I am designing an ordinary moment frame as defined by AISC 341-05. All beams and braces are pin connections. Please see the attached.
Frame A - just an example of a perfectly acceptable moment frame using knee braces.
Frame B - Is this allowed to be qualified as an ordinary moment frame? I would guess "no" because it precludes yielding by bending of the beams. But does the yielding mechanism of the have to be in beams, or can it be in columns for OMF as well? AISC 341 seems to allow it for OMF, but not SMF.
Frame C - Does this now become a special truss frame? or can I still consider this an ordinary moment frame?
Frame A - just an example of a perfectly acceptable moment frame using knee braces.
Frame B - Is this allowed to be qualified as an ordinary moment frame? I would guess "no" because it precludes yielding by bending of the beams. But does the yielding mechanism of the have to be in beams, or can it be in columns for OMF as well? AISC 341 seems to allow it for OMF, but not SMF.
Frame C - Does this now become a special truss frame? or can I still consider this an ordinary moment frame?
