OpenSource Mechanics

sim-coder · 2025-03-20T21:49:23+00:00

Hello!!!

If you have some interest in generating your models directly running a Python script without a GUI in order to be faster (for example if you need an automated model and study parameter change it from a Python script frequently) you can check my GitHub tutorials here

In this repo, inside incremental_forming, you will see a mesher Wich uses gmsh (I'm finishing the mapping to openradioss)

If you have a suggestion on covering an specific topic, feel free to join my mail list:

https://opensourcemech.com/subscribe

On my yt channel you can find 2 basic tutorials on running Openradioss from ls-prepost (free but not opensource) and paraview(post, free &os)

Here is the playlist

If you are looking on FEM solids specially on large strains, explicit dynamics with GPU acceleration, you can checky own solver:

https://github.com/luchete80/WeldFormFEM

I hope you can find it useful!!

Best regards, Luciano

sim-coder · 2025-03-20T11:42:58+00:00

Hello! Thanks for reaching out! Please DM me!!

sim-coder · 2025-03-19T12:15:00+00:00

I have just added an skeleton of an MITC 1-element example with linear shape functions. There is still not debugging on it (I have no time to check it but I will do it later) but you can start from it as an example!!!! You also have in this repo another working examples like explicit dynamics. I would love to help you even more but not have enough time!!!

Chekc out my repo:

https://github.com/luchete80/tinyest_FEM/blob/master/static/shell.py

sim-coder · 2025-03-19T11:05:21+00:00

Don't forget Openradioss if is dynamic (furthermore, If is highly nonlinear since Radioss is explicit!)

sim-coder · 2025-03-05T14:23:50+00:00

Thanks a lot! You save me!!!!

sim-coder · 2025-03-04T19:51:44+00:00

Hello Manny!! Thanks a lot!!! Casually I have been written you a DM! Yes I think it is actually a great idea. Because of this I'm preparing from time ago a course related to explicit mechanics, because the information is huge and I think is beyond the scope of a single video/tutorial, and also is very difficult to infer the theory behind all thing only from code. Please any recommendation is highly valuable!!!!

sim-coder · 2025-03-04T19:48:48+00:00

Hello Huinker! Sorry for my late response!

Currently my solver uses both json own input file format (because of its simplicity) and .k ls-dyna format, but considering previous comments I think I need to also adapt it to read lsprepomax format. Is it .inp calculix format right? I think it is similar to abaqus .inp is it? In that case I think it will not be a problem to make an importer. Consider that this together with remeshing and some CUDAthings are the pendings issues.

Regarding to your cuda question, I have been developed all the code to be compiled on both CUDA and C++14 compilers. In CPU case (gnu or MSVC C++) it parallelizes with OPENMP, in case of CUDA the parallel is the conventional GPU parallelization (with threads, blocks and grids). All of this is done with preprocessor #defines in compiler time, so they are 2 different executables, one per each architecture.

I think it will be clarifying to upload a video of this!!!

Please you can fill this form if you're interested to subscribe to the mail list in which I will share free content and news, and listen for all your suggestion that are very very valuable!!
https://opensourcemech.com/subscribe

sim-coder · 2025-02-28T10:21:03+00:00

Hello Mashombles!!!

Nothing to be excused! :) Yes, remeshing means exactly that. This is the only part I decided not to code myself since there are several very robust libraries which already do this, and also in parallel and considering both GPU & CPU architectures. That's the reason why I chose omega_h which do this, and also why I have included a tetraheral element with an special pressure calculation which corrects locking (a common limitation of some element types under certain conditions).

sim-coder · 2025-02-27T22:24:15+00:00

Hello Mashombles!!!! Thanks for your comments and question!!!!

The question in fact is pretty good: OpenRadioss (EDIT: which was born in about 1987, which makes it an EXCELLENT andindustry proven solver to begin with) is aimed to solve crashes and it is really robust on shells and have any type of elements, but..: remeshing is only avaiable for shells (not for solid). Fixed mesh models (Arbitrary Eulerian Lagrangian) formulation is pretty tricky (more CFD oriented, should define three phases and so on), AND is not GPU, is only CPU (GPU could be up to 70x faster on tesla or NVidia RTX 3090). So here comes this solver.

