sigmented cover plate fatigue catagory at tension flange

[TLycan]

Dears,

I've a steel built-up I girders 60 meter span bridge in which the bottom flange (tension flange) consists of two plates (the main bottom flange 100cmx5cm and a cover plate 80cmx4cm). the bottom flange is compromised of two plate due to a shortage in the local market.

the fabricator will attach the cover plate as following:-

after assembling the built-up I, he will CJP weld the cover plate in 12meter segments on the bottom flange; thus the bottom flange will act as a backing plate.

My question is:- what is the fatigue category in bottom flange at location of the cover plate weld (refer to attached sketch)

thanks

 

[bridgebuster]

The end of the coverplate is Category E', based on thickness. That could be brought down to Category B by bolting the end of the coverplate.

The transverse weld in the coverplate to the basemetal could be Category D. This example is part of the AASHTO fatigue details for orthotropic decks, but could be applicable to your situation.

 

[TLycan]

Thanks

 

[bridgebuster]

You’re welcome