Composite structure repair process

• US 6,174,392 B1
• Filed: 03/04/1999
• Issued: 01/16/2001
• Est. Priority Date: 03/04/1999
• Status: Expired due to Fees

• Current Assignee: Northrop Grumman Systems Corporation (Northrop Grumman Corporation)
• Original Assignee: Northrop Grumman Corporation
• Inventors: Reis, Carl Andrew
• Primary Examiner(s): Ball, Michael W.
• Assistant Examiner(s): CORCORAN, GLADYS JOSEFINA-PIA
• Application Number:
  US09/262,807
• Time in Patent Office: 684 Days
• Field of Search: 156/58, 156/64, 156/94, 156/98, 356/2, 382/154, 382/285, 382/286, 382/302, 702/166, 702/167, 702/171
• US Class Current: 156/58
• CPC Class Codes: B29C 2073/264 for cutting out or grooving the area to be repaired
• CPC Class Codes: B29C 73/06 using plugs sealing in the hole
• CPC Class Codes: B29C 73/26 for mechanical pretreatment
• CPC Class Codes: B32B 43/00 Operations specially adapted for layered products and not otherwise provided for, e.g. repairing; Apparatus therefor

Abstract

A method for repairing a multi-layered damage area in a multi-layered composite structure. The method first includes obtaining depth measurement data, and obtaining topographical measurement data by laser scanning the surface of the damage area. This depth measurement data and topographical measurement data are inputted into a microprocessor along with thickness data of each layer. All inputted information is correlated among itself to thereby internally produce a three-dimensional damage area display-replica and interpolate a two-dimensional pattern of each layer of the damage area and of the surface of the damage area. The damage area is removed by first projecting a two-dimensional laser pattern of the damage area thereat on the surface of the structure, and thereafter manually removing the area to produce a void. Repair is accomplished by projecting onto respective replacement material a two-dimensional laser image pattern of each layer and manually cutting that layer according to the appropriate pattern. The cut layers then are arranged in accord with construction of the removed damage area to form a plug that is placed within the void.

Claims

1. A method for repairing a multi-layered damage area in a multi-layered composite structure, said damage area having a surface, a width dimension and a depth dimension and disposed on a surface of the composite structure, the method comprising:

a) measuring the depth dimension of the damage area to obtain depth measurement data;

b) scanning the surface of the composite structure with a laser to obtain topographical measurement data of the damage area;

c) inputting into a microprocessor for correlation there among thickness data of each layer of the damage area, said depth measurement data, and said topographical measurement data to thereby produce a three-dimensional display-replica of the damage area and interpolate a two-dimensional pattern of each layer of the damage area and of the surface of the damage area;

d) projecting by laser a two-dimensional pattern of the damage area at the damage area on the surface of the structure;

e) manually removing from the structure the damage area and any non-damaged material above or beneath the damage area and whose width resides within a maximum width of the damage area to thereby produce both a void in accord with the pattern projected thereon and a removed damage area;

f) projecting onto respective replacement material a two-dimensional laser image pattern of each layer of the damage area, manually cutting each layer according to the pattern, arranging layers so cut in accordance with construction of the removed damage area to form a plug, and placing said plug within the void to thereby replace the damage area.

2. A method for repairing a multi-layered damage area in a multi-layered composite structure as claimed in claim 1 wherein location data of non-damage area structures adjacent the damage area is additionally inputted into the microprocessor.

3. A method for repairing a multi-layered damage area in a multi-layered composite structure as claimed in claim 1 wherein said depth dimension is measured ultrasonically.

4. A method for repairing a multi-layered damage area in a multi-layered composite structure as claimed in claim 1 wherein in step (d) thereof the laser is spaced from the composite structure when projecting a two-dimensional pattern of the damage area.

5. A method for repairing a multi-layered damage area in a multi-layered composite structure as claimed in claim 1 wherein the removed damage area and the plug each has a width dimension to depth dimension relationship constant.

6. A method for repairing a multi-layered damage area in a multi-layered composite structure as claimed in claim 5 wherein the width dimension to depth dimension relationship constant of both the removed-damage area and the plug is 20:

1.