LAMINATE COMPOSITE WING STRUCTURES

• US 20160207607A1
• Filed: 01/15/2015
• Published: 07/21/2016
• Est. Priority Date: 01/15/2015
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Charles, Jordan, Sampedro-Thompson, William M., Watkins, Jessica L., Roache, Ryan Christopher, Gamble, Michael John, Downey, Tyler W., Choy, Wendell C.K., Santini, Gregory M.
• Granted Patent: US 10,040,537 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B64C 1/064 Stringers; Longerons
• CPC Class Codes: B64C 1/12 Construction or attachment of skin panels
• CPC Class Codes: B64C 3/182 Stringers, longerons
• CPC Class Codes: B64C 3/187 Ribs
• CPC Class Codes: B64C 3/20 Integral or sandwich constructions
• CPC Class Codes: B64C 3/26 Construction, shape, or attachment of separate skins, e.g. panels
• CPC Class Codes: Y02T 50/40 Weight reduction

Abstract

A wing may include a wing skin, a laminate composite first stringer, a rib, and at least one fastener. A majority of the first stringer may be characterized by a stacked plurality of generally planar plies of reinforcement material structurally joined as a stack to an interior surface of the wing skin and extending generally parallel to the interior surface and a span-wise direction of the wing along a substantial portion of the interior surface. The first stringer may have a generally solid trapezoidal cross section when viewed in a plane that is generally perpendicular to the span-wise direction. The rib may be positioned adjacent the interior surface, and may extend generally perpendicular to the span-wise direction. The trapezoidal cross section may be interfaced with the rib flange. The fastener may extend through the wing skin, the trapezoidal cross section, and the rib flange.

Claims

1. A wing comprising:

a wing skin having an interior surface with a length extending generally parallel to a span-wise direction of the wing;

a laminate composite first stringer a majority of which is characterized by a stacked plurality of generally planar plies of reinforcement material structurally joined as a stack to the interior surface and extending generally parallel to the interior surface and the span-wise direction along a substantial portion of the interior surface, the first stringer having a generally solid trapezoidal cross section when viewed in a plane that is generally perpendicular to the span-wise direction such that a first ply of the stacked plurality of generally planar plies proximal the interior surface has a wider width than a second ply of the stacked plurality of generally planar plies that is further from the interior surface than the first ply;

a rib positioned adjacent the interior surface and extending generally perpendicular to the span-wise direction, the rib including a rib flange and being shaped to define a passageway between the rib flange and the interior surface, wherein the first stringer passes through the passageway such that the trapezoidal cross section is interfaced with the rib flange; and

at least one fastener extending through the wing skin, the trapezoidal cross section, and the rib flange.

2. The wing of claim 1, wherein the stringer extends continuously from one tip of the wing to an opposite tip of the wing relative to an associated fuselage.

3. The wing of claim 1, wherein the passageway has a height extending from the rib flange to the interior surface of the wing skin, the trapezoidal cross section having a height extending in a direction locally normal to the interior surface, the height of the passageway being substantially the same height as the height of the trapezoidal cross section.

4. The wing of claim 3, wherein the height of the passageway extends no more than two inches from the interior surface in the direction locally normal to the interior surface.

5. The wing of claim 1, wherein the wing skin is a lower wing skin of the wing, and has an exterior surface opposite the interior surface, the exterior surface forming a lower exterior portion of the wing.

6. The wing of claim 5, further comprising a plurality of stringers in addition to the first stringer, each of the plurality of stringers being a laminate composite characterized by a respective plurality of stacked generally planar plies of reinforcement material structurally joined to the interior surface and extending generally parallel to the interior surface and the span-wise direction along a substantial portion of the interior surface adjacent the first stringer, wherein the rib flange has a generally ruled lower surface that is interfaced with at least a first subset of stringers of the plurality of stringers in addition to the first stringer such that a majority of the interior surface directly below the lower surface of the rib flange does not contact the lower surface of the rib flange.

7. The wing of claim 6, wherein the rib contacts and is attached to the lower wing skin between the first stringer and a second set of the plurality of stringers by one or more fasteners extending through the lower wing skin and through the rib.

8. The wing of claim 5, wherein the lower wing skin is a laminate composite including a plurality of plies of reinforcement material, the stacked plurality of generally planar plies of the first stringer and the plurality of plies of the lower wing skin being structurally joined to one another by matrix material.

