Metallic-composite joint

Abstract

The invention provides a method of manufacturing a metallic-composite joint comprising a metallic component having one hole in a surface thereof, and a metallic fastener having a head portion for attaching to the metallic component and a tail portion for attaching to a composite component, comprising the steps of positioning the metallic fastener such that the head portion of the metallic fastener is retained in the hole, and the tail portion of the metallic fastener extends out of the hole, arranging layered fibers of an uncured composite component on the surface of the metallic component such that the tail portion extends through a gap between adjacent fibers in each fiber layer, and curing the composite component. The invention also provides a metallic-composite joint, a structure, an aircraft structure, an aircraft, a method of manufacturing a fastener assembly, a fastener assembly and a metallic fastener.

Claims

1. A method of manufacturing a metallic-composite joint, the metallic-composite joint comprising: a metallic component, the metallic component having at least one hole in a surface thereof, and a metallic fastener, the metallic fastener having a head portion for attaching to the metallic component and a tail portion for attaching to a composite component, the method of manufacturing a metallic-composite joint comprising the steps of: positioning the metallic fastener such that: at least a part of the head portion of the metallic fastener is retained in the hole of the metallic component, and the tail portion of the metallic fastener extends out of the hole and away from the surface of the metallic component, arranging layered fibres of an uncured composite component on the surface of the metallic component, after positioning the metallic fastener through the hole in the metallic component, such that the tail portion extends through a gap between adjacent fibres in each fibre layer of the arranged layered fibres prior to curing of the composite component, and curing the composite component, thereby attaching the composite component to the tail portion of the metallic fastener.

2. A method of manufacturing a metallic-composite joint as claimed in claim 1, wherein the arranging of the layered fibres comprises the steps of: laying up the fibres in layers, then positioning the layers adjacent an end of the tail portion distal from the surface of the metallic component, and then shaking the layers so that the tail portion to passes through the gap in each layer.

3. A method of manufacturing a metallic-composite joint as claimed in claim 1, wherein the arranging of the layered fibres comprises the step of: for each layer, laying up the fibres on the metallic component such that two adjacent fibres pass on substantially opposite sides of the tail portion of the metallic fastener so that the tail portion extends through the layer.

4. A method of manufacturing a metallic-composite joint as claimed in claim 1, wherein either the method further comprises the step of shaping the tail portion or the tail portion of the metallic fastener has already been shaped.

5. A method of manufacturing a metallic-composite joint as claimed in claim 4, wherein the tail portion is or has been shaped to have: an outer region, towards the end of the tail portion furthest away from the head portion, and an inner region, towards the end of the tail portion nearest the head portion, wherein the cross-section at the outer region is larger than at the inner region.

6. A method of manufacturing a metallic-composite joint as claimed in claim 5, wherein the tail portion is or has been shaped to have an intermediate region, in between the inner and outer regions, with a cross-section smaller than the inner region.

7. A method of manufacturing a metallic-composite joint as claimed in claim 4, wherein the tail portion is or has been shaped so that the end of the tail portion furthest away from the head portion is tapered.

8. A method of manufacturing a metallic-composite joint as claimed in claim 1, wherein either the method further comprises the step of shaping the head portion or the head portion of the metallic fastener has already been shaped.

9. A method of manufacturing a metallic-composite joint as claimed in claim 8, wherein the head portion is or has been shaped to have: an outer region, towards the end of the head portion furthest away from the tail portion, an inner region, towards the end of the head portion nearest the tail portion, wherein the cross-section at the outer region is larger than at the inner region.

10. A method of manufacturing a metallic-composite joint as claimed in claim 9, wherein the outer region of the head portion is or has been chamfered to correspond to a chamfered region of the hole in the metallic component.

11. A method of manufacturing a metallic-composite joint as claimed in claim 1, wherein, after the metallic fastener is positioned in the hole of the metallic component, the metallic fastener is shaped to have a securing lip at a junction of the head portion and tail portion, for securing the head portion in the hole.

12. A method of manufacturing a metallic-composite joint as claimed in claim 11, wherein the metallic component has a correspondingly shaped recess to accommodate the securing lip.

