Adhesively bonded joints in carbon fibre composite structures

• US 6,320,118 B1
• Filed: 09/17/1999
• Issued: 11/20/2001
• Est. Priority Date: 04/04/1998
• Status: Expired due to Term

• Current Assignee: BAE Systems Plc
• Original Assignee: BAE Systems Plc
• Inventors: Duffy, Roger P, Jones, Christopher C. R., Pridham, Barry J
• Primary Examiner(s): Reichard, Dean A.
• Assistant Examiner(s): WALKENHORST, DAVID W
• Application Number:
  US09/397,867
• Time in Patent Office: 795 Days
• Field of Search: 174/2, 174/84.R, 244/1.A, 244/131, 244/133, 361/216, 361/218
• US Class Current: 174/2
• CPC Class Codes: B29C 65/483 Reactive adhesives, e.g. chemically curing adhesives
• CPC Class Codes: B29C 65/4855 characterised by their physical properties, e.g. being electrically-conductive
• CPC Class Codes: B29C 65/488 being longitudinal, e.g. fibres
• CPC Class Codes: B29C 65/4885 characterised by their composition being non-plastics
• CPC Class Codes: B29C 65/562 using extra joining elements, i.e. which are not integral with the parts to be joined using plastic snap elements B29C65/58; using plastic rivets B29C65/601
• CPC Class Codes: B29C 66/112 Single lapped joints
• CPC Class Codes: B29C 66/131 Single flanged joints, i.e. one of the parts to be joined being rigid and flanged in the joint area
• CPC Class Codes: B29C 66/43441 with two right angles, e.g. for making T-shaped pieces, H-shaped pieces
• CPC Class Codes: B29C 66/474 said single elements being substantially non-flat
• CPC Class Codes: B29C 66/524 Joining profiled elements
• CPC Class Codes: B29C 66/7212 characterised by the composition of the fibres
• CPC Class Codes: B29C 66/72143 Fibres of discontinuous lengths
• CPC Class Codes: B29K 2105/06 containing reinforcements, fillers or inserts
• CPC Class Codes: B29K 2307/00 Use of elements other than metals as reinforcement
• CPC Class Codes: B29K 2307/04 Carbon
• CPC Class Codes: B29L 2031/7172 Fuel tanks, jerry cans
• CPC Class Codes: B64C 1/12 Construction or attachment of skin panels
• CPC Class Codes: B64D 45/02 Lightning protectors; Static dischargers in general H01T

Abstract

A structural joint for the transmission and control of high current flows in a carbon fiber or carbon fiber hybrid composite structure, said joint including

at least two composite structures comprising a multiplicity of resin bonded carbon fiber plies,

an adhesive applied there between and capable of conducting high currents

said adhesive comprising a conductive carrier film comprising carbon fibers,

wherein the electrical conductivity of the adhesive is comparable with that of the adjacent composite structures.

Claims

1. A structural joint for the transmission and control of high current flows in a joint between at least two carbon fibre or carbon fibre hybrid composite structures, said joint comprising:

said at least two composite structures comprising a multiplicity of resin bonded carbon fibre plies,

an adhesive applied to said joint between said composite structures and capable of conducting high currents through and away from the joint,

said adhesive comprising a conductive carrier film comprising carbon fibres,

wherein the electrical conductivity of the adhesive is comparable with that of the adjacent composite structures,

and wherein the adhesive, once cured, acts to adhesively bond the two composite structures together to form a load-bearing structural joint.

2. A structural joint according to claim 1 wherein the carbon fibres in the adhesive are in the form of a lightweight scrim.

3. A structural joint according to claim 1 wherein the carbon fibres in the adhesive are in the form of chopped fibres.

4. A structural joint according to claim 1 wherein an electrically conductive layer is incorporated in or is applied to an outer surface of at least one of said composite structures.

5. A structural joint according to claim 4 wherein the electrically conductive layer is a copper strip.

6. A structural joint according to claim 4 wherein conductive fasteners are in contact with the electrically conductive layer.

7. A structural joint for the transmission and control of high current flows in a carbon fibre or carbon fibre hybrid composite structure, said joint comprising:

at least two composite structures comprising a multiplicity of resin bonded carbon fibre plies,

an adhesive applied there between and capable of conducting high currents through and away from the joint,

said adhesive comprising a conductive carrier film comprising carbon fibres,

wherein the electrical conductivity of the adhesive is comparable with that of the adjacent composite structures, wherein an electrically conductive layer is incorporated in or is applied to an outer surface of at least one of said composite structures.

8. A structural joint according to claim 7 wherein the electrically conductive layer is a copper strip.

9. A structural joint according to claim 7 wherein conductive fasteners are in contact with the electrically conductive layer.

10. An adhesive for bonding carbon fibre or carbon fibre hybrid composite structures wherein the adhesive conducts high current, comprises a conductive carrier film comprising carbon fibres, has an electrical conductivity comparable with that of the adjacent carbon fibre or carbon fibre hybrid composite structures, and, when cured, creates a high strength bond between the composite structures which is of sufficient strength to act as a load-bearing structural joint.

11. An adhesive according to claim 10 wherein the carbon fibres therein are in the form of a lightweight scrim.

12. An adhesive according to claim 10 wherein the carbon fibres therein are in the form of chopped fibres.

13. An adhesive according to claim 10 wherein the electrical conductivity of the adhesive is comparable with that of the adjacent carbon fibre or carbon fibre hybrid composite structures.

14. A method of forming a structural joint including the steps of

providing two or more carbon fibre or carbon fibre hybrid composite structures,

applying an adhesive between said structures forming a joint, and

curing the joint to form a load-bearing structural joint, wherein the adhesive conducts high currents through and away from the joint, the adhesive comprising a conductive carrier film comprising carbon fibres and has an electrical conductivity comparable with that of the adjacent composite structures.