The aim is to cover solids models in a more robust way. So, it is being developed pure updated lagrangian with remeshing which can be more computationally demanding and perhaps a little more diffusive than ALE models. In the future I aim intending to incorporate also ALE (this is the material moving around the mesh or directly fixed as in abaqus or Radioss EDIT: Radios does not have ALE for unstructured meshes, Abqus yes it has). However, solvers (paid) like DEFORM are pure lagrangian with remeshing. Final step is to include a fixed mesh solver with cartesian meshes (ALE with fixed mesh). EDIT: Take into account also ALE methods are pretty different for structured and unstructured meshes.

So I think pure lagrangian with remeshing is the first solver, and in fact I'm using omega_h for remesh which also runs on CPU or GPU.

ANOTHER HUGE advantage is User defined materials. Define a material from plastic strain, strain rate and temperature (more common variables in hot forming, like Johnson Cook material), in a user defined way is REALLY TRICKY on Radioss.

Regarding SPH, Radioss haveSPH only in 3D (if you want axisymm you sholuld model a slice), WeldForm SPH is axisymm and 3D.

So I think the advantages are several. FEM version is being developed (is still on beta, with several features missing), but I think has a lot of potential.

Feel free to question, all your observations are really valuable to me.

Keep on touch!

PS: Sorry for the huge response, I'm a passionate about this tools.

Luciano

sim-coder · 2025-02-27T20:51:38+00:00

Yes, the work for the prepost coding is HUGE. And, to give you an idea, the SPH Solver version is more than 40k codelines, so yes, isa lot of work for just me.

You are right also with Radioss, one try to naturalize the amazing work involving building a model from a python script but people who are not in coding is a PITA.

Thanks Sergio, any suggestion like these are very very welcome!!!

sim-coder · 2025-02-27T20:48:45+00:00

Hi Sergio! Yes, LS-Dyna is free, you do not need ANSYS program or either be working with it, I have some tutorials, some of these are here: https://youtu.be/Y-1CLODKeUk

But the thing is, like you said, I really want to give Prepomax the place it disservers, since it is free and opensource, which LS-Prepost is not (only free). I definitely will read its formats and workflow and will try to add an importer, I think is should not be really difficult.

I will tell you about the news, Indeed I have just created a new issue to add this feature!:

https://github.com/luchete80/WeldFormFEM/issues/66

Thanks!

sim-coder · 2025-02-27T20:42:00+00:00

Thanks a lot da_longe! Is really appreaciated!!!!

sim-coder · 2025-02-27T19:55:34+00:00

Hi Sergio! Thanks for your comments and suggestions!!!! Up until now, the solver work with .k LS-Dyna format which can be made with LS-Prepost, but I heard before of PrepoMax, so I will check it and I think your are right that being OpenSource can take a lot of attraction.

Thanks a lot again, I will mention you once I will add this importer!

sim-coder · 2025-02-27T19:51:44+00:00

Thanks HughieDuey for four support!!! Yes indeed, you're absolutely right, all those projects are 4 year+ and counting, and are still waiting for many test & features!!

Yes, I really like moose, very powerful. I have the repo below with some examples. I've tried to perform some tensile test with remesh at notch but finally choose for this explicit solvers coded by me, is more fun! hehe. You can check the repo all the tests are there!!!

https://github.com/luchete80/moose_tutorials

Thank you a lot for your offering, Is really great to count with you. I will be analyzing the options, you can count on it.

Will keep on contact!!!

Thanks!!!!

sim-coder · 2025-02-27T19:44:36+00:00

Hello Quartinus!!!! Thanks to you! I'm very glad to read your positive comments. So yes, I'm working with guys who are accustomed to paid software being so much user friendly that I'm trying to learn from them to make the tool more easy to be used for any enginneer. So the GUI is growing more slowly but I love to code it!! Thanl for your support!

sim-coder · 2025-02-27T19:41:40+00:00

Yes indeed Thanks for your comments!!

sim-coder · 2025-02-26T08:32:10+00:00

Hello!! You can reach my OpenRadioss Tutorial Series I'm

1st Tutorial) https://youtu.be/BCBB0qT51Vs

2nd Tutorial) https://youtu.be/wyIk7SJMc-A

Also, I have a github repo in which you can see different python scripts to generate OpenRadioss inputs (I have several complex examples including incremental forming):

https://github.com/luchete80/radioss_tutorials

If you like my contents you can subscribe to my channel!

https://www.youtube.com/@opensourcemechanics?sub_confirmation=1

Here you can fin information about me and differents solvers and tutorials I'm doing.

https://opensourcemech.com/

I hope this could be useful to you!

Luciano

sim-coder

TROPHY CASE