13. A method of manufacturing a metallic-composite joint as claimed in claim 1, wherein the head portion of the metallic fastener is retained in the hole of the metallic component at least partially by an interference fit.

14. A method of manufacturing a metallic-composite joint as claimed in claim 1, wherein the hole in the metallic component is a through-hole extending through a thickness of the metallic component.

15. A method of manufacturing a metallic-composite joint as claimed in claim 1, wherein the method further includes the step of cutting a wire feed stock to form the metallic fastener.

16. A method of manufacturing a fastener assembly, the fastener assembly comprising: a metallic component, the metallic component having at least one hole in a surface thereof, and a metallic fastener, the metallic fastener having a head portion for attaching to the metallic component and a tail portion for attaching to a composite component, the method comprising the steps of: positioning the metallic fastener such that: at least a part of the head portion of the metallic fastener is retained in the hole of the metallic component, and the tail portion of the metallic fastener extends out of the hole and away from the surface of the metallic component, the method comprises arranging layered fibres of an uncured composite material on the surface of the metallic component, after positioning the metallic fastener through the hole in the metallic component, such that the tail portion extends through a gap between adjacent fibres in each fibre layer of the arranged layered fibres prior to curing of the composite material; curing the composite material, thereby attaching the composite component to the tail portion of the metallic fastener, and wherein either the method further comprises the step of shaping the tail portion or the tail portion of the metallic fastener has already been shaped.

17. A method of manufacturing a fastener assembly as claimed in claim 16, wherein the tail portion is or has been shaped to have: an outer region, towards the end of the tail portion furthest away from the head portion, and an inner region, towards the end of the tail portion nearest the head portion, wherein the cross-section at the outer region is larger than at the inner region.

18. A method of manufacturing a fastener assembly as claimed in claim 17, wherein the tail portion is or has been shaped to have an intermediate region, in between the inner and outer regions, with a cross-section smaller than the inner region.

19. A method of manufacturing a fastener assembly as claimed in claim 16, wherein the tail portion is or has been shaped so that the end of the tail portion furthest away from the head portion is tapered.

Description

DESCRIPTION OF THE DRAWINGS

(1) Embodiments of the present invention will now be described by way of example only with reference to the accompanying schematic drawings of which:

(2) FIG. 1a shows a perspective view of a metallic plate for forming a metallic-composite joint according to a first embodiment of the invention;

(3) FIG. 1b shows a metallic wire used to form a fastener for the joint;

(4) FIG. 1c shows the fastener with a shaped head;

(5) FIG. 1d shows a cut-away view of the fastener placed in a hole of the metallic plate;

(6) FIG. 1e shows a cut-away view of the fastener in the plate with a shaped tail;

(7) FIG. 2a shows a second fastener with a shaped head and a shaped tail;

(8) FIG. 2b shows a cut-away view of the fastener placed in a hole of the metallic plate;

(9) FIG. 3a shows a cut-away view of a hole in the plate provided with a chamfer on the top surface;

(10) FIG. 3b shows a cut-away view of a fastener with a shaped head in the hole;

(11) FIG. 3c shows a cut-away view of the fastener with a shaped tail with a lip;

(12) FIG. 4a shows a cut-away view of a hole in the plate provided with a chamfer on the bottom surface;

(13) FIG. 4b shows a fastener with a chamfered head;

(14) FIG. 4c shows a cut-away view of the fastener with a chamfered head in the hole;

(15) FIG. 4d shows a cut-away view of the fastener with a shaped tail;

(16) FIG. 5a shows a fastener with a shaped and chamfered head;

(17) FIG. 5b shows a cut-away view of the fastener in a chamfered hole of the plate;

(18) FIG. 5c shows a cut-away view of the fastener with a shaped tail;

(19) FIG. 6a shows a cut-away view of a non-through hole in a metallic component for forming a metallic-composite joint according to another embodiment of the invention;

(20) FIG. 6b shows a cut-away view of a fastener interference fitted in the hole;

(21) FIG. 6c shows a cut-away view of the fastener with a shaped tail;

(22) FIG. 7 shows the equipment used to form the various joints;

(23) FIG. 8a shows a wire being stopped by the equipment;

(24) FIG. 8b shows the wire being gripped by the equipment;

(25) FIG. 8c shows the wire being punched by the equipment;

(26) FIG. 8d shows the finished fastener in a plate; and

(27) FIG. 9 shows an aircraft including at least one metallic-composite joint.

