Apparatus and methods for forming composite stiffeners and reinforcing structures

• US 20050056362A1
• Filed: 07/30/2004
• Published: 03/17/2005
• Est. Priority Date: 08/01/2003
• Status: Active Grant

• Current Assignee: Northrop Grumman Systems Corporation (Northrop Grumman Corporation)
• Original Assignee: Alliant Techsystems Incorporated (Northrop Grumman Corporation)
• Inventors: Rosevear, Todd A., Harvey, James L., Benson, Vernon M., Olschewski, Timothy, Slack, Jason, Roman, Mark
• Granted Patent: US 7,513,769 B2
• Time in Patent Office: Days
• US Class Current: 156/163
• CPC Class Codes: B29C 70/388 Tape placement heads, e.g. component parts, details or accessories
• CPC Class Codes: B29C 70/504 using rollers or pressure bands for corrugating B29C53/22
• CPC Class Codes: B29C 70/541 Positioning reinforcements in a mould, e.g. using clamping means for the reinforcement positioning inserts in moulds B29C33/12; lay-up on a mould B29C70/30
• CPC Class Codes: B29C 70/545 Perforating, cutting or machining during or after moulding
• CPC Class Codes: B29K 2307/00 Use of elements other than metals as reinforcement
• CPC Class Codes: B29K 2901/10 Thermosetting resins
• CPC Class Codes: B29L 2031/003 having a profiled transverse cross-section
• CPC Class Codes: Y02T 50/40 Weight reduction
• CPC Class Codes: Y10T 156/1002 with permanent bending or reshaping or surface deformation of self sustaining lamina
• CPC Class Codes: Y10T 156/1028 by bending, drawing or stretch forming sheet to assume shape of configured lamina while in contact therewith
• CPC Class Codes: Y10T 156/1031 with preshaping of lamina
• CPC Class Codes: Y10T 428/24124 Fibers
• CPC Class Codes: Y10T 428/24628 Nonplanar uniform thickness material
• CPC Class Codes: Y10T 428/249948 Fiber is precoated
• CPC Class Codes: Y10T 428/24995 Two or more layers

Abstract

A method and apparatus are provided for forming elongated composite structural members with a desired cross-sectional geometry as taken transverse to the length of the member. An apparatus may include a base with a substantially elongated mandrel mounted thereon. One or more rollers configured to at least partially complementarily engage the mandrel are configured to roll over and press one or more plies of composite material onto the mandrel. The mandrel may be disposed on a rotary table and configured to exhibit a curved elongated geometry to form at least partially curved or arcuate elongated members. The present invention enables the formation of elongated structural members from resin impregnated materials while maintaining the materials in a substantially uncured state. The formed members may then be cocured with a skin or other composite structure.

Claims

1. A method of forming an elongated composite structural member, the method comprising:

providing a substantially elongated mandrel having an exterior surface exhibiting a desired geometry;

laying up a first ply of preimpregnated fiber reinforced material over the mandrel;

applying a force to the first ply to establish a desired amount of tension within the first ply;

pressing the first ply onto the mandrel in a conformal manner including passing at least one roller over the mandrel and the first ply while maintaining the desired amount of tension within the first ply, the at least one roller being at least partially complementary in shape with the mandrel.

2. The method according to claim 1, further comprising laying up a second ply of material over the first ply of material, applying a force to the second ply to establish a desired amount of tension within the second ply, and pressing the second ply onto the first ply in a conformal manner with the at least one roller while maintaining the desired amount of tension within the second ply.

3. The method according to claim 2, wherein pressing the second ply onto the first ply includes consolidating the first ply and the second ply.

4. The method according to claim 3, further comprising maintaining the first ply and the second ply in a substantially uncured state.

5. The method according to claim 2, wherein laying up a first ply of preimpregnated fiber material over the mandrel includes defining the first ply to exhibit a first fiber orientation and wherein laying up a second ply of material over the first ply of material includes defining the second ply of material to exhibit a second fiber orientation different from the first fiber orientation.

6. The method according to claim 2, wherein laying up a first ply of preimpregnated fiber material over the mandrel includes defining the first ply to exhibit a first width and wherein laying up a second ply of material over the first ply of material includes defining the second ply of material to exhibit a second width different from the first width.

7. The method according to claim 1, wherein passing the at least one roller over the mandrel and the first ply includes sequentially passing a plurality of rollers over the mandrel and the first ply.

8. The method according to claim 7, further comprising configuring the plurality of rollers such that a first roller partially complementarily engages the mandrel over a first surface area of the mandrel and such that a second roller complementarily engages the mandrel over a second surface area of the mandrel.

9. The method according to claim 1, further comprising forming the mandrel to exhibit an arcuate portion along at least one section of a length thereof.

10. The method according to claim 9, wherein applying a force to the first ply to establish a desired amount of tension within the first ply includes stretching a portion of the first ply along an area adjacent a first lateral edge of the first ply.

11. The method according to claim 10, wherein applying a force to the first ply to establish a desired amount of tension within the first ply includes preventing wrinkles from forming in the first ply along an area adjacent a second, opposing lateral edge of the first ply.

12. The method according to claim 10, further comprising applying a desired amount of heat to at least an area of the first ply adjacent the first lateral edge.

13. The method according to claim 9, wherein applying a force to the first ply to establish a desired amount of tension within the first ply includes applying a force in a direction that is substantially tangent to a radius of curvature of the mandrel at a location where the first ply is being laid up on the mandrel.

14. The method according to claim 9, wherein applying a force to the first ply to establish a desired amount of tension within the first ply includes applying a force in a direction that is approximately 89°

to 91°

relative to a radial centerline passing through the arcuate portion.

