Moments at the connections between a horizontal beam and the 3 vertical beams supporting it

[dccd]

Homework Statement

Say that I have a continuous beam [b]resting on top of column[/b] spanning across 3 column. The applied load is UDL on the beam, here's how the BMD look like. My question is whether the connection between the beam and column need to sustain the moment ? Which point need to sustain the moment ? All 3 locations ? Or the edge of the beam only ?

Relevant Equations

None

Say that I have a continouos beam resting on top of column spanning across 3 column. The applied load is UDL on the beam, here's how the BMD look like. My question is whether the connection between the beam and column need to sustain the moment ? Which point need to sustain the moment ? All 3 locations ? Or the edge of the beam only ?The connection between the column and the beam is the beam will be welded to the plate , and the plate will be welded to the column.

I think the connection at the beam edge need to design to sustain the moment, correct me if I am wrong. The connection on the intermediate point need not designed to take the moment because the moment will be taken by the continuous beam alone. Correct me if I am wrong.

 

[256bits]

Correct me if I am wrong.

No right or wrong answer, since it is application dependent, but standard practices are usually followed in the majority of construction ( rather than let's just beef it up - actually that can have detrimental effects in real world unless you go through calculations ).

Did you figure out the reactions at the column supports?
And the support connection necessary - pin, roller, fixed ( in your case since it is welded ), or simple ( frictionless ).
That can lead you to answer more confidentially:
Does the column - centre and/or ends need moment support?
( Besides gravitational, end and sideways, twisting ).

Anyways, I am not too often on homework, as my posts are a bit sporadic and suffer time lag.

Hopefully someone with beam knowledge will come by and more carefully address your concern.

 

[PhanthomJay]

From symmetry, under vertical loads only, the horizontal reactions at the outside column pinned supports must be equal and opposite. That leaves no shear in the middle column, and thus no moment.