9. The wing of claim 5, wherein the stacked plurality of generally planar plies includes a plurality of layers of tape arranged, with respect to an axis of the trapezoidal cross section that is generally normal to the interior surface, at approximate angles ranging from 0 degrees to 90 degrees, with 0 degrees corresponding to fibers in the associated layer of tape extending generally parallel to the span-wise direction, a greater percentage of layers of tape being arranged at an approximate angle of 0 degrees in an upper portion of the trapezoidal cross section than in a lower portion of the trapezoidal cross section that is disposed between the upper portion and the interior surface.

10. The wing of claim 9, wherein the upper portion and the lower portion include approximately the same number of layers of tape, fibers of the layers of tape being carbon fibers, the matrix material being a polymer.

11. The wing of claim 1, wherein a number of the generally planar plies in the stacked plurality and disposed in the trapezoidal cross section is in a range of 100 to 200 plies.

12. The wing of claim 11, wherein opposing lateral sides of the trapezoidal cross section form respective angles with a local portion of the interior surface in a range of 15 to 60 degrees.

13. A wing for an aircraft, comprising:

a lower wing skin defining a lower exterior surface of the wing;

a plurality of stringers joined to the lower wing skin;

a rib extending generally perpendicular to the stringers, the rib being positioned opposite the lower wing skin relative to the plurality of stringers; and

a fastener extending through the lower wing skin, through a first stringer of the plurality of stringers, and into the rib;

wherein;

the lower wing skin is a laminate composite;

each stringer is a laminate composite including a respective plurality of plies of reinforcement material structurally joined to the lower wing skin by matrix material;

each ply of the plurality of plies is generally locally parallel to the lower exterior surface of the wing; and

each stringer has a cross section extending in a plane substantially parallel to and aligned with the rib, each cross section being generally tapered and solid, with a width that decreases as measured locally parallel to the lower exterior surface of the wing, when progressing from adjacent the lower wing skin to adjacent the rib, and the plurality of plies filling a substantial portion of the respective cross section.

14. The wing of claim 13, wherein each plurality of plies includes a plurality of layers of tape arranged, with respect to an axis locally perpendicular to the exterior surface, at a plurality of different angles, with an approximately 0 degree angle corresponding to fibers of the associated layer of tape extending generally parallel to a span-wise direction of the wing, a greater percentage of layers of tape being arranged at an angle of approximately 0 degrees in an upper portion of the associated cross section than in a lower portion of the associated cross section.

15. The wing of claim 14, wherein the upper portion and the lower portion include approximately the same number of layers of tape.

16. The wing of claim 15, wherein the upper portion and the lower portion each include layers of tape arranged at approximate angles of 0 degrees, −

45 degrees, 90 degrees, and 45 degrees.

17. The wing of claim 16, wherein the cross section of the first stringer is a trapezoidal cross section a majority of which is composed of fibers of associated layers of tape.

18. A method of stiffening a wing, comprising the steps of:

positioning a rib adjacent an interior surface of a laminate composite lower wing skin of the wing such that the rib is oriented generally perpendicular to a span-wise direction of the wing, wherein the wing includes a laminate composite stringer formed by a tapered stack of generally planar plies of reinforcement material structurally joined to the interior surface and extending generally parallel to the interior surface and to the span-wise direction along a substantial portion of the interior surface; and

operatively coupling the rib to the lower wing skin and the stringer at least in part by extending at least one fastener through the lower wing skin, through the tapered stack of generally planar plies, and through a flange of the rib, thereby stiffening the wing.

19. The method of claim 18, wherein the tapered stack has a generally solid trapezoidal cross section in a plane generally perpendicular to the span-wise direction, at least a majority of the solid trapezoidal cross section being characterized by the planar plies of reinforcement material, an aperture being formed through the lower wing skin and the trapezoidal cross section, and the extending step involves disposing the at least one fastener in the aperture and inserting the fastener into the flange of the rib.

20. The method of claim 18, wherein the positioning step further includes disposing an adjacent portion of the flange on the interior surface adjacent the tapered stack, and the operatively coupling step further includes fastening the adjacent portion of the flange to the interior surface by extending at least one other fastener through the lower wing skin and the adjacent portion of the flange.