Foam mandrel assembly

Patent metadata

Field	Value
Publication number	US-10926435-B2
Application number	US-201715649162-A
Country	US
Kind code	B2
Filing date	Jul 13, 2017
Priority date	May 3, 2017
Publication date	Feb 23, 2021
Grant date	Feb 23, 2021

Abstract

An illustrative embodiment of the present disclosure provides a method of manufacturing a composite structure. A composite material having a closed cross-section or a partially closed cross-section is cured to form the composite structure, wherein the composite material is in contact with a foam mandrel assembly when curing begins. A supportive foam mandrel in the foam mandrel assembly is collapsed during curing.

First claim

What is claimed is:

1. A method of manufacturing a composite structure, the method comprising:
forming a compacted stringer package comprising a composite charge, a first radius filler, a second radius filler, and a foam mandrel assembly, wherein the compacted stringer package is sufficiently rigid to transport compacted stringer package without a rigid base, wherein forming the compacted stringer package comprises:
placing the composite charge over the foam mandrel assembly, the first radius filler, and the second radius filler;
applying mechanical pressure to shape the composite charge to the foam mandrel assembly and the rigid base to form a stringer layup; and
applying vacuum pressure to the stringer layup to form the compacted stringer package;

transporting the compacted stringer package to a cure tool, wherein the compacted stringer package is transported to the cure tool without the rigid base;
placing the compacted stringer package onto the cure tool;
curing composite material of the compacted stringer package at an elevated temperature to form the composite structure on the cure tool; and
collapsing a supportive foam mandrel within the foam mandrel assembly during curing, wherein collapsing the supportive foam mandrel comprises drawing a vacuum within the foam mandrel assembly to collapse the supportive foam mandrel within the foam mandrel assembly during curing.

2. The method of claim 1 , wherein collapsing the supportive foam mandrel comprises the supportive foam mandrel going from a first size to a second size without decomposing, wherein the second size is smaller than the first size.

3. The method of claim 1 further comprising:
pulling the foam mandrel assembly with collapsed foam mandrel from the composite structure after curing.

4. The method of claim 1 , wherein the supportive foam mandrel is an open cell foam.

5. The method of claim 1 , wherein the vacuum is applied so that the supportive foam mandrel collapses after pressure equalizes in a resin area of the compacted stringer package.

6. The method of claim 1 , wherein material of the supportive foam mandrel softens at a temperature above a pressure differential temperature at which pressure differentials within the compacted stringer package being cured are substantially equalized, and wherein the temperature is below a maximum temperature of a cure cycle.

7. The method of claim 1 , wherein the supportive foam mandrel is formed of one of polyethylene terephthalate, polyphenylsulfone, or polymethacrylimide.

8. A method of manufacturing a composite structure, the method comprising:
forming a compacted stringer package comprising a foam mandrel assembly, wherein a pre-preg composite material is in the compacted stringer package and wherein the pre-preg composite material has a closed cross-section or a partially closed cross-section wherein the compacted stringer package is sufficiently rigid to transport compacted stringer package without a rigid base, wherein forming the compacted stringer package comprises:
placing a composite charge over the foam mandrel assembly, a first radius filler, and a second radius filler;
applying mechanical pressure to shape the composite charge to the foam mandrel assembly and the rigid base to form a stringer layup; and
applying vacuum pressure to the stringer layup to form the compacted stringer package;

transporting the compacted stringer package to a cure tool, wherein the compacted stringer package is transported to the cure tool without the rigid base;
curing the pre-preg composite material having the closed cross-section or the partially closed cross-section to form the composite structure on the cure tool, wherein the pre-preg composite material is in contact with the foam mandrel assembly when curing begins; and
collapsing a supportive foam mandrel in the foam mandrel assembly during curing, wherein a material of the supportive foam mandrel softens at a temperature above a pressure differential temperature at which pressure differentials within a part the compacted stringer package being cured are substantially equalized, and wherein the temperature is below a maximum temperature of a cure cycle.

9. The method of claim 8 further comprising:
placing the pre-preg composite material onto the cure tool; and
placing a number of cauls over the pre-preg composite material on the cure tool.

10. The method of claim 9 , wherein the supportive foam mandrel is an open cell foam.

11. The method of claim 8 , wherein collapsing the supportive foam mandrel comprises applying a vacuum to the supportive foam mandrel.

12. The method of claim 8 further comprising:
curing the pre-preg composite material of the compacted stringer package at an elevated temperature to form the composite structure.

13. A method of manufacturing a composite structure, the method comprising:
forming a compacted stringer package comprising a composite charge, a first radius filler, a second radius filler, and a foam mandrel assembly, wherein the compacted stringer package is sufficiently rigid to transport compacted stringer package without a rigid base, wherein forming the compacted stringer package comprises:
placing the composite charge over the foam mandrel assembly, the first radius filler, and the second radius filler;
applying mechanical pressure to shape the composite charge to the foam mandrel assembly and the rigid base to form a stringer layup; and
applying vacuum pressure to the stringer layup to form the compacted stringer package;

transporting the compacted stringer package to a cure tool, wherein the compacted stringer package is transported to the cure tool without the rigid base;
placing the compacted stringer package onto the cure tool;
curing composite material of the compacted stringer package at an elevated temperature to form the composite structure on the cure tool; and
collapsing a supportive foam mandrel within the foam mandrel assembly during curing, wherein collapsing the supportive foam mandrel relies on at least one of an elevated temperature or an elevated pressure.

Assignees

• Boeing Co

Inventors

• Heath Richard E
• Modin Andrew Elmer
• Prause Richard Alexander

Classifications

• B29C70/30 Primary

  Shaping by lay-up, i.e. applying fibres, tape or broadsheet on a mould, former or core; Shaping by spray-up, i.e. spraying of fibres on a mould, former or core · CPC title

• B29C43/02 Primary

  of articles of definite length, i.e. discrete articles {(B29C35/0227 takes precedence)} · CPC title

• B29D99/0003

  Producing profiled members, e.g. beams · CPC title

• B29C70/541

  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 title

• B64F5/10 Primary

  Manufacturing or assembling aircraft, e.g. jigs therefor · CPC title