Alternate to Rivets

[DesEngineer4]

Hello All,

I have TWO aerostructure frames that needs to be Joined rigidly using any NAS approved fasteners or any other type of Hardware, after assembly that joint should feel and act like a Permanent Joint. I thought of using tensile lock bolts but not sure on the rigidity, yet to do the Joint analysis. Are there any other options that I can consider and available in Market for Aerospace application. Please share your thoughts and also, I have attached one snap with a sample frame. Thank you for your time!

Thanks & Regards

 

[IRstuff]

You've not given any information about materials or strengths, so any suggested solutions may not be appropriate for your application.
> rivets
> structural tapes, like VHB
> epoxy
> snap-together construction
> welding
> bolts


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[SWComposites]

Suggest using HiLoks.

 

[rb1957]

2nd that ... Hi-Loks or Hi-Lites surprisingly Ti Hi-Lites are often cheaper than good ol' Hi-Loks.

or steel MS bolts ... with nuts or anchor nuts.

Nowhere near enough info to give sensible options.

"Hoffen wir mal, dass alles gut geht !"
General Paulus, Nov 1942, outside Stalingrad after the launch of Operation Uranus.

 

[RoarkS]

Spotwelds

 

[SWComposites]

Maybe first answer: why do you not want to use rivets?

 

[dik]

Thanks... had not heard of them.

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-Dik

 

[rb1957]

I'm thinking the OP is thinking about tension loads.

"Hoffen wir mal, dass alles gut geht !"
General Paulus, Nov 1942, outside Stalingrad after the launch of Operation Uranus.

 

[TugboatEng]

In the world of shaft couplings it's common to use body bound bolts. The holes are reamed to a precise diameter and the bolt bodies are sized for a light interference fit. Smaller diameter bolts can be driven into the holes. Larger diameter requires some temperature differential. If your structure is aluminum and bolts steel you may want to consider some extra interference due to differences in CoTE.

 

[DesEngineer4]

Thank you all for your responses.

In previous batch we were using Rivets and welding but I'm exploring new method of Joints other than Rivet/Weld for upcoming batch. If we are not satisfied with new method, we may endup going with rivets/weld again. Before concluding, I wanted to make sure that I have tried all available options.

Based on the above responses, below are the two options. Did I miss anything else?

Tensile Lock Bolts
Hi - Loks

@Irstuff, could you please elaborate on Snap-together Construction?

Thank you once again for all your time!

Thanks & Regards

 

[SWComposites]

I would look at redesigning the frames to have a shear joint between them rather than a tension type joint.

 

[TugboatEng]

A rivet makes an interference fit. I don't believe Hi-Lok fasteners would be a direct replacement. Jo-Bolts swage themselves into the hole and may be a better alternative.

 

[rb1957]

Hi-Loks go in, AFAIK, with "some" interference ... more than an MS nut and bolt, I'd've thought more than a Jo-bolt. Maybe a rivnut sleeve ?

"Hoffen wir mal, dass alles gut geht !"
General Paulus, Nov 1942, outside Stalingrad after the launch of Operation Uranus.

 

[RoarkS]

Regarding HiLok... If someone would point me towards a hole size spec I'd appreciate it. I **thought** I had gone completely through a Boeing 737 SRM looking for what size to drill. Best I found was IAW with rivet hole sizes.

I'll 2nd the Jobolt.

Also 2nd the design the frame to shear if at all possible.

 

[Ng2020]

What is the motivation for changing the design in the first place?

 

[rb1957]

google "Hi-Lok installation instructions" ... it took you several guesses (couldn't find anything on Lisi site, they have a "maintenance" page, but it doesn't want to open).

it took me to a doc "

https://vdocuments.net/hi-lok-installation.html?page=1"

with hole preparation steps. Not obvious how to download the doc ...

"Hoffen wir mal, dass alles gut geht !"
General Paulus, Nov 1942, outside Stalingrad after the launch of Operation Uranus.

 

[WKTaylor]

Guys... normally I would chime-in on fastening ideas... BUT NOT this time.

NO clear definition of...

'WHY 2-frames... not one'????????
Loads
Materials
Pure frame... or frames with webs, ETC...

This is simply NOT how parts like these should be fastened together... unless of course they are thin sheet metal... which would make NO sense based on the OP's image.

Regards, Wil Taylor
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