15. The method according to claim 1, further comprising coupling the mandrel to a rotary table, coupling the at least one roller to a carriage assembly, and wherein passing at least one roller over the mandrel and the first ply includes rotating the rotary table and the mandrel beneath the carriage assembly.

16. The method according to claim 15, further comprising tracking the mandrel with the carriage assembly while the rotary table rotates including displacing the carriage assembly in a radial direction relative to the rotary table.

17. The method according to claim 1, further comprising forming the elongated composite structural member to substantially exhibit a cross-sectional geometry of a hat as taken transverse to a length of the elongated member.

18. The method according to claim 1, further comprising forming the elongated composite structural member to substantially exhibit a cross-sectional geometry of at least one C-shape as taken transverse to a length of the elongated member.

19. The method according to claim 1, further comprising forming the elongated composite structural member to substantially exhibit a cross-sectional geometry of at least one angle as taken transverse to a length of the elongated member.

20. The method according to claim 1, wherein laying up a first ply of preimpregnated fiber reinforced material includes laying up a first ply of fiber reinforced material impregnated with a thermosetting resin.

21. An apparatus for forming elongated composite structural members comprising:

a table configured to rotate about a defined axis;

at least one mandrel mounted on the table, the at least one mandrel exhibiting a substantially elongated geometry including at least one substantially arcuate portion;

a carriage assembly disposed adjacent the table;

at least one roller exhibiting a geometry configured to at least partially complementarily engage the at least one mandrel and the at least one roller thereover, the at least one roller coupled with the carriage assembly;

at least one material dispensing device configured to dispense at least one ply of material onto the at least one mandrel; and

at least one force applying mechanism located and configured to apply a desired force to the at least one ply and induce a desired amount of tension therein while the material is on the at least one mandrel and while the at least one roller passes over the at least one ply disposed on the at least one mandrel.

22. The apparatus of claim 21, wherein the at least one roller comprises a plurality of rollers coupled with the carriage assembly.

23. The apparatus of claim 21, wherein the at least one material dispensing device is configured to dispense a first ply of material exhibiting a first width and at least a second ply of material exhibiting a second width different than the first width.

24. The apparatus of claim 21, wherein the at least one roller and the at least one mandrel are complementarily configured to form an elongated composite structural member substantially exhibiting a cross-sectional geometry of a hat as taken transversely to a length thereof.

25. The apparatus of claim 21, wherein the at least one roller and the at least one mandrel are complementarily configured to form an elongated composite structural member substantially exhibiting a cross-sectional geometry of at least one C-shape as taken transversely to a length thereof.

26. The apparatus of claim 21, wherein the at least one roller and the at least one mandrel are complementarily configured to form an elongated composite structural member substantially exhibiting a cross-sectional geometry of at least one angle as taken transversely to a length thereof.

27. The apparatus of claim 21, wherein the at least one roller and the at least one mandrel are complementarily configured to form an elongated composite structural member substantially exhibiting a cross-sectional geometry including at least one arcuate section taken transversely to a length thereof.

28. The apparatus of claim 21, further comprising at least one actuator operably coupled between the carriage assembly and the at least one roller configured to apply a force to the at least one mandrel via the at least one roller.

29. The apparatus of claim 28, wherein the at least one actuator includes a hydraulic system.

30. The apparatus of claim 28, wherein the at least one actuator includes a pneumatic system.

31. The apparatus of claim 21, wherein the at least one mandrel includes a plurality of mandrels.

32. The apparatus of claim 21, wherein the carriage assembly is configured to be displaced in a radial direction relative to the defined axis.

33. The apparatus of claim 32, wherein the at least one roller is configured to track a radial deviation of the at least one mandrel while the table rotates about the defined axis.

34. The apparatus of claim 21, further comprising a heating device configured and oriented to heat at least a portion of the at least one ply of material.

35. The apparatus of claim 21, wherein the at least one material dispensing device further comprises:

at least one supply roller having a supply of material to be dispensed as the at least one ply of material;

at least one feeding device to motivate the at least one ply of material from the at least one supply roller to the at least one mandrel; and

at least one tack roller configured to press the at least one ply of material against a portion of the at least one mandrel.

36. The apparatus of claim 35, wherein the at least one material dispensing device further comprises at least one cutting device located and configured to cut the at least one ply of material.

37. The apparatus of claim 36, wherein the at least one cutting device is configured to cut the at least one ply of material to a desired width.

38. The apparatus of claim 36, wherein the at least one cutting device is configured to cut the at least one ply of material to a desired length.

39. The apparatus of claim 35, further comprising a controller operably coupled with the apparatus and configured to control the at least one feeding device.

40. The apparatus of claim 21, further comprising a controller operably coupled with the apparatus and configured to control the at least one force applying mechanism.

41. The apparatus of claim 21, further comprising a controller operably coupled with the apparatus and configured to control the rotation of the table.

42. The apparatus of claim 41, wherein the controller includes a processor, a memory device, at least one input device and at least one output device.

43. The apparatus of claim 21, wherein the at least one force applying mechanism is located and configured to apply the desired force to the at least one ply in a direction that is substantially tangent to the at least one mandrel at a location where the at least one ply is disposed on the at least one mandrel.

44. The apparatus of claim 21, wherein the at least one force applying mechanism is located and configured to apply the desired force to the at least one ply at an angle of approximately 89°

to 90°

relative to a radial centerline passing through the defined axis and through the at least one mandrel at a location where the at least one ply is disposed on the at least one mandrel.