supported cone roof

[carthago]

case: Conical cone roof with supporting structure (rafters connected to in inner ring, no column). Due to corrosive product, vapor inside the tank above the liquid level, the rafter are located OUTSIDE the roof. Rafter are welded to the roof.

Question: how is the outer part of the rafter shall be fixed .
Is welding to the roof and then weldeing the roof onto the top angle is enough ?

Thanks for your tips, idea and suggestions

take care and thanks

 

[sajk14]

Sounds like a self supporting cone roof structure.

The external rafters would generally be welded onto roof plates shaped in a petal profile. The roof petal plate and rafter assembly would then be landed onto the top angle with an over lap of say 25mm and welded on the periphery of the roof plate to top angle connection with typically a 5mm fillet weld.

 

[carthago]

Sajk14

thank you for answer

question: are there special calculations to do ..on the shell to take into account the loads coming from the roof and the rafters under which the roof plates are welded?

If you can insert a typical sketch or drawing regarding this type of connection

thanks again

take care and thanks

 

[JStephen]

If the rafters extend right to the edge of the roof plate, I would think that would be adequate support for them. You could calculate the bending stresses in the roof plate to see how far back they could be placed.