Multi-layer metallic structure and composite-to-metal joint methods

• US 8,993,084 B2
• Filed: 04/10/2012
• Issued: 03/31/2015
• Est. Priority Date: 08/17/2010
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Griess, Kenneth Harlan, Georgeson, Gary E.
• Primary Examiner(s): THOMAS, ALEXANDER S
• Application Number:
  US13/443,687
• Publication Number:
  US 20130075526A1
• Time in Patent Office: 1,085 Days
• Field of Search: 428/60, 428/58, 428/61
• US Class Current: 428/60
• CPC Class Codes: B29C 65/02 by heating, with or without pressure
• CPC Class Codes: B29C 65/48 using adhesives , i.e. using supplementary joining material; solvent bonding
• 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 65/72 by combined operations or combined techniques, e.g. welding and stitching
• CPC Class Codes: B29C 66/1248 Interpenetrating groove joints interpenetrating fingered joints B29C66/139
• CPC Class Codes: B29C 66/1282 comprising at least one overlap joint-segment
• CPC Class Codes: B29C 66/12861 comprising at least two bevelled joint-segments
• CPC Class Codes: B29C 66/14 the joint having the same thickness as the thickness of the parts to be joined B29C66/1142 takes precedence
• CPC Class Codes: B29C 66/24221 being circular B29C66/51 takes precedence
• CPC Class Codes: B29C 66/43 Joining a relatively small portion of the surface of said articles B29C66/45 takes precedence
• CPC Class Codes: B29C 66/50 General aspects of joining tubular articles; General aspects of joining long products, i.e. bars or profiled elements; General aspects of joining single elements to tubular articles, hollow articles or bars; General aspects of joining several hollow-preforms to form hollow or tubular articles
• CPC Class Codes: B29C 66/71 characterised by the composition of the plastics material of the parts to be joined welding bar compositions B29C65/125
• CPC Class Codes: B29C 66/712 the composition of one of the parts to be joined being different from the composition of the other part
• CPC Class Codes: B29C 66/721 Fibre-reinforced materials B29C66/729 takes precedence
• CPC Class Codes: B29C 66/7212 characterised by the composition of the fibres
• CPC Class Codes: B29C 66/723 being multi-layered B29C66/7292, B29C66/72941 take precedence
• CPC Class Codes: B29C 66/72321 consisting of metals or their alloys
• CPC Class Codes: B29C 66/742 to metals or their alloys
• CPC Class Codes: B29C 70/304 In-plane lamination by juxtaposing or interleaving of plies, e.g. scarf joining
• CPC Class Codes: B29C 70/86 Incorporated in coherent impregnated reinforcing layers, e.g. by winding
• CPC Class Codes: B29C 70/885 : with incorporated metallic wires, nets, films or plates as lost heating elements B29C35/0272, B29C61/0625
• CPC Class Codes: B29K 2063/00 : Use of EP, i.e. epoxy resins or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2307/04 : Carbon
• CPC Class Codes: B29K 2309/08 : Glass
• CPC Class Codes: B29L 2031/3002 : Superstructures characterized by combining metal and plastics, i.e. hybrid parts
• CPC Class Codes: B29L 2031/3079 : Cockpits, canopies
• CPC Class Codes: B29L 2031/3082 : Fuselages
• CPC Class Codes: B29L 2031/3085 : Wings
• CPC Class Codes: B29L 2031/3088 : Helicopters
• CPC Class Codes: B32B 15/01 : all layers being exclusively metallic making layered metal workpieces by pressure cladding B23K20/22; making coatings with a metallic material characterised by its composition C23C30/00
• CPC Class Codes: B32B 15/08 : of synthetic resin
• CPC Class Codes: B32B 15/14 : next to a fibrous or filamentary layer
• CPC Class Codes: B32B 2250/05 : 5 or more layers
• CPC Class Codes: B32B 2250/20 : All layers being fibrous or filamentary
• CPC Class Codes: B32B 2260/023 : Two or more layers
• CPC Class Codes: B32B 2260/046 : Synthetic resin
• CPC Class Codes: B32B 2262/106 : Carbon fibres, e.g. graphite fibres
• CPC Class Codes: B32B 2305/076 : Prepregs
• CPC Class Codes: B32B 2305/77 : Uncured, e.g. green
• CPC Class Codes: B32B 2307/714 : Inert, i.e. inert to chemical degradation, corrosion
• CPC Class Codes: B32B 2605/18 : Aircraft
• CPC Class Codes: B32B 3/06 : for securing layers together; for attaching the product to another member, e.g. to a support , or to another product, e.g. groove/tongue, interlocking
• CPC Class Codes: B32B 3/14 : characterised by a face layer formed of separate pieces of material which are juxtaposed side-by-side B32B5/02 takes precedence
• CPC Class Codes: B32B 3/18 : characterised by an internal layer formed of separate pieces of material which are juxtaposed side-by-side B32B5/02 takes precedence
• CPC Class Codes: B32B 37/12 : characterised by using adhesives
• CPC Class Codes: B32B 37/144 : using layers with different mechanical or chemical conditions or properties, e.g. layers with different thermal shrinkage, layers under tension during bonding constructional features for tensioning B32B38/1825
• CPC Class Codes: B32B 37/182 : one or more of the layers being plastic
• CPC Class Codes: B32B 5/26 : another layer next to it also being fibrous or filamentary relative arrangement of fibres or filaments of different layers B32B5/12
• CPC Class Codes: B32B 5/28 : impregnated with or embedded in a plastic substance not used
• CPC Class Codes: B32B 7/12 : using interposed adhesives or interposed materials with bonding properties
• CPC Class Codes: B64C 1/061 : Frames
• CPC Class Codes: B64C 1/12 : Construction or attachment of skin panels
• CPC Class Codes: C22C 14/00 : Alloys based on titanium
• CPC Class Codes: Y02T 50/40 : Weight reduction
• CPC Class Codes: Y10T 156/10 : Methods of surface bonding and/or assembly therefor
• CPC Class Codes: Y10T 403/70 : Interfitted members
• CPC Class Codes: Y10T 428/12007 : Component of composite having metal continuous phase interengaged with nonmetal continuous phase
• CPC Class Codes: Y10T 428/12347 : Plural layers discontinuously bonded [e.g., spot-weld, mechanical fastener, etc.]
• CPC Class Codes: Y10T 428/12361 : having aperture or cut
• CPC Class Codes: Y10T 428/12493 : Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
• CPC Class Codes: Y10T 428/19 : Sheets or webs edge spliced or joined
• CPC Class Codes: Y10T 428/195 : Beveled, stepped, or skived in thickness
• CPC Class Codes: Y10T 428/31678 : Of metal

