ASD or LRFD for Connection Design Reactions

[McQSE]

Do you use ASD or LRFD when specifying the connection reactions on structural plans to be used by the fabricator for connection design? I realize that they should be able to design by both methods. I have designed the structure using LRFD. Is it acceptable to mix design procedures (LRFD for member sizing – ASD for connection design)?

 

[cap4000]

I would NOT mix up the methods. Essentially the two methods typically yield about the same connection designs and braced beam selections. What is your Live to Dead load ratio?? The 13ed AISC ASD/LRFD Manual uses an L/D=3 which corresponds to LRFD/1.50 = ASD value.

 

[swearingen]

Give them the service loads and let them do the factoring. Then they're free to use whichever method they want.



If you "heard" it on the internet, it's guilty until proven innocent. - DCS

 

[MightyPirate]

I agree with swearingen, service loads are the best way to go.

 

[nutte]

I disagree 100% with swearingen. Are you going to give them reactions for every load case (dead, live, wind in one direction, wind in the other direction, component and cladding wind, same for seismic, etc) and expect them to figure out which load combination produces the worst result? Good luck in getting the "right" answer.

The AISC Code of Standard Practice says the engineer of record is to provide data pertaining to loads (which I suppose would make swearingen's proposal "acceptable") and which methodology (ASD or LRFD) to use. If you've designed the building with LRFD, I can't think of any reason not to use LRFD for the connection design forces.

To answer the original questions:
We use whichever one we used to design the building.
and
It could very well be acceptable, but I would think it best to use the same method for both.