Is 70mm node displacement too much?

[youpi]

I got this 8.5x8.5m 4 storey frame with roof deck with which beam and column sections are applied with cross sectional inertia reduction of 0.35 and 0.7 respectively. Staad node displacement summary shows 70mm displacement on the uppermost node for the roof beams at critical load combination for lateral loads (horizontal direction). Analysis doesn't show any warning and all other checks seems good like story drift and stuff.

 

[MotorCity]

Depends......can your structure and its finishes tolerate that much movement? What does your code say? Wind? Seismic?

 

[driftLimiter]

Analysis doesn't show any warning and all other checks seems good like story drift and stuff.

This spooks me pretty bad. You cant design a 4 story building with software alone. You need apply a considerable amount of judgement and apply relevant standards. the software output seems good is not sufficient for life safety.

Other than that, what MotorCity said.

 

[human909]

This spooks me pretty bad.

I agree.

It is scary. I'm scared on what graduates are coming out. Their abilities and their expectations of what they can do and what their tools (software) can do.

While this forum might attract an unusually high number of them, I don't believe it is a complete misrepresentation of the cohort of younger engineers. Likewise we get people from less developed nations posting here too but I do think the problem stretches across most localities.

Also I do wonder if there is a hollowing out of the profession. I over 30year old structural engineers but plenty of 60+ engineers. There seems to be significant attrition of young engineers in the structural profession.


US DATA

 

[phamENG]

human909 - what is that graph, exactly?

 

[human909]

Good question phamENG. The graph does leave a few questions even if given more context.

https://www.structuremag.org/?p=7042

I picked it because it was all I could find. But the % scale does seem off as it isn't the % of the population or of the age cohort. But I have assumed that the histogram showing significant attrition helped support my arguement.

But given the questionable nature of the way the information is presented, I'd accept that it is inconclusive.

 

[PEinc]

human909, did you just do with the graph what you accused some others of doing with computer programs?

http://www.PeirceEngineering.com

 

[JoshPlumSE]

I have to say that there has to be a better person to ask than this forum. Someone you're working with who is supervising you, who knows a lot about this project.

 

[ThomasH]

@youpi

I really can't relate to the numbers based on your description. But 8500/70 = L/121 which is significant and can possibly be visible. If it is a problem is for you to decide.

It seems to me that you look to the software for information like warnings. The software is a tool for an engineer to use.

/Thomas