design against lateral wind loading

[ejesper]

I am designing a 4-storey steel frame structure, just wondering whether is better to use diagraphm or shear wall to design against lateral wind loading.

 

[ERV]

Why not use a moment frame or braced frame?

 

[JAE]

ejesper - almost all buildings use the floor/roof diaphragm as part of the lateral resisting system.

Shear walls are vertical elements that receive lateral forces from diaphragms (floors/roof).

Not sure what exactly is your question. Are you asking about what type of lateral bracing to use?

 

[CSEllc]

I agree.....the floor and roof will be your diaphragms. Depending on the architectural layout, either a moment frame, concentric or eccentric braced frame would be the way to go.

If you choose to go with the eccentric brecaed frame, and assuming you follow all the requirements listed in the AISC Seismic spec, for the eccentric frame, it qualifies as a "special type" frame which reduces the seismic forces on the structure. Which, in turn will reduce the forces on the members, which will in turn reduce the forces to the foundations, etc......

 

[AlohaBob]

I think that in any case of vertical loadpath system, you need the diaphram at floor levels to distribute loads to the vertical lateral system.

A better question would seem to be, which lateral system is best, moment frame, braced frame, or shearwall system?

Since you are designing a steel frame, any option works. More information would be helpful though to decide.