DETAILED DESCRIPTION

(28) FIGS. 1a to 1e show various steps in the process of manufacturing a metallic-composite joint, according to a first embodiment of the invention. The joint comprises a metallic (aluminium alloy) component (a plate 10) and a composite component (not shown), joined together by a metallic (titanium alloy) fastener 20.

(29) Firstly, as shown in FIG. 1a, the plate 10 is drilled with a number of through-holes 11.

(30) Secondly, as shown in FIG. 1b, a titanium alloy wire 21 used to form the fastener 20 is provided.

(31) Thirdly, as shown in FIG. 1c, the fastener is provided with a shaped head 30, comprising a disc shape 31, at one end of the wire 21.

(32) Fourthly, as shown in FIG. 1d, the fastener 20 is placed in a hole 11 of the plate 10.

(33) Fifthly, as shown in FIG. 1e, the fastener 20 is provided with a shaped tail. 40 at the opposite end of the wire 21 to the head 30. Hence, the fastener comprises a shaft 50, a shaped head 30 and a shaped tail 40. The shaped tail 40 comprises a narrow neck portion 41 in between two sloping sections 42, 43. It also has a pointed end 44.

(34) Sixthly (not shown), a composite component is placed around the fastener above the plate 10. This can be done either by laying up fibre layers so that adjacent fibres lie either side of the fastener or by shaking the fibre layers onto the fastener (aided by the pointed end 44).

(35) Seventhly (not shown), the fibre layers are then cured so that the cured composite component is attached to the fastener. The neck portion 41 and sloping sections 42, 43 also aid in retaining the composite component on the fastener.

(36) Referring to the parts of the fastener 20 that attach to the different parts of the joint, it can be seen that a head portion 22 (defined by the shaped head 30 and a head end of the shaft 50) attaches to the metallic component (plate 10) and a tail portion. 23 (defined by the shaped tail 40 and a tail end of the shaft 50) attaches to the composite component.

(37) In the following Figures sets (2 to 6) various different methods of forming the joints will be described. Only the differences from the method steps described in relation to FIGS. 1a to 1e) will be described.

(38) In Figure set 2, the tail is shaped prior to the fastener being placed in the hole (i.e. FIGS. 2a and 2b replace FIGS. 1d and 1e, respectivelysteps 4 and 5),

(39) In Figure set 3, the hole 11 is provided with a chamfer 12 on the top surface of the plate 10 (see FIG. 3a). When the tail 40 is shaped (with the fastener in the hole 11), the tail includes a lip 45 corresponding to the chamfer 12. This lip 45 retains the plate 10 on the fastener 20. (FIGS. 3a to 3c effectively replace FIGS. 1a, 1d and 1e, respectivelysteps 1, 4 and 5.)

(40) In Figure set 4, the hole 11 is provided with a chamfer 13 on the bottom surface of the plate 10 (see FIG. 4a). The head 30 is shaped (see FIG. 4b) so as to have a matching chamfered portion 32 (instead of the disc 31). The chamfered portion 32 of the head 30 sits in the chamfer 13 on the hole 11 and allows the head to be counter sunk to give a flush bottom surface of the plate 10. (FIGS. 4a to 4d effectively replace FIGS. 1a, 1c, 1d and 1e, respectivelysteps 1, 3, 4 and 5.)

(41) In Figure set 5, the head 30 is shaped so as to have a similar (to FIG. 4b) matching chamfered portion 32 on top of the disc 31. The chamfered portion 32 of the head 30 sits in the chamfer 13 on the hole 11 and allows the chamfered portion 32 of the head to be counter sunk. The disc 31 may be removed afterwards to give a flush bottom surface of the plate 10. (FIGS. 4a and 5a to 5c effectively replace FIGS. 1a, 1c, 1d and 1e, respectively steps 1, 3, 4 and 5.)