Abstract

A composite structure comprises stacked sets of laminated fiber reinforced resin plies and metal sheets. Edges of the resin plies and metal sheets are interleaved to form a composite-to-metal joint connecting the resin plies with the metal sheets.

Claims

1. An integrated attachment fitting for a structure, comprising:

a composite resin portion comprising layers of composite laminate;

a metal portion comprising a stack of metal plies, each metal ply in the stack of metal plies being substantially chemically non-reactive with any abutting composite resin, and connected to an adjoining metal ply via an adhesive layer such that;

the stack of metal plies comprises performance properties superior to those of any monolithic metal comprising a thickness equal to a thickness of the stack of metal plies, and a reduction in a load carrying capability of any one ply in the stack of metal plies results in a transfer of the load across all other plies in the stack of plies, an end of each metal ply being vertically aligned with an end of a non-adjacent metal ply; and

a composite-to-metal joint between the composite resin portion and the metal portion such that each composite laminate comprises a thickness that is less than a thickness of any metal ply whose end abuts a termination of the each composite laminate, such that terminations of some composite laminates in the composite resin portion are recessed from a vertical alignment of terminations of composite laminates in the composite resin portion that are not recessed, and the termination of each of the some composite laminates is vertically aligned with a termination of each other of the some composite laminates and the termination of each of the some composite laminates abuts the end of an individual metal ply in the stack of metal plies to form a vertical lap finger joint, and each metal ply abuts multiple layers of composite laminate.

2. The integrated attachment fitting of claim 1, wherein:

the composite resin portion includes a plurality of fiber reinforced resin plies, and each metal ply abuts at least three fiber reinforced plies.

3. The integrated attachment fitting of claim 2, wherein the composite-to-metal joint comprises overlapping steps between the fiber reinforced resin plies and the stack of metal plies, a length of an overlap of the overlapping steps determined by a load requirement of the integrated attachment fitting.

4. The integrated attachment fitting of claim 3, wherein the composite-to-metal joint is a finger joint and a first metal ply in the stack of metal plies comprises a different metal from a second metal ply in the stack of metal plies.

