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I 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 f

I 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 surprise, it seems there hasn't been much movement there. ANSYS still seems to be the leader for general simulation and multi-physics. NASTRAN still popular. Still no viable open-source solution. The only new player seems to be COMSOL. Has anyone experience with it? Would it be worth a try for someone who knows ANSYS and NASTRAN well?

kayo_20211030 2y ago
As a recovering fe modeler, I understand completely.
magicalhippo 2y ago
> 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/ https://fenicsproject.org/ [2]: https://jsdokken.com/dolfinx-tutorial/chapter2/linearelasticity_code.html https://jsdokken.com/dolfinx-tutorial/chapter2/linearelastic...
- lll-o-lll 2y ago
  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?
  - magicalhippo 2y ago
    Yeah not my domain so wouldn't really know. For FEniCS I know Gmsh[1] was used. There's some work[2][3] been done to integrate FEniCS with FreeCAD. It seems FreeCAD also supports[4] other FEM solvers. But, I guess you get what you pay for in this space still. [1]: https://gmsh.info/ https://gmsh.info/ [2]: https://github.com/qingfengxia/Cfd https://github.com/qingfengxia/Cfd [3]: https://github.com/qingfengxia/FenicsSolver https://github.com/qingfengxia/FenicsSolver [3]: https://wiki.freecad.org/FEM_Solver https://wiki.freecad.org/FEM_Solver
    - physicsguy 2y ago
      You can export other CAD meshes for use in it
  - fn-mote 2y ago
    > For hobbyists, I assume we need this stack. Just curious what kind of hobby leads to a finite element analysis?
    - kragen 2y ago
      Electronics (when you start to care about EMI or antenna design), model airplanes (for aerodynamics), rocketry, machining (especially if you want to get into SPIF), robotics, 3-D printing (especially for topology optimization), basically anything that deals with designing solid structures in the physical world. Also, computer graphics, including video games. Unfortunately the barrier to entry is too high for most hobbyists in these fields to use FEM right now.
      - nativeit 2y ago
        There are some obvious downsides and exceptions to this sentiment, but on balance, I really appreciate how the expansive access to information via the internet has fostered this phenomenon: where an unremarkable fella with a dusty media studies degree, a well-equipped garage, and probably too much free time can engineer and construct robotic machines, implement/tweak machine vision mechanisms, microwave radio transceivers, nanometer-scale measurements using laser diodes and optical interferometry, deep-sky astrophotography, etc., etc.. Of course, with burgeoning curiosity and expanding access to surplus university science lab equipment, comes armchair experts and the potential for insufferability[0]. It’s crucial to maintain perspective and be mindful of just how little any one person (especially a person with a media studies degree) can possibly know. [0] I’m pretty sure “insufferability” isn’t a real word. [Edit: don’t use an asterisk for footnotes.]
hhoorzad 2y ago
Abaqus is pretty big too. I've worked with both Ansys and Abaqus and I generally prefer the latter.
navane 2y ago
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.
- angry_moose 2y ago
  I've gone Abaqus > Ansys > Abaqus/LS-DYNA over my career and hate Ansys with a fiery passion. It's the easiest one to run your first model in, but when you start applying it to real problems its a fully adversarial relationship. The fact you have to make a complete copy of the geometry/mesh to a new Workbench "block" to run a slightly different load case (and you can't read in an orphaned results files) is just horrible. Abaqus is more difficult to get up to speed in, but its really nice from an advanced usability standpoint. They struggle due to cost though, it is hugely expensive and we've had to fight hard to keep it time and time again. LS-Dyna is similar to Abaqus (though I'm not fully up in it yet), but we're all just waiting to see how Ansys ruins it, especially now that they got bought out by Synopsys.
  - navane 2y ago
    I don't know how long ago you used ansys, and i definitely don't want to sell it, but you can share geometry/mesh between those "blocks" (by dragging blocks on top of each other), and you can read in result orphaned result files.
angry_moose 2y ago
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.
littlestymaar 2y ago
> The only new player seems to be COMSOL Ouch. I kind of know Comsol because it was already taught in my engineering school 15 years ago, so that it still counts as a “new entrant” really gives an idea of how slow the field evolves.
- petters 2y ago
  The COMSOL company was started in 1986....
  - arnejenssen 2y ago
    It used to be called FEMLAB :) But they changed to COMSOL because they didn't have the trademark in Japan and FEM also gave associations to the feminine gender.
master_crab 2y ago
Still no viable open-source solution. Wait? What? NASTRAN was originally developed by NASA and open sourced over two decades ago. Is this commercial software built on top that is closed source? I’m astonished ANSYS and NASTRAN are still the only players in town. I remember using NASTRAN 20 years ago for FE of structures while doing aero engineering. And even then NASTRAN was almost 40 years old and ancient.
- formerly_proven 2y ago
  There's a bunch of open source fem solvers e.g. Calculix, Code_Aster, OpenRadioss and probably a few unmaintained forks of (NASA) NASTRAN, but there's no multiphysics package I don't think.
  - bobim 2y ago
    These are at least capable of thermomechanical with fluid-structure coupling. Not all-physics but still multi. True that things with multi species diffusion or electromagnetics are missing, but maybe Elmer can fill the gap.
MengerSponge 2y ago
Once you have a mesh that's "good enough", you can use any number of numeric solvers. COMSOL has a very good mesher, and a competent geometry editor. It's scriptable, and their solvers are also very good. There might be better programs for some problems, but COMSOL is quite nice.
foxglacier 2y ago
I work in this field and it really is stagnant and dominated by high-priced Ansys/etc. For some reason silicon valley's open sourceness hasn't touched it. For open source, there's CalculiX which is full of bugs and Code Aster which everybody I've heard about it from say it's too confusing to use. CalculiX has Prepomax as a fairly new and popular pre/post.
drpossum 2y ago
I've worked with COMSOL (I have a smaller amount of ANSYS experience to compare to). For the most part I preferred COMSOL's UI and workflow and leveraged a lot of COMSOL's scripting capabilities which was handy for a big but procedural geometry I had (I don't know ANSYS's capabilities for that). They of course largely do the same stuff. If you have easy access to COMSOL to try it out I'd recommend it just for the experience. I've found sometimes working with other tools make me recognize some capabilities or technique that hadn't clicked for me yet.
karencarits 2y ago
OpenFOAM seems like an opensource option but I have found it rather impenetrable - there are some youtube videos and pdf tutorials, but they are quite dense and specific and doens't seem to cover the entire pipeline Happy to hear if people have good resources!
goodtruck 2y ago
I am hoping this open source FEM library will catch on : https://www.dealii.org/ https://www.dealii.org/. The deal in deal.II stands for Differential Equation Analysis Library. It's written in C++, makes heavy use of templates and been in development since 2000. It's not meant for solid mechanics or fluid mechanics specifically, but for FEM solutions of general PDEs. The documentation is vast, the examples are numerous and the library interfaces with other libraries like Petsc, Trilinos etc. You can output results to a variety of formats. I believe support for triangle and tetrahedral elements has been added only recently. In spite of this, one quirk of the library is that meshes are called "triangulations".
class3shock 2y ago
Abaqus is up there with Ansys aswell as others have mentioned.

