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bones206 said:The important point is that we should all be cognizant of the true behavior of structures and the reasoning behind generally accepted design simplifications. Then we know where the guardrails are and when to abandon simplifications in certain siutations when they aren't appropriate or conservative.
Well said bones206. That is what I've been trying to hammer home since the start.bones206 said:The important point is that we should all be cognizant of the true behavior of structures and the reasoning behind generally accepted design simplifications. Then we know where the guardrails are and when to abandon simplifications in certain siutations when they aren't appropriate or conservative.
No. As repeatedly said by me and again said possibly more clearly by bon206. Nobody is implying that "we can't model pins .... because they are not true pins". Nobody has said that, and that is a misrepresentation of what I and others have said.driftlimiter said:If we buy into this too much we can't model pins anywhere simply because they are not true pins. We have to think about partial moment connections everywhere. Years of practice essentially amount to "ignoring reality".
phamENG said:In a word - yes. I can back out a moment in the column based on its rotation. Whether the actual moment transferred is 3k-ft or 300k-ft, I proportion the connection for that moment.
human909 said:Quote (driftLimiter)
This "not a pinned connection" absolutism is odd. I see connections like that taken as pinned all the time.
Why do you find the reality odd? And why do you think that just because "you see it all the time" make it true?
Which on it's own isn't a problem. However when that statement is in the context of an explicit question on how to release the moment in the connection then it IS a problem because it doesn't achieve the goal.driftLimiter said:It was simply stated by Dave to design the connection as if it was pinned.
dauwerda said:I have no problem with treating this as a pinned connection in a structural model, I wouldn't do it blindly however.
dauwerda said:I would know that the rotation of the joint is self limiting based on the stiffness of the beam and I would have done some kind of calc that I know the plate will yield before it becomes an issue of overstressing the bolts in tension.
human909 said:Which on it's own isn't a problem. However when that statement is in the context of an explicit question on how to release the moment in the connection then it IS a problem because it doesn't achieve the goal.
Thanks. And it has been my point all along. Though like you say, the thread has ballooned and context is lost. And I could have done a better job of explaining the point.driftLimiter said:This is a fair point.
-Switch it to W8, put the bolts within the flanges.driftLimiter said:if the OP needs to release the moment what recommendation can we offer him?
milkshakelake said:This must be the eng-tips world record for a pretty innocuous post starting a storm of controversy
I in no way was trying to say that you were doing it blindly - you are the last person that I would ever accuse of doing anything blindly. So, I'm sorry if my post came across that way.KootK said:I don't feel that I do it blindly. I see to it that my Ib/Lb is several multiples of Ic/Lc and leave it at that.
I agree with you here as well. However, engineering judgement must be based on something, if you have nothing else to go on, run a calculation to make yourself feel comfortable. I also specifically addressed it as the (potential) issue was brought up in the post I was replying to.KootK said:To each his own. I don't feel that even that level of effort is necessary. My minimums for pinned cap plate connections for anything resembling serious construction are a 5/8" cap plate and 5/8" diameter bolts. Lots, and lots, and lots of experience with that (mine and others) has produced to problems that I am aware of.
dold said:will be a moment induced in the column even if there is no moment transferred from the beam to the column
MSL said:This must be the eng-tips world record for a pretty innocuous post starting a storm of controversy with zero input from OP.