METHOD OF FORMING AND INDIRECT TESTING OF A BOND ON OR IN AN AIRCRAFT COMPONENT
(19)AUSTRALIAN PATENT OFFICE (54) Title METHOD OF FORMING AND INDIRECT TESTING OF A BOND ON OR IN AN AIRCRAFTCOMPONENT (51)6 International Patent Classification(s) B64F 005/00 GO IN 019/00 B29C 073/04 B32B 035/00 G01N 003/00 B64C 003/00 (21) Application No: 2002350955 (22) Application Date: 2002.12.13 (87) WIPONo: WO03/055747 (30) Priority Data (31) Number (32) Date 0130853.5 2001.12.22 (33) Country GB (43) Publication Date : 2003.07.15 (43) Publication Journal Date : 2003.09.04 (71) Applicant(s) BAE SYSTEMS PLC (72) Inventor(s) MCBROOM, Geoffrey, Peter (H) Application NoAU2002350955 A1(19)AUSTRALIAN PATENT OFFICE (54) Title METHOD OF FORMING AND INDIRECT TESTING OF A BOND ON OR IN AN AIRCRAFTCOMPONENT (51)6 International Patent Classification(s) B64F 005/00 GO IN 019/00 B29C 073/04 B32B 035/00 G01N 003/00 B64C 003/00 (21) Application No: 2002350955 (22) Application Date: 2002.12.13 (87) WIPONo: WO03/055747 (30) Priority Data (31) Number (32) Date 0130853.5 2001.12.22 (33) Country GB (43) Publication Date : 2003.07.15 (43) Publication Journal Date : 2003.09.04 (71) Applicant(s) BAE SYSTEMS PLC (72) Inventor(s) MCBROOM, Geoffrey, Peter A method, in which a damaged site of a composite material structure, for example a wing skin on an aircraft, is repaired, includes the steps of repairing the damaged site with repair material, including adhesive, and at the same time bonding a test fixture, for example a button, at a test site next to the repair, by means of material that is the same as the repair material. The conditions to which the damaged site and the test site are subjected are substantially the same. After repair, the strength of the repair bond may be indirectly assessed by applying a torque to the test fixture, so as to assess the bond strength of the test fixture to the structure. A method of forming a bond comprising the following steps:
providing an aircraft component (1) including a first site (2) at which a bond is required, forming the bond with bonding material (5) at the first site, characterised by bonding a test element (4) at a second site (3) of the aircraft component thereby forming a test bond, the second site being in the vicinity of the first site, the test element being so arranged that, after bonding the test element, the strength of the test bond may be assessed, wherein the test element is bonded to the aircraft component with the use of material (6) that is the same as the bonding material (5), and the conditions to which the second site is subjected during the forming of the test bond are substantially the same as the conditions to which the first site is subjected during the forming of the bond, whereby after the forming of the bond at the first site, the strength of the bond so formed may be assessed, without needing to test the bond directly, by assessing the strength of the test bond. A method according to claim 1, wherein the second site (3) is directly adjacent to the first site. A method according to claim 1 or claim 2, wherein the steps of forming the bond and of bonding a test element incorporate the use of bonding material (6) that is heat cured. A method according to any preceding claim, wherein the step of bonding the test element (4) is performed to produce a test bond having a predetermined contact area by providing a barrier to limit the flow of bonding material during curing of the test bond. A method according to claim 3 or claim 4, when claim 4 is dependent on claim 3, wherein the step of bonding the test element (4) includes positioning a skirt (9) around the bonding material used to bond the test element to the aircraft component (1), then heat curing the bonding material (5), and then removing the skirt. A method according to any preceding claim, wherein the aircraft component is a laminated composite material structure and the steps of forming a bond and of bonding a test element incorporate the use of at least one ply of laminate composite material. A method according to any preceding claim, including performing a further step, after forming the bond, of applying a force to the test element (4) to assess indirectly the strength of the bond at the first site. A method according to any preceding claim, wherein the bond is formed at the first site (2) as part of a step of repairing a damaged portion at the first site of the aircraft component. A method according to any preceding claim, wherein the bond is formed at the first site (2) as part of a step of manufacturing an aircraft component. An aircraft component including a bond at a first site (2) andcharacterised by a test element (4) bonded to the component (1) at a second site with a test bond employing material that is the same as material used in the bond at the first site. An aircraft component according to claim 10 when incorporated into an aircraft. A kit including bonding material (6) for forming a bond and being characterised by a test element (4), the test element having a portion for bonding to an aircraft component (1) and being adapted for having a force applied thereto whereby to apply a shear force to the bond. A kit as in claim 12 in which the test element (4) includes a portion (7, 113) shaped to co-operate with a corresponding portion of a tool for applying a torque to the bond. A kit as in claim 13 in which the portion shaped to co-operate with a tool comprises a recess (113). A kit as in claim 13 or 14 in which the portion (7, 113) shaped to co-operate with a tool is made of metal and the majority of the portion (11, 111) to be bonded to the aircraft component comprises composite material. A kit as in any of claims 12 to 15 in which the test element (4) includes a woven fibre reinforced composite material body (8, 10, 11). A kit as in any of claims 12 to 16 including a skirt for positioning around the bonding material used to bond the test element to the aircraft component.