Enhancing Z-Conductivity in Carbon Fiber Reinforced Plastic Composite Layups

Patent metadata

Field	Value
Publication number	US-2016347918-A1
Application number	US-201514721880-A
Country	US
Kind code	A1
Filing date	May 26, 2015
Priority date	May 26, 2015
Publication date	Dec 1, 2016
Grant date	—

Abstract

Carbon fiber reinforced plastic (“CFRP”) composite layups and processes for manufacturing CFRP composite layups that integrate z-conductivity features directly into CFRP composite layups during the manufacturing processes for lightning protection, more particularly, inherent edge glow protection from lightning direct effects, and electrical current flow path control. CFRP composite layups are configured during the manufacturing processes to provide inter-ply electrical connections between composite plies of the CFRP composite layups, therefore avoiding the need for add-on protection features that result in significant cost and weight penalties.

First claim

1 . A CFRP composite layup comprising a plurality of composite plies, each of the composite plies comprising a conductive carbon fiber reinforcement material, at least a portion of the conductive carbon fiber reinforcement material in each of the composite plies being electrically connected to at least a portion of the conductive carbon fiber reinforcement material in an adjacent ply of the CFRP composite layup to form inter-ply electrical connections.

2 . The CFRP composite layup of claim 1 , wherein the inter-ply electrical connections are made throughout an entire thickness of the CFRP composite layup, such that the carbon fiber reinforcement material in a bottom ply at a lower surface of the CFRP composite layup is electrically connected to the carbon fiber reinforcement material in a top ply at an upper surface of the CFRP composite layup.

3 . The CFRP composite layup of claim 1 , wherein the CFRP composite layup comprises a cut edge where ends of the conductive carbon fiber reinforcement material are exposed, and the inter-ply electrical connections are formed at or near the cut edge of the CFRP composite layup.

4 . The CFRP composite layup of claim 1 , wherein the plurality of composite plies comprises an upper ply at an upper surface of the CFRP composite layup, a lower ply at a lower surface of the CFRP composite layup, and one or more inner plies between the lower ply and the upper ply, one or more of the inner plies configured with an out-of-plane distortion at or near a cut edge of the composite plies where ends of the conductive carbon fiber reinforcement material are exposed, the out-of-plane distortion in the one or more inner plies forming the inter-ply electrical connections.

5 . The CFRP composite layup of claim 4 , further comprising one or more layered forming tools consisting of cured carbon fiber composite layups of specific dimensions smaller than dimensions of the CFRP composite layup embedded between at least two of the composite plies, the out-of-plane distortion in the one or more inner plies formed at an edge of the forming tools.

6 . The CFRP composite layup of claim 5 , wherein a first of the one or more layered forming tools is embedded between the upper ply of the CFRP composite layup and a first ply of the inner plies at a first position along a length of the CFRP composite layup to form a first out-of-plane distortion, and a second of the one or more layered forming tools is embedded between a second ply and a third ply of the inner plies at a second position along the length of the CFRP composite layup to form a second out-of-plane distortion staggered in a lengthwise direction from the first out-of-plane distortion.

7 . The CFRP composite layup of claim 1 , wherein the plurality of composite plies comprises an upper ply at an upper surface of the CFRP composite layup, a lower ply at a lower surface of the CFRP composite layup, and one or more inner plies between the lower ply and the upper ply, the upper ply having a length that is longer than the length of the lower ply and the one or more inner plies, and configured to wrap over a cut edge of the lower ply and the one or more inner plies where ends of the conductive carbon fiber reinforcement material are exposed, such that the carbon fiber reinforcement material in the upper ply makes electrical contact with the carbon fiber reinforcement material at the cut edge of each of the lower ply and the one or more inner plies.

8 . The CFRP composite layup of claim 7 , further comprising an electrically conductive sealant/adhesive between the upper ply and the cut edge of the each of the lower ply and the one or more inner plies.

9 . The CFRP composite layup of claim 3 , wherein a crimp is formed at or near the cut edge to push the conductive carbon fiber reinforcement material in each of the composite plies together and form the inter-ply electrical connections.

10 . The CFRP composite layup of claim 9 , wherein the crimp extends an entire length of the cut edge and substantially parallel to the cut edge.

11 . The CFRP composite layup of claim 9 , wherein the conductive carbon fiber reinforcement material in each of the composite plies are pushed together to within a distance of 10 micron or less.

12 . The CFRP composite layup of claim 3 , further comprising an electrically conductive material penetrating through an entire thickness of the CFRP composite layup in one or more rows to form the inter-ply electrical connections.

13 . The CFRP composite layup of claim 12 , wherein the conductive material has a conductivity of at least 10 4 Siemens/meter.

14 . A method of preventing edge glow in a CFRP composite layup comprising a plurality of composite plies, each of the composite plies comprising a conductive carbon fiber reinforcement material, the method comprising the steps of:
forming the CFRP composite layup such that at least a portion of the conductive carbon fiber reinforcement material in each of the composite plies is electrically connected to at least a portion of the conductive carbon fiber reinforcement material in an adjacent composite ply to form inter-ply electrical connections that reduce voltage potential between the composite plies during a lightning strike to the CFRP composite layup.

15 . The method of claim 14 , wherein the inter-ply electrical connections are formed at or near a cut edge of the CFRP composite layup where ends of the conductive carbon fiber reinforcement material are exposed and throughout an entire thickness of the CFRP composite layup, such that the carbon fiber reinforcement material in a bottom ply at a lower surface of the CFRP composite layup is electrically connected to the carbon fiber reinforcement material in a top ply at an upper surface of the CFRP composite layup.

16 . The method of claim 15 , wherein the plurality of composite plies comprises an upper ply at an upper surface of the CFRP composite layup, a lower ply at a lower surface of the CFRP composite layup, and one or more inner plies between the lower ply and the upper ply, the method further comprising the step of forming an out-of-plane distortion in one or more of the inner plies at or near the cut edge to form the inter-ply electrical connections.

17 . The method of claim 15 , further comprising embedding one or more layered forming tools consisting of cured carbon fiber composite layups of specific dimensions smaller than dimensions of the CFRP composite layup between at least two of the composite plies to form the out-of-plane distortion.

18 . The method of claim 15 , further comprising the steps of:
laying up a lower ply of the CFRP composite layup; laying up one or more inner plies of the CFRP composite layup onto the lower ply; laying up an upper ply of the CFRP composite layup onto the one or more inner layers, the upper ply having a length that is longer than the length of the lower ply and the one or more inner plies; wrapping the upper ply over the cut edge of each of the lower ply and the one or more inner plies, such that the carbon fiber reinforcement material in the upper ply makes electrical contact with the carbon fiber reinforcement material at the cut edge of each of the lower ply and the one or more inner plies.

19 . The method of claim 18 , further comprising the step of applying an electrically conductive sealant/adhesive between the upper ply and the cut edge of the each of the lower ply and the one or more inner plies.

20 . The method of claim 15 , further comprising forming a crimp at or near the

Assignees

• Boeing Co

Inventors

• Le Quynhgiao
• Greegor Robert B
• Whiting Brent Arthur

Classifications

• B32B3/18 Primary

  characterised by an internal layer formed of separate pieces of material {which are juxtaposed side-by-side (B32B5/02 takes precedence)} · CPC title

• B29C70/025

  with particular filler · CPC title

• B32B2260/046

  Synthetic resin · CPC title

• B32B2260/021

  Fibrous or filamentary layer · CPC title

• C08J2300/12

  Polymers characterised by physical features, e.g. anisotropy, viscosity or electrical conductivity · CPC title