Plate compression stress vs. Euler's buckling stress.

[PSSC]

I tried to post this earlier, if it is a repeat, I apologize.

I watched a webinar presented by RISA a couple of months ago on modeling non-building structures.
The model centered around a tank comprised of plate elements.
The presenter found the vertical (compressive) forces, divided by the area, to find the compressive stress.
She then compared this to Euler's buckling stress.

Another person watching the webinar, commented that they thought this comparison was not the correct method.
The webinar ended almost immediately after this and I never heard/saw a response to this comment.

Would anyone here have a thought on whether this comparison is valid?

I had forgotten about this until today when I was working on a model that has plate elements in compression.

I will try to contact RISA today to see if they have an response.

Thanks,

 

[JoshPlumSE]

I just chatted with the person who gave that webinar. Her method was meant to be a quick and conservative method. Which it is. The person who made that comment (if our engineer remembers correctly) was merely pointing out that it was too conservative.

Once upon a time (in my previous life as a structural engineer with a company doing heavy industrial projects) I remember taking a "cross-training" class with the pressure vessel folks. I'm sure they had better formulas for the buckling stress of a circular tank. I don't have all my notes from that class, so I can't give them to you. But, I'm confident they exist.

Lastly, there should be a Q&A summary posted with that webinar somewhere that shows all the questions asked and the responses we gave. Even the ones that came up shortly after the webinar concluded. I'll try to attach that (or a link to that) in a follow up post.

 

[JoshPlumSE]

I believe the answer to this question was:
Q: We don’t think the buckling analysis is correct...
A: This is a conservative approach to overcome the fact that RISA does not perform a true nonlinear buckling analysis.

https://risa.com/documents/webinars/WebinarQ&A_Non-Building_Structures.pdf

Like I said in my previous post, I'm sure those who work with tanks (or vessels) regularly will have more accurate formulas to use.

 

[PSSC]

Thank you, this is what I had guessed was the case but wanted to clarify.