kayo_20211030 2y ago

As a recovering fe modeler, I understand completely.

magicalhippo 2y ago

> 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/ https://fenicsproject.org/ [2]: https://jsdokken.com/dolfinx-tutorial/chapter2/linearelasticity_code.html https://jsdokken.com/dolfinx-tutorial/chapter2/linearelastic...

lll-o-lll 2y ago
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?
- magicalhippo 2y ago
  Yeah not my domain so wouldn't really know. For FEniCS I know Gmsh[1] was used. There's some work[2][3] been done to integrate FEniCS with FreeCAD. It seems FreeCAD also supports[4] other FEM solvers. But, I guess you get what you pay for in this space still. [1]: https://gmsh.info/ https://gmsh.info/ [2]: https://github.com/qingfengxia/Cfd https://github.com/qingfengxia/Cfd [3]: https://github.com/qingfengxia/FenicsSolver https://github.com/qingfengxia/FenicsSolver [3]: https://wiki.freecad.org/FEM_Solver https://wiki.freecad.org/FEM_Solver
  - physicsguy 2y ago
    You can export other CAD meshes for use in it
- fn-mote 2y ago
  > For hobbyists, I assume we need this stack. Just curious what kind of hobby leads to a finite element analysis?
  - kragen 2y ago
    Electronics (when you start to care about EMI or antenna design), model airplanes (for aerodynamics), rocketry, machining (especially if you want to get into SPIF), robotics, 3-D printing (especially for topology optimization), basically anything that deals with designing solid structures in the physical world. Also, computer graphics, including video games. Unfortunately the barrier to entry is too high for most hobbyists in these fields to use FEM right now.
    - nativeit 2y ago
      There are some obvious downsides and exceptions to this sentiment, but on balance, I really appreciate how the expansive access to information via the internet has fostered this phenomenon: where an unremarkable fella with a dusty media studies degree, a well-equipped garage, and probably too much free time can engineer and construct robotic machines, implement/tweak machine vision mechanisms, microwave radio transceivers, nanometer-scale measurements using laser diodes and optical interferometry, deep-sky astrophotography, etc., etc.. Of course, with burgeoning curiosity and expanding access to surplus university science lab equipment, comes armchair experts and the potential for insufferability[0]. It’s crucial to maintain perspective and be mindful of just how little any one person (especially a person with a media studies degree) can possibly know. [0] I’m pretty sure “insufferability” isn’t a real word. [Edit: don’t use an asterisk for footnotes.]

