I also studied FEM in undergrad and grad school. There's something very satisfying about breaking an intractably difficult real-world problem up into finite chunks of simplified, simulated reality and getting a useful, albeit explicitly imperfect, answer out of the other end. I find myself thinking about this approach often.
Eighty Years of the Finite Element Method (2022)
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Re: Eighty Years of the Finite Element Method (2022)
#12My hot take is that, FEM is best used as unit testing of Machine Design, not a guide towards design that it’s often used as. The greatest mechanical engineer I know, once designed an entire mechanical wrist arm with five fingers, actuations, lots of parts and flexible finger tendon. He never used FEM at any part of his design. He instead did it in the old fashioned, design and fab a simple prototype, get a feel for i…
> The greatest mechanical engineer I know, [...]
And with that you wrote the best reply to your own comment. Great programmers of the past wrote amazing systems just in assembly. But you needed to be a great programmer just to get anything done at all.
Nowadays dunces like me can write reasonable software in high level languages with plenty of libraries. That's progress.
Similar for mechanical engineering.
(Doing prototypes etc might still be a good idea, of course. My argument is mainly that what works for the best engineers doesn't necessarily work for the masses.)
Re: Eighty Years of the Finite Element Method (2022)
#13I started my career doing FE modeling and analysis with ANSYS and NASTRAN. Sometimes I miss these days. Thinking about how to simplify a real world problem so far that it is solvable with the computational means available was always fun. Then pushing quads around for hours until the mesh was good had an almost meditative effect. But I don't feel overwhelmingly eager to learn a new software or language. Much to my sur…
I've used ansys daily for over a decade, and the only movement is in how they name their license tiers. It's a slow muddy death march. Every year I'm fighting the software more and more, the sales men are clearly at the wheel.
They buy "vertical aligned" software, integrate it, then slowly let it die. They just announced they're killing off one of these next year, that they bought ten years ago, because they want to push a competitive product with 20% of the features.
I've been using nastran for half as long but it isn't much better. It's all sales.
I dabbed a bit in abaqus, that seems nice. Probably cause I just dabbed in it.
But here I'm just trying to do my work, and all these companies do is move capabilities around their license tiers and boil the frog as fast as they get away with.
Re: Eighty Years of the Finite Element Method (2022)
#14My hot take is that, FEM is best used as unit testing of Machine Design, not a guide towards design that it’s often used as. The greatest mechanical engineer I know, once designed an entire mechanical wrist arm with five fingers, actuations, lots of parts and flexible finger tendon. He never used FEM at any part of his design. He instead did it in the old fashioned, design and fab a simple prototype, get a feel for i…
> The greatest mechanical engineer I know, [...] And with that you wrote the best reply to your own comment. Great programmers of the past wrote amazing systems just in assembly. But you needed to be a great programmer just to get anything done at all. Nowadays dunces like me can write reasonable software in high level languages with plenty of libraries. That's progress. Similar for mechanical engineering. (Doing pro…
Also, might work for a mechanical arm the size of an arm, but not for the size of the Eiffel tower.
Re: Eighty Years of the Finite Element Method (2022)
#15I've been a full-time FEM Analyst for 15 years now. It's generally a nice article, though in my opinion paints a far rosier picture of the last couple decades than is warranted.
Actual, practical use of FEM has been stagnate for quite some time. There have been some nice stability improvements to the numerical algorithms that make highly nonlinear problems a little easier; solvers are more optimized; and hardware is of course dramatically more capable (flash storage has been a godsend).
Basically every advanced/"next generation" thing the article touts has fallen flat on its face when applied to real problems. They have some nice results on the world's simplest "laboratory" problem, but accuracy is abysmal on most real-world problems - e.g. it might give good results on a cylinder in simple tension, but fails horribly when adding bending.
There's still nothing better, but looking back I'm pretty surprised I'm still basically doing things the same way I was as an Engineer 1; and not for lack of trying. I've been on countless development projects that seem promising but just won't validate in the real world.
