# FEA: What's the point?

1. Apr 29, 2013

### cmmcnamara

Hey all,

I have a question that has been bothering my quite a bit lately. Please excuse my relative ignorance of the topic too while I babble

I am an BSME senior at Cal Poly with one year to go. Part of our curriculum is FEA done with FEMAP and I have yet to take the course (next year I will). However currently I am taking a technical elective which doesn't require us to have taken the course but nevertheless incorporates elements from every engineering course offered and meshes it into one giant machine design project. So essentially everyday is a bit of review/crash course on some engineering topic and then project work.

My professor was giving us the review/crash course on FEA and how it works behind the scenes. What I took away from the lesson is that FEA results are generally crap. That in general FEA underestimates the stress quite a bit and getting the best approximations you can takes years of experience to identify and interpret the results. Essentially, and I'm paraphrasing, "FEA results are meaningless without verification of the results with hand-calculations coupled with a grid-independence study." And I'm not one to doubt my professors, especially this one being the certified bad dude he is.

Which brings me to my question: What's the point of FEA?

I realize that computer results allow us to move through things quicker (or sometimes not--it sounds like FEA solutions can take days or weeks to calculate if large enough), but it seems to me just to be an added step to create a silly visual display for the customers/managers since the results are not what the actual designing criteria gets based off of. Is it really just visual way for us to get a point across at a single glance? Or are the results really actually useful? Is my professor's outlook unique on this topic?

I'd really appreciate any others input on understanding this topic and insight. And before you ask--no I haven't addressed the issue with my professor just yet, it's been a busy quarter!

Last edited by a moderator: May 3, 2013
2. Apr 29, 2013

### AlephZero

Hm... I've been using FEA in industry for several decades, and I've written some FE analysis programs to handle problems that were beyond the capability of any commercial software at the time I wrote them.

IMO either your prof doesn't know what he's talking about, or you got the wrong message.

The right message (and it's an important one!!!) is' "FEA results are meaningless unless the analyst knows what he/she is doing, and is using FEA software that has been properly designed and properly tested".

I don't have any experience of FEMAP, but I do know that MSC/NASTRAN, one of the industry standard FE vendors, has about 1200 employees world wide, including about 300 PhD-level engineers working on software development and new analysis methods. And their annual sales revenue is of the order of $200m to$300m.