Contact US

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

electrical bonding of composite materials

electrical bonding of composite materials

electrical bonding of composite materials

What type of bonding is best for components that are fiberglass/epoxy and aluminum to meet the MIL-STD-464 5.11 at 10 milliohms thru 2.5 milliohms?

RE: electrical bonding of composite materials

Huh? fiberglass/epoxy is nonconductive, usually, so bonding in the EMI sense makes no sense.

FAQ731-376: Eng-Tips.com Forum Policies

Need help writing a question or understanding a reply? forum1529: Translation Assistance for Engineers

Of course I can. I can do anything. I can do absolutely anything. I'm an expert!
There is a homework forum hosted by engineering.com: http://www.engineering.com/AskForum/aff/32.aspx

RE: electrical bonding of composite materials

If an aluminum component is separated from other conductive components by an insulator like fiberglass /epoxy, then a bonding strap is used.

You are judged not by what you know, but by what you can do.

RE: electrical bonding of composite materials


Usually the problem with secondary structural composites [like fairings, tips, etc] is precipitation-static ['P-static'] charge build-up. This problem can be mitigated by anti-static coatings that also ground thru attachments fasteners and active static diverters such as trailing-edge static wicks. For components that cannot tolerate conductive coatings [such as antenna radomes, antenna covers, etc], and are subject to lightning strikes [primary lightning zone locations], then discretely placed metal straps [plain or segmented lightning diverter strips] bleed-off P-static and absorb/direct lightning pulses exterior surface of the composite, and lead directly to an aluminum airframe bond-point. These external straps are often sacrificial for aircraft safety [IE; absorb/redirect destructive lightning energy, one-time] and can be readily replaced.

For large area primary composite structure, methods are in-place to mitigate P-static build-up and to absorb/conduct-away lightning strikes. These ‘processes’ use conductive coating mechanisms [such as metallic/metalized coating; or conductive erosion coatings]; or wire-mesh or conductive filaments embedded into the entire outer composite layers, etc… using materials and methods which are highly proprietary. Electrical wire grounding paths [separate of conventional airframe ground/bonding paths] for aircraft systems components are mandatory. Extreme care [design, testing, fabrication, maintenance] is required for composite airframe structures, that also serve as integral fuel tanks, to eliminate all potential for static-arc, electrical-arc, lightning-arc/hot-spot ignition, etc, that could initiate fuel-fed fire/explosion.

Regards, Wil Taylor

o Trust - But Verify!
o We believe to be true what we prefer to be true.
o For those who believe, no proof is required; for those who cannot believe, no proof is possible.
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion"]
o Learn the rules like a pro, so you can break them like an artist. [Picasso]

RE: electrical bonding of composite materials

Electrical bonding in composite structures presents some challenges. But things are also not easy with metal airframes. Remember the horrible situation with electrical ground circuit faults causing an explosion in the center body fuel tanks of a 747?

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close