The discussion focuses on the types of joints in portal frames, specifically the connections between beams and columns, and columns to foundations. Participants explore the implications of these connections on the stability and behavior of the frame in two-dimensional and three-dimensional contexts.
Participants generally agree on the fixed nature of the beam to column connection in portal frames, but the discussion introduces a new question that remains unresolved regarding the flexibility of joints in different frame types.
The discussion does not fully explore the implications of joint flexibility on bending moments, leaving assumptions and definitions regarding joint behavior and frame stability unaddressed.
So, for portal frame, the beam to column connection must be fixed , am i right ?PhanthomJay said:Yes , correct on both counts. The beam to column connection is fixed, whereas the column base support can be fixed or pinned. If pinned at the base, the frame is stable in 2D, but in 3D, the Frame must be longitudinally braced or guyed.
There are other frames where the beam is pinned to the column, but these frames must be fixed at the base where each column shares half of the transverse load, but these frames are not called ‘portal’ frames and are weaker and subject to large deflections unless they are cross braced.
hellophysics said:this is probably elementary: Is it possible to decide the flexibility of a joint between gluelam beam and reinforced concrete column? if I decide it to be flexible, can it still the corner frame take bending moments? or then it behaves as a simply supported beam?
Lnewqban said:I recommend you to open a new one in order to get attention from a greater number of members, who can discuss details with you.
Perhaps, @berkeman can help with openining a new thread.