Stiffened panels

Patent metadata

Field	Value
Publication number	US-10814566-B2
Application number	US-201715702142-A
Country	US
Kind code	B2
Filing date	Sep 12, 2017
Priority date	Sep 12, 2017
Publication date	Oct 27, 2020
Grant date	Oct 27, 2020

Abstract

A method for fabricating a stiffened panel. Layers of composite material are placed on a surface of an inner-mold-line tool having protrusions that extend from the surface of the inner-mold-line tool. The layers of composite material laid-up on the surface of the inner-mold-line tool are compacted to form compacted layers of composite material. The compacted layers of composite material are cured to form an inner-mold-line layer having corresponding protrusions. The inner-mold-line layer is joined to an outer-mold-line layer.

First claim

What is claimed is:

1. A method for fabricating a stiffened panel, the method comprising:
placing layers of composite material on a surface of an inner-mold-line tool having protrusions that extend from the surface of the inner-mold-line tool;
compacting the layers of composite material laid-up on the surface of the inner-mold-line tool to form compacted layers of composite material;
curing the compacted layers of composite material to form an inner-mold-line layer having corresponding protrusions; and
melt-bonding the inner-mold-line layer to an outer-mold-line layer with a bonding tool placed on the inner-mold-line layer that applies a pressure at bond locations between the inner-mold-line layer and the outer-mold-line layer, wherein the bonding tool comprises a plate with protrusions that match depressions in the inner-mold-line layer.

2. The method of claim 1 , wherein compacting the layers of composite material laid-up on the surface of the inner-mold-line tool to form compacted layers of composite material comprises:
compacting the layers of composite material laid-up on the surface of the inner-mold-line tool using an intensifier to form compacted layers of composite material, wherein the intensifier has a symmetrical shape of the inner-mold-line tool on which the layers of composite material are laid-up.

3. The method of claim 1 , wherein melt-bonding the inner-mold-line layer to the outer-mold-line layer comprises:
bonding the inner-mold-line layer to the outer-mold-line layer using an adhesive.

4. The method of claim 1 , wherein placing the layers of composite material on the surface of the inner-mold-line tool having the protrusions that extend from the surface of the inner-mold-line tool comprises:
laying-up a first portion of the layers of composite material over the protrusions; and
laying-up a second portion of the layers of composite material on the inner-mold-line tool, wherein the second portion of the layers of composite material has openings corresponding to the protrusions.

5. The method of claim 1 , wherein placing the layers of composite material on the surface of the inner-mold-line tool having protrusions that extend from the surface of the inner-mold-line tool comprises:
interleaving continuous plies with doubler plies and protrusion plies.

6. The method of claim 1 , wherein the outer-mold-line layer is substantially smooth.

7. The method of claim 1 , wherein the stiffened panel is an integrally stiffened thermoplastic panel.

8. The method of claim 1 , wherein the composite material comprises a mixture of structural fibers and thermoplastic fibers with or without a binder or a binding agent, wherein the thermoplastic fibers, when melted and consolidated, form a matrix to form the stiffened panel in a form of a thermoplastic panel.

9. The method of claim 1 , further comprising infusing the compacted layers of composite material with a thermosetting matrix resin.

10. The method of claim 1 , wherein the locations where inner-mold-line layer and outer-mold-line layer contact each other comprise depressions and a surrounding edge of inner-mold-line layer.

11. A method for fabricating a stiffened panel, the method comprising:
placing layers of composite material on a surface of an inner-mold-line tool having protrusions that extend from the surface of the inner-mold-line tool, wherein the layers comprise at least a first layer and a second layer, and wherein the first layer and the second layer have different orientations of the composite material;
compacting the layers of composite material laid-up on the surface of the inner-mold-line tool to form compacted layers of composite material;
curing the compacted layers of composite material to form an inner-mold-line layer having corresponding protrusions; and
melt-bonding the inner-mold-line layer to an outer-mold-line layer with a bonding tool placed on the inner-mold-line layer that applies a pressure at bond locations between the inner-mold-line layer and the outer-mold-line layer, wherein the bonding tool comprises a plate with protrusions that match depressions in the inner-mold-line layer.

12. The method of claim 11 , wherein compacting the layers of composite material laid-up on the surface of the inner-mold-line tool to form compacted layers of composite material comprises:
compacting the layers of composite material laid-up on the surface of the inner-mold-line tool using an intensifier to form compacted layers of composite material, wherein the intensifier has a symmetrical shape of the inner-mold-line tool on which the layers of composite material are laid-up.

13. The method of claim 11 , wherein melt-bonding the inner-mold-line layer to the outer-mold-line layer comprises:
bonding the inner-mold-line layer to the outer-mold-line layer using an adhesive.

14. The method of claim 11 , wherein placing the layers of composite material on the surface of the inner-mold-line tool having the protrusions that extend from the surface of the inner-mold-line tool comprises:
laying-up a first portion of the layers of composite material over the protrusions; and
laying-up a second portion of the layers of composite material on the inner-mold-line tool, wherein the second portion of the layers of composite material has openings corresponding to the protrusions.

15. The method of claim 11 , wherein placing the layers of composite material on the surface of the inner-mold-line tool having protrusions that extend from the surface of the inner-mold-line tool comprises:
interleaving continuous plies with doubler plies and protrusion plies.

16. The method of claim 11 , wherein the outer-mold-line layer is substantially smooth.

17. The method of claim 11 , wherein the stiffened panel is an integrally stiffened thermoplastic panel.

18. The method of claim 11 , wherein the locations where inner-mold-line layer and outer-mold-line layer contact each other comprise depressions and a surrounding edge of inner-mold-line layer.

19. The method of claim 11 , further comprising infusing the compacted layers of composite material with a thermosetting matrix resin.

20. The method of claim 11 , wherein the composite material comprises a mixture of structural fibers and thermoplastic fibers with or without a binder or a binding agent, wherein the thermoplastic fibers, when melted and consolidated, form a matrix to form the stiffened panel in a form of a thermoplastic panel.

Assignees

• Boeing Co

Inventors

• Tsotsis Thomas Karl
• Litchard Iii Roscoe C

Classifications

• B29C2043/147

  by compressing after the laying of further material · CPC title

• B29D99/0014

  provided with ridges or ribs, e.g. joined ribs · CPC title

• B29C2043/148

  using different moulds · CPC title

• B29C70/70

  Completely encapsulating inserts {(B29C70/86 takes precedence)} · CPC title

• B32B27/06

  as the main or only constituent of a layer, {which is} next to another layer of {the same or of} a {different material (next to a layer of a particular substance B32B9/045; next to a bituminous or tarry layer B32B11/046; next to a water setting substance layer B32B13/12; next to a metal layer B32B15/08; next to a glass layer B32B17/10; next to a layer formed of natural mineral fibres or particles B32B19/045; next to a wood layer B32B21/08; next to a cellulosic plastic layer B32B23/08; next to a natural or synthetic rubber layer B32B25/08)} · CPC title