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That wasn't your contention early. Your contention early relied on assuming away the moment.DaveAtkins said:I still contend that a tall, slender column will have a relative stiffness so small that the moment in the cantilever will mostly transfer to the much stiffer beam backspan, and not to the column.
We are talking about the connection here. If it was as you say then we could just call it a moment connection and design it as such.DaveAtkins said:The column will not attract much moment, and the connection can be treated as pinned. It has less to do with the thickness of the bearing plate and the fact that there are four bolts, and more to do with the relative stiffness between the beam and the column.
Not at all. If your model assumes a pinned connection then your column won't see any moment and thus no deflection. The beam deflection might be perfectly within acceptable limits. But if in reality it is a rigid connection your column will see any rotation that the beam has and deflect according.DaveAtkins said:And if you are seeing beams and columns deflecting too much, then that is a function of not checking deflection, not a function of assuming a connection is pinned or fixed.
I can dig up plenty of pin connections in buildings if you want. Maybe you are the sort of engineer that is willing to "willing to accept more uncertainty in the details" but I am not. If I want a pin I aim to provide a flexible connection, if I want a rigid connection I provide a rigid connection. If I'm unsure of the connection behaviour then I investigate it and also consider the implications of both outcomes on the structure.DaveAtkins said:Oh, and the photo of the railroad bridge connection? Bridge structures are much more susceptible to fatigue due to repeated load cycles, so bridge structures tend to have connections that are detailed as real pins. Building structures do not see these kinds of load cycles, so engineers are willing to accept more uncertainty in the details.
human909 said:But I think you are now just arguing to save face. Rather than engaging in reasonable engineering discussion so I'm done on this topic.