Industry focus has been far more on Verification and Validation (ASME V&V 10/20/40) which has done a lot to point out the various pitfalls and limitations. Academic research and the software vendors haven't been particularly keen to revisit the supposedly "solved" problems we're finding.
Re: Eighty Years of the Finite Element Method (2022)
#16I have such a fondness for FEA. ANSYS and COSMOS were the ones I used, and I’ve written toy modelers and solvers (one for my HP 48g) and even tinkered with using GPUs for getting answers faster (back in the early 2000s).
Unfortunately my experience is that FEA is a blunt instrument with narrow practical applications. Where it’s needed, it is absolutely fantastic. Where it’s used when it isn’t needed, it’s quite the albatross.
Re: Eighty Years of the Finite Element Method (2022)
#17I started my career doing FE modeling and analysis with ANSYS and NASTRAN. Sometimes I miss these days. Thinking about how to simplify a real world problem so far that it is solvable with the computational means available was always fun. Then pushing quads around for hours until the mesh was good had an almost meditative effect. But I don't feel overwhelmingly eager to learn a new software or language. Much to my sur…
COMSOL's big advantage is it ties together a lot of different physics regimes together and makes it very easy to couple different physics together. Want to do coupled structures/fluid? Or coupled electromagnetism/mechanical? Its probably the easiest one to use.
Each individual physics regime is not particularly good on its own - there are far better mechanical, CFD, electromagnetism, etc solvers out there - but they're all made by different vendors and don't play nicely with each other.
Re: Eighty Years of the Finite Element Method (2022)
#18My hot take is that, FEM is best used as unit testing of Machine Design, not a guide towards design that it’s often used as. The greatest mechanical engineer I know, once designed an entire mechanical wrist arm with five fingers, actuations, lots of parts and flexible finger tendon. He never used FEM at any part of his design. He instead did it in the old fashioned, design and fab a simple prototype, get a feel for i…
Would FEM be useful for that kind problem? It's more for figuring out if your structure will take the load, where stress concentrations are, what happens with thermal expansion. FEM won't do much for figuring out what the tolerance need to be on intricate mechanisms
Re: Eighty Years of the Finite Element Method (2022)
#19I started my career doing FE modeling and analysis with ANSYS and NASTRAN. Sometimes I miss these days. Thinking about how to simplify a real world problem so far that it is solvable with the computational means available was always fun. Then pushing quads around for hours until the mesh was good had an almost meditative effect. But I don't feel overwhelmingly eager to learn a new software or language. Much to my sur…
> Still no viable open-source solution. For the more low-level stuff there's the FEniCS project[1], for solving PDEs using fairly straight forward Python code like this[2]. When I say fairly straight forward, I mean it follows the math pretty closely, it's not exactly high-school level stuff. [1]: https://fenicsproject.org/ [2]: https://jsdokken.com/dolfinx-tutorial/chapter2/linearelastic...
Interesting. Please bear with me as this is going off 25 year old memories, but my memory is that the workflow for using FEA tools was: Model in some 3D modelling engineering tool (e.g. SolidWorks), ansys to run FEA, iterate if needed, prototype, iterate.
So to have anything useful, you need that entire pipeline? For hobbyists, I assume we need this stack. What are the popular modelling tools?
Re: Eighty Years of the Finite Element Method (2022)
#20My hot take is that, FEM is best used as unit testing of Machine Design, not a guide towards design that it’s often used as. The greatest mechanical engineer I know, once designed an entire mechanical wrist arm with five fingers, actuations, lots of parts and flexible finger tendon. He never used FEM at any part of his design. He instead did it in the old fashioned, design and fab a simple prototype, get a feel for i…
Garbage in garbage out. If you don't fully understand the model, then small parameter changes can create wildly different results. It's always good to go back to fundamentals and hand check a simplification to get a feel for how it should behave.