Method of fabricating a tank having integral restraining elements

• US 9,266,619 B2
• Filed: 04/21/2014
• Issued: 02/23/2016
• Est. Priority Date: 06/23/2008
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Childress, James J., Perron, Dan
• Primary Examiner(s): Goff, John
• Application Number:
  US14/257,274
• Publication Number:
  US 20140223744A1
• Time in Patent Office: 673 Days
• US Class Current: 1/1
• CPC Class Codes: B23P 11/00 Connecting or disconnecting metal parts or objects by metal-working techniques not otherwise provided for connecting sheet metal or metal tubes, rods or profiles B21D39/00; riveting B21J; soldering, unsoldering, welding B23K; hand tools for connecting wire or strip B25B25/00; connecting metal parts by adhesives F16B11/00
• CPC Class Codes: B60K 15/03 Fuel tanks chassis frame comprising fluid storage compartment B62D21/16 ; Details of the fuel feeding system related to the fuel tank F02M37/0076
• CPC Class Codes: B60K 2015/03046 made from more than one layer
• CPC Class Codes: B60K 2015/03065 with material filled between the walls
• CPC Class Codes: B60K 2015/03407 to protect tanks against projectiles
• CPC Class Codes: B64D 2037/325 Fuel tanks with provisions for reduction hydraulic ram shocks due to projectile impacts
• CPC Class Codes: B64D 37/08 Internal partitioning
• CPC Class Codes: B64D 37/32 Safety measures not otherwise provided for, e.g. preventing explosive conditions extinguishing or preventing fires in aircraft A62C
• CPC Class Codes: F17C 1/02 involving reinforcing arrangements F17C1/14, F17C1/16 take precedence
• CPC Class Codes: F17C 1/08 Integral reinforcements, e.g. ribs
• CPC Class Codes: Y02T 50/40 Weight reduction
• CPC Class Codes: Y10T 29/49622 Vehicular structural member making
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

A tank and associated fabrication method are provided which may limit the damage otherwise occasioned by the impact of a ballistic projectile. The tank may include a wall assembly defined between outer and inner walls and a plurality of restraining elements that extend between the walls. The restraining elements may be formed to have a plurality of layers of material that form not only the restraining element, but also portions of the inner and/or outer walls. For example, the tank may include a plurality of cells positioned adjacent to one another with each cell forming portions of two adjacent restraining elements and portions of the inner and/or outer walls. A corresponding method for fabricating a tank including a wall assembly having a plurality of restraining elements is also provided.

Claims

1. A method of fabricating a tank comprising:

forming a plurality of cells, each cell comprising a plurality of layers of material that extend about and define each cell;

positioning the plurality of cells with respect to one another;

positioning inner and outer face sheets on opposite sides of the plurality of cells, wherein the inner and outer face sheets that are positioned on opposite sides of the plurality of cells are formed of different types of materials; and

curing the inner and outer face sheets and the plurality of layers of material that form each of the plurality of cells to thereby form a wall assembly having (i) inner and outer walls that are each formed by a respective face sheet and a portion of the plurality of cells and (ii) a plurality of restraining elements extending between the inner and outer walls with each restraining element formed by a portion of a cell;

wherein the wall assembly defines an inlet through the outer wall comprised of the outer face sheet and the plurality of layers of material that comprise a respective cell opening into a volume defined between the inner and outer walls in order to permit a pressurized gas to be introduced within the wall assembly, and

wherein the wall assembly further defines an inlet through the inner wall comprised of the inner face sheet and the plurality of layers of material that comprise a respective cell.

2. A method according to claim 1 wherein forming the plurality of cells comprises wrapping a plurality of layers of material about a tool to form a respective cell, wherein the layers of material remain wrapped about a respective tool while positioning the plurality of cells and the inner and outer face sheets and while curing the inner and outer face sheets and the layers of material that form the cells, and wherein the method further comprises removing each tool following curing of the inner and outer face sheets and the layers of material that form the cells.

3. A method according to claim 1 wherein the plurality of cells define at least one opening, and wherein positioning the cells comprises positioning the cells adjacent one another such that the openings defined by adjacent cells are aligned in order to correspondingly define an opening in the respective restraining element.

4. A method according to claim 1 further comprising positioning a plurality of noodles between respective pairs of adjacent cells prior to positioning the inner and outer face sheets.

5. A method according to claim 1 wherein curing the inner and outer face sheets and the layers of material that form the cells comprises subjecting the inner and outer face sheets and the layers of material that form the cells to a reduced pressure and co-curing the inner and outer face sheets and the layers of material that form the cells.

6. A method according to claim 1 wherein positioning the plurality of cells comprises positioning the plurality of cells such that each layer extends from the inner wall to the outer wall so as to form a portion of two restraining elements and a portion of at least one of the inner and outer walls extending between the two restraining elements.

7. A method according to claim 1 wherein positioning inner and outer face sheets comprises positioning the inner and outer face sheets on opposite sides of the cells such that the plurality of cells are positioned between the inner and outer face sheets.

8. A method according to claim 1 wherein forming a plurality of cells comprises forming a complete loop with at least some of the layers of material so as to form portions of two restraining elements and portions of both the inner and outer walls that extend between the two restraining elements.

9. A method according to claim 1 wherein at least a portion of at least one restraining element that extends between the inner and outer walls defines an opening therethrough.

10. A method according to claim 1 wherein forming a plurality of cells comprises forming the plurality of cells with a plurality of plies of pre-impregnated composite material.

11. A method according to claim 1 wherein the outer face sheet is comprised of a material that is more rigid than the material that comprises the inner face sheet.

12. A method according to claim 11 wherein the outer face sheet is comprised of a composite or metallic material and the inner face sheet is comprised of a composite material that is more flexible than the material that forms the outer face sheet.

13. A method according to claim 11 wherein the outer face sheet is comprised of a composite or metallic material and the inner face sheet is comprised of an elastomeric material.

14. A method according to claim 13 wherein the inner face sheet is comprised of rubber.

15. A method according to claim 1 wherein the outer face sheet is comprised of a composite or metallic material and the inner face sheet is comprised of material that is resistant to liquid.

16. A method according to claim 1 wherein the outer face sheet is comprised of a composite or metallic material and the inner face sheet is comprised of material that is resistant to fuel.

17. A method according to claim 1 further comprising positioning a pressure release valve so as to open through the inner wall.