Stiffened Panels

Patent metadata

Field	Value
Publication number	US-2019077093-A1
Application number	US-201715702142-A
Country	US
Kind code	A1
Filing date	Sep 12, 2017
Priority date	Sep 12, 2017
Publication date	Mar 14, 2019
Grant date	—

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 joining the inner-mold-line layer to an outer-mold-line layer.

2 . The method of claim 1 , 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 joining 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 a bonding tool that applies a pressure at bond locations between the inner-mold-line layer and the outer-mold-line layer.

4 . The method of claim 1 , wherein joining the inner-mold-line layer to the outer-mold-line layer comprises:
melt-bonding the inner-mold-line layer to the outer-mold-line layer.

5 . The method of claim 1 , wherein joining 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.

6 . 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.

7 . 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.

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

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

10 . 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.

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

12 . A method for manufacturing a stiffened thermoplastic panel, the method comprising:
compression forming an inner-mold-line skin from a thermoplastic composite material having ridges and valleys; compression forming an outer-mold-line skin from the thermoplastic composite material, wherein the outer-mold-line skin is substantially smooth; and melt-bonding the inner-mold-line skin and the outer-mold-line skin together.

13 . A manufacturing system for forming a stiffened panel, wherein the manufacturing system comprises:
a control system in the manufacturing system, wherein the control system is configured to control the manufacturing system to place 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; compact the layers of composite material laid-up on the surface of the inner-mold-line tool to form compacted layers of composite material; cure the compacted layers of composite material to form an inner-mold-line layer having corresponding protrusions; and bond the inner-mold-line layer to an outer-mold-line layer.

14 . The manufacturing system of claim 13 further comprising:
the manufacturing system controlled by the control system.

15 . The manufacturing system of claim 13 , wherein the control system controls the manufacturing system to manufacture the stiffened panel by assigning tasks to human operators of manufacturing equipment to manufacture the stiffened panel.

16 . The manufacturing system of claim 13 , 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, the control system controls the manufacturing system to compact 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, and wherein the intensifier has a symmetrical shape of the inner-mold-line tool on which the layers of composite material are laid-up.

17 . The manufacturing system of claim 13 , wherein the control system is configured to control the manufacturing system to bond the inner-mold-line layer to the outer-mold-line layer using a bonding tool that applies a pressure at bond locations between the inner-mold-line layer and the outer-mold-line layer.

18 . The manufacturing system of claim 13 , wherein the control system is configured to control the manufacturing system to melt-bond the inner-mold-line layer to the outer-mold-line layer.

19 . The manufacturing system of claim 13 , wherein the control system is configured to control the manufacturing system to bond the inner-mold-line layer to the outer-mold-line layer using an adhesive to form the stiffened panel.

20 . The manufacturing system of claim 13 , wherein in controlling the manufacturing system to place 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, the control system is configured to control the manufacturing system to lay-up a first portion of the layers of composite material over the protrusions and lay-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.

Assignees

• Boeing Co

Inventors

• Tsotsis Thomas Karl
• Litchard Iii Roscoe C

Classifications

• B29D99/0014

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

• B29C70/34 Primary

  and shaping or impregnating by compression {, i.e. combined with compressing after the lay-up operation} · CPC title

• B29C2043/148

  using different moulds · CPC title

• B29L2031/3076

  Aircrafts (blades, propellers B29L2031/08) · CPC title

• B32B3/08

  characterised by added members at particular parts {(layer formed of separate pieces of material which are juxtaposed side-by-side B32B3/14, B32B3/18)} · CPC title