(42) In Figure set 6, the metallic (aluminium alloy) component 110 is not a plate. In addition, the hole 111 is not a through-hole. Here, the fastener 20 made out of wire 21 is a larger diameter than the hole 11 and is put into the hole with an interference fit. There is no shaped head 30. After the head portion 22 is attached in the hole 111, the shaped tail 40 is formed, as before. (FIGS. 6a to 6c effectively replace FIGS. 1a to 1e, respectivelysteps 1, 4 and 5 (no step 3).)

(43) FIG. 7 shows the equipment used to form the various joints of the Figure sets. The equipment 200 includes a drill 201 (for drilling and chamfering holes 11, 111 in the plate 10 or component 110) and a wire feed 202 for supplying the wire 21 to make the fasteners 20. The fasteners are formed in the forming apparatus 203.

(44) FIGS. 8a to 8d show the processes which might happen in the forming apparatus 203. Firstly, the wire 21 of the wire feed 202 is fed through a hole in a plate 10 and stopped by a stopper (rivet head) 204 (FIG. 8a). After it is stopped, the wire 21 is squeezed by a two part gripping die 205a, 205b (FIG. 8b) to form the shaped tail 40 of the fastener 20. The dies 205a, 205b also cuts the wire 21 above the tail.

(45) The gripping die 205a, 205b is then pushed down to the plate 10 and the stopper 204 is pushed up to the plate 10 to form the head 30 of the fastener 20 (FIG. 8c). Finally, the stopper 204 and gripping die 205a, 205b are removed (along with the cut wire 21) to another hole in the plate, leaving the fastener 20 in the hole in the plate 10 (FIG. 8d),

(46) FIG. 9 shows an aircraft 300 including at least one metallic-composite joint 301, which has been manufactured by one of the methods described above.

(47) Whilst the present invention has been described and illustrated with reference to particular embodiments, it will be appreciated by those of ordinary skill in the art that the invention lends itself to many different variations not specifically illustrated herein. By way, of example only, certain possible variations will now be described.

(48) The metallic component 10, 110 could be any shape or configuration. For example, it could be a plate, butt strap, stiffener, cleat, bracket, flange or tubular end fitting, for example. The metallic component may be generally planar, curved or non-planar, for example.

(49) The joint may or may not be part of an aircraft. For example, the joint may be for use in sports equipment, such as a bike, a boat hull or a wind turbine blade.

(50) The shaped head 30 and/or shaped tail 40 may take any suitable shape, including the lip 45 of the tail 40 and the chamfered portion 32 of the head 30.

(51) The shaped head 30 and/or shaped tail 40 may be shaped using compressive forming techniques, reciprocal or rotating cylindrical methods.

(52) The head 30 may not be shaped. This could be the case where an interference fit (in a through hole or a non-through hole) is used.

(53) The tail may not be shaped. This could he the case where the arranging of the layered fibres comprises the step of for each layer, laying up the fibres on the metallic component such that two adjacent fibres pass on substantially opposite sides of the tail portion of the metallic fastener so that the tail portion extends through the layer.

(54) The composite component is not necessarily placed directly on the metallic component 10, 110 surface. For example, it is noted that, in order to prevent the, for example, carbon fibres of the composite component being adjacent the aluminium alloy or other material) metallic component, a glass layer can be used in between the composite component and the metallic component. The glass layer may be integral with the (cured) composite component.

(55) The hole 11, 111 in the metallic component 10, 110 may be provided before, during or after the cutting of the wire 21 or the shaping of the head 30 and/or tail 40 of the fastener 20, as appropriate.

(56) Other materials may be used for the metallic component 10, 110 and/or fastener 20.

(57) Where in the foregoing description, integers or elements are mentioned which have known, obvious or foreseeable equivalents, then such equivalents are herein incorporated as if individually set forth. Reference should be made to the claims for determining the true scope of the present invention, which should be construed so as to encompass any such equivalents. It will also be appreciated by the reader that integers or features of the invention that are described as preferable, advantageous, convenient or the like are optional and do not limit the scope of the independent claims. Moreover, it is to be understood that such optional integers or features, whilst of possible benefit in some embodiments of the invention, may not be desirable, and may therefore be absent, in other embodiments.