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Analytical or not?[Subject Prev][Subject Next][Thread Prev][Thread Next]
- To: "Sseaint Org" <seaint(--nospam--at)seaint.org>
- Subject: Analytical or not?
- From: "gregory szuladzinski" <ggg(--nospam--at)bigpond.net.au>
- Date: Wed, 5 Oct 2011 19:40:27 +1100
It all sounds like a storm in a teacup.
I think the underlying issue is whether someone is using closed formulas or numerical models.
The term "analytical" has often be used for both and the usage will so remain.
If you are discussing matters within more specialized, computational domain,
you are likely to make a distinction between analytical (closed form) and numerical (formless).
The first of those uses a calculator or, these days, Mathcad and the likes of it.
The second is mainly FEA, sometimes discrete elements, occasionaly boundary elements.
A spreadsheet, on the other hand, can support both.
You did not say you wanted to hear an opinion from Australia,
but I thought I might volunteer my two cents worth.
Gregory form Oz
From: Alexander Bausk <bauskas(--nospam--at)gmail.com>
Subject: Re: "Analytical model"
Content-Type: text/plain; charset=windows-1252
"right" is "richtig"; "rechen" is derived from rechnen, "(to) count".
I'm not sure about the German terms. It is essentially a bait to lure Germa=
listers to the thread (there are some AFAIK).
What I'm sure about is, we say something like "structural model", or
"calculation model" to describe any generic formalized model of a structure=
Then, all sort of generic calculation models are, mathematically speaking,
split into two domains: analytical and computational. You may clearly see
this is a common scheme throughout many engineering and research discipline=
by reviewing this search: http://goo.gl/FvHKt.
Analytical model has a closed form solution, that is, it can be solved in
one iteration using the simplest operators. If your model is Y=3Df(X), you =
usually able to retrieve the inverse solution, X=3Df'(Y), and express it in
more or less simple terms.
In practice, any code check is deemed analytical and the common term used t=
humiliate junior engineers, the "hand analysis", usually redirects here (if
you are not solving FE matrices by hand which is quite possible).
Computational model is usually highly iterative and includes complex
procedures like FEA, boundary element analysis or CFD. It is still called
analysis of course (in your language). You cannot directly express X
depending on Y in this case.
In other terms, your 15-minute-to-design ACI Excel spreadsheet calc is most
likely analytical while any FE model is computational. These two models may
actually describe the same structure like a pinned beam.
Any FEA software verification manual will host dozens of comparisons of
computational vs. analytical models describing the same structures.
So yes, I think this is actually the most fundamental difference there is.
And the current term usage disturbs me, especially when I see it propagatin=
to masses on Autodesk venues and help materials (and they are darn good at
P.s. I'm sorry if I was getting too much narrative, that is just to be
completely clear on the subject, I am clearly not qualified to lecture
anybody on the list.
- Re: Analytical or not?
- From: Alexander Bausk
- Re: Analytical or not?
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