Knee Braced Moment Fame
Knee Braced Moment Fame
(OP)
I am evaluating 115' tall industrial structure. The structure is inverted V braced (concetricaly braced per AISC seismic provision)in one direction and knee braced in other direction. Sesismic zone is D.
My question is how to categorize Knee Braced frame per AISC seismic provision and detail the connections. Is it a
1. Special or Ordinary Moment Frame or
2. Ordinary Brace Frame (however, OBF are limited to 60' height in Zone D)
My question is how to categorize Knee Braced frame per AISC seismic provision and detail the connections. Is it a
1. Special or Ordinary Moment Frame or
2. Ordinary Brace Frame (however, OBF are limited to 60' height in Zone D)






RE: Knee Braced Moment Fame
RE: Knee Braced Moment Fame
The 'Link'is relatively long, I assume it will be flexture controlled, do you agree?
RE: Knee Braced Moment Fame
RE: Knee Braced Moment Fame
RE: Knee Braced Moment Fame
1) Where in the AISC manual or IBC does the knee-brace prohibition appear?
2) If the column is specially stiffened at the knee-brace joint to prevent a plastic hinge from forming there first, is that addressed in the Code?
RE: Knee Braced Moment Fame
RE: Knee Braced Moment Fame
Taro, your explanation makes sense.
RE: Knee Braced Moment Fame
but how close the diagonal of the knee brace is to the beam/column intersection would effect the behavior of the system.
When the knee brace is as far away from the joint as possible would it not behave similiar to a concentric braced frame (inverted v type) as the diagonal moves closer to the joint it behaves more as an eccentric braced frame. And when it is finally very close to the joint is it not just behaving as a moment frame.
Now i understand that the seismic requirments may not recognize this behavior in the higher seismic regions but in the wind controled regions were the seismic detailing provisions are not required, why not use an approximate r value based on the how how close it is behaving to a moment frame to check you seismic forces and proceed to design for wind.
even in regions were seismic controls but the detailing requirments are not required it may work.
i'm sure someone has a comment
thanks for listening
RE: Knee Braced Moment Fame
RE: Knee Braced Moment Fame