5. The integrated attachment fitting of claim 1, wherein the structure is an aircraft wing and the metal portion is a metal laminate having a plurality of through holes therein adapted to receive fasteners for attaching the wing to a center wing box on an aircraft fuselage.

6. The integrated attachment fitting of claim 1, wherein the structure is an aircraft wing and the metal portion is a metal laminate having a plurality of through holes therein adapted to receive fasteners, and further comprising a second composite portion such that forms a second composite-to-metal joint with the metal portion.

7. A fastener reinforcement for reinforcing an area of a multi-ply composite structure, comprising:

a metal laminate including a plurality of metal sheets bonded together, the metal laminate having a through hole therein adapted to receive a fastener therein, each metal sheet within the metal sheets bonded together comprising a shape being substantially circular and each metal sheet within the metal sheets bonded together comprising a radius that differs from a radius of an adjacent metal sheet within the metal sheets bonded together; and

a composite-to-metal joint between the metal laminate and the composite structure, the composite-to-metal joint comprising a variation in the radius relative to the radius of the adjacent metal sheet in the metal sheets bonded together being determined by a specified thermal expansion interface coefficient, such that multiple layers of composite laminate circumferentially abut a perimeter edge of each metal sheet respectively.

8. The fastener reinforcement of claim 7, wherein the metal sheets comprise edges that are interleafed with edges of the plies of the composite structure, and further comprising the variation in the radius of one metal sheet relative to the radius of adjacent metal sheets in the metal sheets bonded together determined by a load requirement for the fastener.

9. An apparatus that increases a capacity of a joint, between a first composite structure and a second composite structure, to carry a load, over the capacity of the joint to carry the load without the apparatus, the apparatus comprising:

a first metal laminate comprising first metal sheets bonded to each other by an adhesive layer between each metal sheet that adjoins another metal sheet, each metal sheet in the first metal sheets comprising;

a first edge that aligns vertically with a first edge of each other metal sheet in the first metal sheets, such that the first metal laminate comprises performance properties superior to a monolithic metal structure of a width equal to a width of the first metal laminate, such that a load on a particular sheet in the first metal laminate redistributes to remaining metal sheets in the first metal laminate when a load carrying capacity of the particular sheet in the first metal laminate reduces; and

a second edge that abuts and bonds to multiple layers of fiber reinforced composite resin within the first composite structure, such that the second edge of each sheet aligns with the second edge of other first metal sheets in the first metal laminate in a vertical lap finger joint with the first composite structure, an overlap length in the vertical lap finger joint with the first composite structure being determined by a specified thermal expansion interface coefficient, and the second edge of each metal sheet in the first metal sheets being substantially non-reactive with the fiber reinforced composite resin that abuts each metal sheet respectively;

a second metal laminate comprising second metal sheets, each sheet in the second metal sheets comprising;

a first edge that aligns vertically with a first edge of each other sheet in the second metal sheets, such that the second metal laminate comprises performance properties superior to a monolithic metal structure of a width equal to a width of the second metal laminate, such that a load on a particular sheet in the second metal laminate redistributes to remaining metal sheets in the second metal laminate when a load carrying capacity of the particular sheet in the second metal laminate reduces; and

a second edge that abuts and bonds to multiple layers of fiber reinforced composite resin within the second composite structure, such that the second edge of each sheet aligns with the second edge of other second metal sheets in the second metal laminate in a lap finger joint with the second composite structure, overlap lengths in the lap finger joint with the second composite structure being determined by a specified thermal expansion interface coefficient, and the second edge of each metal sheet in the second metal sheets being substantially non-reactive with the fiber reinforced composite resin that abuts each metal sheet respectively; and

a joint that bonds the first metal laminate to the second metal laminate, the joint comprising;

an overlap of the first metal laminate and the second metal laminate, a length of the overlap comprising an adhesive layer that bonds a metal sheet of the first metal laminate to a metal sheet of the second metal laminate; and

a through hole in the first metal laminate aligned with a through hole in the second metal laminate, each through hole filled by a single fastener, the joint comprising characteristics of;

a strength, a resistance to disbonds, and a resistance to propagation of inconsistencies, greater than those characteristics found in a monolithic metal comprising a thickness equal to a thickness of the joint that bonds the first metal laminate to the second metal laminate.

10. The apparatus of claim 9, such that a first metal sheet in the first metal laminate comprises a metal that differs from a metal in a second metal sheet in the first metal laminate, and a first metal sheet in the second metal laminate comprises a metal that differs from a second metal sheet in the second metal laminate.