Stiffness of Partial Moment Connections

I typically try to avoid specifying full moment connections and instead list the factored moment that I require from a connection in an effort to decrease the steel costs.

However, I have a situation where my factored moment is only 10% of the moment capacity of the weaker member being connected. If the connection is designed for this factored moment, can I really expect the stiffness of the connection to behave as if it were connected for 100% of the moment capacity? If not, is a full moment connection required to assume that deflections can be based off of a fixed connection type?

For my current situation I have multiple small moment frames supporting glass spandrel glass therefore I am more concerned about deflection than moment capacity. I’ve decided to use full moment connections.


Maybe I’m missing something but I can’t see how if the moment demand at the connection is 10% of your member size. Using an 8"x1" plate vs a 8"x1/4" plate is going increase the frame stiffness much. Assuming the frame has much larger dimensions that 8" tall. I mean essentially your talking PL/AE PL is so short your talking 100’s of an inch right? I think it has more to do with how the connection is detailed i.e. end plate (more flexible) vs top / bot flange welded to the column (less flexible).

Above is a snippet.

I ended up modeling this and it actually does make more of a difference than I thought.