Monocoque marriage

[Ceboe]

Hi all,

we are building our first monocoque chassis and we are stuck at a particular question.
How do other teams combine the 2 halves of their monocoque?
We are working together with an aircraft manufacturer so they would like us to use rivets, like they are used to in their industry.
But I 've never seen a monocoque from other teams held together by rivets.
Do you guys just bond the two halves together?

[tgman]

TL : DR what are you making your monocoque from?

Plenty of teams have rivets on their monocoques. We technically run a semi monocoque with an ally composite front end and space frame rear, yes we have many many rivets in the front chassis but they are there to hold down glued brackets that join sheets together (so much easier than clamping everything while glue sets) and if we really wanted to save 20g they could be drilled out.

If you are using carbon or something along those lines just use more carbon and glue. The solar team I used to work with joined their two halves with a butt joint and then ran a strip of carbon around the inside and outside to create a double lap joint, no rivets. If you are confident in the dimensional accuracy of your molds just overlap the two halves and glue the joint.

I am sort of curious here, most aircraft manufacturers are either fabricated ally or carbon everything with no rivets (if you ever get a chance look at the wings on a DA-40, they are beautifully clean), are you building a metal monocoque with ribs and spars?

[Ceboe]

TL : DR what are you making your monocoque from?

Plenty of teams have rivets on their monocoques. We technically run a semi monocoque with an ally composite front end and space frame rear, yes we have many many rivets in the front chassis but they are there to hold down glued brackets that join sheets together (so much easier than clamping everything while glue sets) and if we really wanted to save 20g they could be drilled out.

If you are using carbon or something along those lines just use more carbon and glue. The solar team I used to work with joined their two halves with a butt joint and then ran a strip of carbon around the inside and outside to create a double lap joint, no rivets. If you are confident in the dimensional accuracy of your molds just overlap the two halves and glue the joint.

I am sort of curious here, most aircraft manufacturers are either fabricated ally or carbon everything with no rivets (if you ever get a chance look at the wings on a DA-40, they are beautifully clean), are you building a metal monocoque with ribs and spars?

We are building a fully carbon monocoque with a foamcore. We have a top part and a bottom port. We were thinking about bonding top and bottom together with some extra layers of carbon strips, were both parts meet.
So indeed making a butt joint and than on both outsides some strips of carbon. Indeed creating a double lap joint.
We were wondering if other teams also do it this way.

[rjwoods77]

Sorry I couldn't resist...

http://www.thedatereport.com/dating/wp-content/uploads/2013/12/mawwiage.gif

[Thrainer]

If you have a login at the FSG website, look at the ETH Zurich slides of EuroMold Frankfurt 2008, they describe the manufacturing of a wet-laminated monocoque with joined top and bottom part.

An even better solution is to cure the monocoque in one piece. This is slightly more difficult because of restricted accessibility, but still possible.

Regards
Thomas

[Ceboe]

If you have a login at the FSG website, look at the ETH Zurich slides of EuroMold Frankfurt 2008, they describe the manufacturing of a wet-laminated monocoque with joined top and bottom part.

An even better solution is to cure the monocoque in one piece. This is slightly more difficult because of restricted accessibility, but still possible.

Regards
Thomas

Thanks, this helps a lot !