Method of forming a truss reinforced foam core sandwich structure

• US 5,624,622 A
• Filed: 02/07/1996
• Issued: 04/29/1997
• Est. Priority Date: 05/04/1993
• Status: Expired due to Term

• Current Assignee: Foster-Miller Incorporated (Thermo Fisher Scientific Incorporated)
• Original Assignee: Foster-Miller Incorporated (Thermo Fisher Scientific Incorporated)
• Inventors: Campbell, Thomas G., Boyce, Joseph S., Freitas, Glenn A.
• Primary Examiner(s): Kuhns, Allan R.
• Application Number:
  US08/598,194
• Time in Patent Office: 447 Days
• Field of Search: 264/45.8, 264/257, 264/321, 264/258, 29/432, 29/432.1
• US Class Current: 264/258
• CPC Class Codes: B29C 44/569 Shaping and joining components with different densities or hardness
• CPC Class Codes: B29C 70/08 comprising combinations of different forms of fibrous reinforcements incorporated in matrix material, forming one or more layers, and with or without non-reinforced layers
• CPC Class Codes: B29C 70/083 Combinations of continuous fibres or fibrous profiled structures oriented in one direction and reinforcements forming a two dimensional structure, e.g. mats B29D24/00, B29D99/001 take precedence
• CPC Class Codes: B32B 2305/022 Foam
• CPC Class Codes: B32B 2305/08 Reinforcements
• CPC Class Codes: B32B 2305/18 Fabrics, textiles
• CPC Class Codes: B32B 2307/542 Shear strength
• CPC Class Codes: B32B 2607/00 Walls, panels
• CPC Class Codes: B32B 38/08 Impregnating
• CPC Class Codes: B32B 5/18 characterised by features of a layer of foamed material
• CPC Class Codes: E04C 2/22 reinforced E04C2/205 takes precedence
• CPC Class Codes: E04C 2/296 composed of insulating material and non-metallic or unspecified sheet-material E04C2/288 takes precedence
• CPC Class Codes: Y10T 29/49833 Punching, piercing or reaming part by surface of second part
• CPC Class Codes: Y10T 29/49835 with shaping
• CPC Class Codes: Y10T 428/233 Foamed or expanded material encased
• CPC Class Codes: Y10T 428/23914 Interlaminar
• CPC Class Codes: Y10T 428/24116 Oblique to direction of web
• CPC Class Codes: Y10T 428/24174 including sheet or component perpendicular to plane of web or sheet
• CPC Class Codes: Y10T 428/249923 Including interlaminar mechanical fastener
• CPC Class Codes: Y10T 428/24996 With internal element bridging layers, nonplanar interface between layers, or intermediate layer of commingled adjacent foam layers
• CPC Class Codes: Y10T 428/249986 : Void-containing component contains also a solid fiber or solid particle

Abstract

A reinforced foam core sandwich structure including opposing face sheets, a foam core therebetween, and tow members encapsulated within the foam core and extending between the opposing face sheets forming a support structure within the foam core between the face sheets.

Claims

1. A method of fabricating a reinforced foam core sandwich structure comprising:

disposing a plurality of discrete supporting tow members within a foam core, at least a number of said tow members each extending between the outer surfaces of said foam core;

assembling face sheets on the opposing faces of said foam core; and

compressing said foam core to drive said tow members into said face sheets.

2. The method of claim 1 in which said foam core includes outer compactable layers of a first density and an interior layer of a second density greater than said first density.

3. The method of claim 1 in which said face sheets are dry fabric and said method further includes wetting said fabric with resin after compressing said foam core and then curing said face sheets.

4. The method of claim 1 in which said face sheets are a prepreg material and said method further includes curing said structure after compressing said foam core.

5. The method of claim 1 in which said tow members are rigid rods of multifilamentary bundles preimpregnated with a resin and then cured.

6. The method of claim 1 in which a number of said tow members form a shear bearing truss structure within said foam core for reinforcing the shear strength of the sandwich structure.

7. The method of claim 6 in which said truss structure includes a number of X-braced chords.

8. The method of claim 6 in which a number of said tow members are disposed perpendicularly between said face sheets.

9. The method of claim 1 in which compressing said foam core includes applying pressure to said face sheets.