Tuesday, June 5, 2018

Which Structural Analysis software is the most precise?

Perhaps for many of you already familiar with Structural Analysis software, this question makes no much sense whatsoever.
 
Nonetheless, and believe it or not, this a very common question among those fellow engineers how are not sure about moving into a computer aided solution for Analysis, Design and Calculation of Structures.
Of course, this question has an honest real concern behind it, since if you base your design in the analysis results of a faulty program, you could seriously be  putting lives at risk, or your career at the very least...
So, and for those who are really looking for an answer to this question, the answer is...all of them...

Or to be "precise", the one software being imprecise will be the big exception among all them.

You will have to be looking for a Structural Analysis software in the "wrong places" to find such a marvel of programming.

But let me clarify things for you, just in case this last argument isn't convincing enough.

Asking which Structural Analysis software is "the most precise"  is just like asking which calculator among any of your computers (if you own more than one) is the most precise...

Well obviously, and to begin with, any of them will be far more accurate when solving complex integrals in infinitesimal calculations than any human being. And far more reliable...

Furthermore, calculations for the Analysis of a Structure performed manually are based in approximation methods (plastic and elastic analysis methods). And it couldn't be otherwise...that's why we use computers in the first place...

  
Are you getting the picture yet?

So, how accurate a Structural Analysis software can be? Simple...as much as computer can...
But if that's so, then why do we find structures calculated through a computer which look actually less robust than those calculated in a more "traditional" way?

The answer is also simple...criteria and experience.

Most seasoned Structural Engineers have already a set of criteria based upon experience. One may even say they can "feel" what's right. But more often, they already know what works.

Of course this doesn't mean that when put into practice, the resultant design of the Structure is 100% efficient, in fact this may be "over-calculated". But it gets the job done and it does it well.

So when we pair of up the results from an Structural Analysis, one made by your favorite analysis software and another by traditional means, there's always discrepancies.

But not because of the program messing up, but because this tends to be way more accurate than any calculation done manually.

Specially, when NO CRITERIA from the structural engineer is applied on the side of the computer.

Or even worst, when there's no clear idea on how to apply the correct Design Code inside the software being use...that would be indeed a fatal flaw of which the program isn't guilty at all.

Of course, none of us should ever picture a structural design which doesn't comply with the required Design Code.

But the sad reality, is that some rookies have no clue of what that Design Code of the particular country or region in which the project is being built says or does exactly. And they expect the program to "Auto-magically" know what to do when analyzing the design.

And in the bottom of my heart, I know this is the real reason behind questioning the level of accuracy of the results produced by a given program...

What if the results of the program aren't accurate!!??

....Shouldn't you be able to tell just by performing the analysis of a simple Steel Frame?

Well, if you have no clue of how the Design Code should rule a particular Design, or if you aren't "in tune" with how the Analysis of a Structure is performed...you may be in trouble.

So my honest advice is not to worry so much about the level of accuracy provided by a particular Structural Analysis software, is always going to be far higher than of any human being, and begin worrying more about becoming more proficient in Structural Analysis in general...and yes sit down and read the Design Code that concerns you. And understand how this affects the overall design of your structure.

But just in case you aren't fully convinced, Autodek RSA displays inside its many calculation reports, all the correspondent formulas being used, and how each of the results are being applied throughout the analysis.

So you may even perform a manual verification if you must.

For more information about Autodesk Robot Structural Analysis Professional, visit www.virginiae-learning.com