclosed herein, it should be understood that modifications, substitutions and alternatives may be apparent to one of ordinary skill in the art and can be made without departing from the scope of this disclosure. This disclosure is intended to cover any adaptations or variations of the exemplary embodiment(s). In addition, in this disclosure, the terms comprise or comprising do not exclude other elements or steps, the terms a, an or one do not exclude a plural number, and the term or means either or both. Furthermore, characteristics or steps which have been described may also be used in combination with other characteristics or steps and in any order unless the disclosure or context suggests otherwise. This disclosure hereby incorporates by reference the complete disclosure of any patent or application from which it claims benefit or priority.