# US 8,540,916 B2 · Curved structural part made of composite material and a process for manufacturing such a part

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- Number: US 8,540,916 B2
- Document ID: US8540916B2
- Status: Granted
- Kind: B2
- Application number: 13/309,625
- Filed: 2011-12-02
- Published: 2012-04-26
- Granted: 2013-09-24
- Earliest claimed: 2008-11-21
- Assignees: Airbus Operations GmbH
- Applicants: Vanessa Kubryk; Nathalie Hellard-Lambic
- Inventors: Vanessa Kubryk; Nathalie Hellard-Lambic
- Web page: https://patentgrep.com/patent/US8540916B2

## CPC

- B29C 70/342: {using isostatic pressure}
- B29C 70/202: {arranged in parallel planes or structures of fibres crossing at substantial angles, e.g. cross-moulding compound [XMC] (B29C70/207 takes precedence)}
- B29C 70/302: {Details of the edges of fibre composites, e.g. edge finishing or means to avoid delamination}
- B29D 99/0007: {having a variable cross-section}
- B64C 1/061: {Frames}
- B29C 70/42: for producing articles of definite length, i.e. discrete articles
- B29L 2031/003: {having a profiled transverse cross-section}
- B29L 2031/3082: {Fuselages}
- B64C 2001/0072: {from composite materials}
- Y02T 50/40: Weight reduction
- Y10T 156/1002: with permanent bending or reshaping or surface deformation of self sustaining lamina
- Y10T 156/1052: with cutting, punching, tearing or severing
- Y10T 156/1084: of continuous or running length bonded web
- Y10T 156/12: Surface bonding means and/or assembly means with cutting, punching, piercing, severing or tearing
- Y10T 428/24058: including grain, strips, or filamentary elements in respective layers or components in angular relation
- Y10T 428/24091: with additional layer[s]
- Y10T 428/24116: Oblique to direction of web
- Y10T 428/2419: Fold at edge
- Y10T 428/24479: including variation in thickness
- Y10T 428/24628: Nonplanar uniform thickness material
- Y10T 428/24645: with folds in parallel planes
- B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00)
- B29D: PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE (making granules B29B9/00; making preforms B29B11/00)
- B64C: AEROPLANES; HELICOPTERS
- B29L: INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

A process for manufacturing a curved structural part includes fabricating a mold of the curved structural part having at least two faces that form a male mold section between a minimum radius of curvature of the curved structural part and another radius of curvature belonging to one of the two faces, preparing a stack of multidirectional fibers of one or more fiber plies oriented ±α or 90° in relation to a longitudinal direction of the curved structural part, cutting a first multidirectional strip in the stack extending longitudinally and having a width at least equal to a maximum width of the curved structural part, applying the first multidirectional strip over the mold to gradually conform the first multidirectional strip to the mold, applying the first multidirectional strip on the face having the minimum radius of curvature, and pressing and tightening the first multidirectional strip over the other faces.

## Claims

### Claim 1

A process for manufacturing a curved structural part comprising a composite material reinforced with continuous fibers, wherein a cross section of the curved structural part includes at least two wings, with said fibers extending from one wing to the other, the curved structural part being curved with a radius of curvature and having a width parallel to the radius of curvature, with a section having a local increase in the width parallel to a local radius of curvature, the width increasing in a direction towards an interior of a curve of the curved structural part, the process comprising:
fabricating a mold of the curved structural part having at least two faces, with said two faces forming a male mold section between a minimum radius of curvature of the curved structural part corresponding to the local increase in the width of the section of the curved structural part and another radius of curvature belonging to one of the two faces;
preparing a stack of multidirectional fibers comprising one or more fiber plies oriented in a nominal direction of +/−α or 90° in relation to a longitudinal direction of the curved structural part where α is in the range of 30° to 60°;
cutting a first multidirectional strip in the stack extending longitudinally and having a width at least equal to a maximum width of the curved structural part;
applying the first multidirectional strip over the mold by pressing to gradually conform the first multidirectional strip to the mold;
initiating the application of the first multidirectional strip on the face having the minimum radius of curvature in an area corresponding to the local increase in the width of the section of the curved structural part; and
pressing and tightening the first multidirectional strip over the other faces.

### Claim 2 (depends on 1)

The process of claim 1, further comprising placing a second strip of fibers oriented at 0° along the local radius of curvature over at least one wing prior to placing the first multidirectional strip or between placing the first and a second multidirectional strip.

### Claim 3 (depends on 1)

The process of claim 1, further comprising placing a second multidirectional strip having at least two plies oriented at +α and −α in relation to the longitudinal direction of said first multidirectional strip.

### Claim 4 (depends on 3)

The process of claim 3, wherein α is equal to 30°.

### Claim 5 (depends on 3)

The process of claim 3, wherein α is equal to 45°.

### Claim 6 (depends on 1)

The process of claim 1, further comprising placing a second multidirectional strip having at least two plies oriented at 90° and at +α in relation to the longitudinal direction of said first multidirectional strip, followed by the placement of a third multidirectional strip having at least two plies oriented at 90° and −α in relation to the longitudinal direction of said first multidirectional strip.

### Claim 7 (depends on 1)

The process of claim 1, further comprising draping and spreading additional plies to increase a thickness of the curved structural part in the area corresponding to the local increase in the width of the section of the curved structural part.

### Claim 8 (depends on 7)

The process of claim 7, wherein the increase of the thickness of the curved structural part is provided by a gradient of approximately 0.2.