hhoorzad 2y ago

Abaqus is pretty big too. I've worked with both Ansys and Abaqus and I generally prefer the latter.

navane 2y ago

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.

angry_moose 2y ago
I've gone Abaqus > Ansys > Abaqus/LS-DYNA over my career and hate Ansys with a fiery passion. It's the easiest one to run your first model in, but when you start applying it to real problems its a fully adversarial relationship. The fact you have to make a complete copy of the geometry/mesh to a new Workbench "block" to run a slightly different load case (and you can't read in an orphaned results files) is just horrible. Abaqus is more difficult to get up to speed in, but its really nice from an advanced usability standpoint. They struggle due to cost though, it is hugely expensive and we've had to fight hard to keep it time and time again. LS-Dyna is similar to Abaqus (though I'm not fully up in it yet), but we're all just waiting to see how Ansys ruins it, especially now that they got bought out by Synopsys.
- navane 2y ago
  I don't know how long ago you used ansys, and i definitely don't want to sell it, but you can share geometry/mesh between those "blocks" (by dragging blocks on top of each other), and you can read in result orphaned result files.

angry_moose 2y ago

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.

littlestymaar 2y ago

> The only new player seems to be COMSOL Ouch. I kind of know Comsol because it was already taught in my engineering school 15 years ago, so that it still counts as a “new entrant” really gives an idea of how slow the field evolves.

petters 2y ago
The COMSOL company was started in 1986....
- arnejenssen 2y ago
  It used to be called FEMLAB :) But they changed to COMSOL because they didn't have the trademark in Japan and FEM also gave associations to the feminine gender.

master_crab 2y ago

Still no viable open-source solution. Wait? What? NASTRAN was originally developed by NASA and open sourced over two decades ago. Is this commercial software built on top that is closed source? I’m astonished ANSYS and NASTRAN are still the only players in town. I remember using NASTRAN 20 years ago for FE of structures while doing aero engineering. And even then NASTRAN was almost 40 years old and ancient.

formerly_proven 2y ago
There's a bunch of open source fem solvers e.g. Calculix, Code_Aster, OpenRadioss and probably a few unmaintained forks of (NASA) NASTRAN, but there's no multiphysics package I don't think.
- bobim 2y ago
  These are at least capable of thermomechanical with fluid-structure coupling. Not all-physics but still multi. True that things with multi species diffusion or electromagnetics are missing, but maybe Elmer can fill the gap.

MengerSponge 2y ago

Once you have a mesh that's "good enough", you can use any number of numeric solvers. COMSOL has a very good mesher, and a competent geometry editor. It's scriptable, and their solvers are also very good. There might be better programs for some problems, but COMSOL is quite nice.

foxglacier 2y ago

I work in this field and it really is stagnant and dominated by high-priced Ansys/etc. For some reason silicon valley's open sourceness hasn't touched it. For open source, there's CalculiX which is full of bugs and Code Aster which everybody I've heard about it from say it's too confusing to use. CalculiX has Prepomax as a fairly new and popular pre/post.

drpossum 2y ago

I've worked with COMSOL (I have a smaller amount of ANSYS experience to compare to). For the most part I preferred COMSOL's UI and workflow and leveraged a lot of COMSOL's scripting capabilities which was handy for a big but procedural geometry I had (I don't know ANSYS's capabilities for that). They of course largely do the same stuff. If you have easy access to COMSOL to try it out I'd recommend it just for the experience. I've found sometimes working with other tools make me recognize some capabilities or technique that hadn't clicked for me yet.

karencarits 2y ago

OpenFOAM seems like an opensource option but I have found it rather impenetrable - there are some youtube videos and pdf tutorials, but they are quite dense and specific and doens't seem to cover the entire pipeline Happy to hear if people have good resources!

goodtruck 2y ago

I am hoping this open source FEM library will catch on : https://www.dealii.org/ https://www.dealii.org/. The deal in deal.II stands for Differential Equation Analysis Library. It's written in C++, makes heavy use of templates and been in development since 2000. It's not meant for solid mechanics or fluid mechanics specifically, but for FEM solutions of general PDEs. The documentation is vast, the examples are numerous and the library interfaces with other libraries like Petsc, Trilinos etc. You can output results to a variety of formats. I believe support for triangle and tetrahedral elements has been added only recently. In spite of this, one quirk of the library is that meshes are called "triangulations".

class3shock 2y ago

Abaqus is up there with Ansys aswell as others have mentioned.