Open Source Mechanics

Suggested Adaptive Mesh refinement (w/Omega_h) and global remeshing (with MMG) technique:

Skip the Carousel

1 2

3 weeks ago | [YT] | 1

Open Source Mechanics

#FEM #TETRA #WeldForm #CUDA #GPU
Mores dvances in mesh adapting refinement using Omega_h!!!
Mapping of nodal variables is ready.
Also, now CPU version runs on Windows.
The first images shows only remeshing (w/o length parameters) if angle is between certain threshold. Now more control of quality is possible.
Also as in mmg library, we can map a variable to use as mesh size scale.

1 month ago | [YT] | 3

Open Source Mechanics

We are studying some cones produced with incremental forming. It results some 90 degree separated zones with similar deformations, so in order to be not affected by mesh influence, now we can generate with gmsh a "cylindrical" mesh so all elements are subfected to symmetric bending!!

Check it out :

github.com/luchete80/radioss_tutorials/tree/develo…

Skip the Carousel

1 2

1 month ago | [YT] | 1

Open Source Mechanics

Several advances in mesh adapting refinement using Omega_h!!!
Using element angles and element length to refine!!!

Maybe will be also incorporated mmg to compare!
At left are the original mesh with its plastic strain and at right are the new meshes with their the metrics.
Next: to map to new mesh and continue process!

#FEM #OMEGA_H #opensource

Skip the Carousel

1 2 3

1 month ago | [YT] | 4

Open Source Mechanics

20250311 - WeldFormFEM: Adding Adaptive Mesh Remefinement!!!
#FEM #CUDA #GPU
Begining to Add Adaptive Remeshing for GPU and CPU with omega_h library!!!

I really like Omega_h new coding style approach.
Mesh is succesfully built from current nodes and connectivities.

So, the thing is now to choose between Refine and Adapt Methods, I will begin with adapt in order to study element quality.

Skip the Carousel

1 2

1 month ago | [YT] | 4

Open Source Mechanics

If you have subscribed to opensourcemech mail list in 2025, please do it again if you want to receive news about courses and material!! Link was broken so I have this year list empty!! Thank you!!!

opensourcemech.com/subscribe.html

1 month ago | [YT] | 4

Open Source Mechanics

GPU FEM Solver almost working!

Writing fixes continues! Matrices calcDerivatives allocation was wrongly defined.
Problem was that in CUDA all Matrix ops and objects are defined in device but was using cudaMalloc & cudaFree functions, which are intender for using from host
Now is remaining to check that values are not consistent, but mem alloc were solved.
Next action will be to replace global calls entirely using omega_h library style function.


#FEM #HEXA #WeldForm #Hourglassing #CUDA #GPU

Skip the Carousel

1 2

1 month ago | [YT] | 4

Open Source Mechanics

Ok, Welcome to my Patreon!
www.patreon.com/posts/welcome-to-my-of-121747181?u…

Considering I'm building up code for about a dozen free opensource tools right now, including two main solvers (SPH and FEM with remeshing), both for CPU/CUDA architectures, a Graphical User interface, Several Python tools for radioss input, a general python educational FEMsolver, and so on (I own 70 repos), and I want to develop a lot of content tutorials and materials for several opensource software, and all this take A HUGE AMOUNT of time, I hope I could count with you on this!!!

You can also sign up as a free member!

Check it out:

Skip the Carousel

1 2

1 month ago (edited) | [YT] | 3

Open Source Mechanics

WeldFormFEM is gettin' bigger!!

Check it out and if you like it, give it a Star!!

github.com/luchete80/WeldFormFEM


WeldFormFEM Is an Updated Lagrangian Explicit Finite Element Method (FEM) CPU/GPU based solver.
WeldFormFEM is aimed to solve large strain metal forming like problems.
The idea is to work pure lagrangian with rezoning (adaptive mesh refinement) first and later to include also coupled eulerian ALE formulations.
WeldFormFEM works both on Ubuntu and Windows. you can select to build it to CPU and GPU only by changing a single CMAKE var.

Features

Explicit time integration

C++/CUDA CPU/GPU(WIP) Architectures

- Constant Stress Tetra/Triangle Element with Average Nodal Pressure (ANP) for volumetric locking fixing
- Reduced Integration Hexaheadra with viscous hourglass control
- OpenMP (WIP) CPU parallelization
- Contact algorithm (WIP)
- Automatic Remeshing (rezoning) (WIP)
- 2D Plain Strain/Axisymm & 3D
- Thermal-Mechanical coupling (WIP)



opensourcemech.com/

Aldo you can subscribe to my homepage!

3 months ago (edited) | [YT] | 2

Open Source Mechanics

20250116 - WeldFormFEM Tetras!!


Hi!!! News about WeldFormFEM CPU/GPU code:
- Thermal coupled is being written!!
- Adding remeshing "skeleton"..
- Adding volumetric locking treatement

I have found an excelent LS-Dyna Element behavior. Such Benson 1992 states, Constant Stress Tetra/Triangle (CST) behaves overly stiff, but he do not propose a solution.
HOWEVER, comercial FEM Forming tools like DEFORM, FORGE & qFORM (Simufact works with FVM in 3D), works with tetras. However Locking Locking behavior in CST or HEXA elements typically arises in specific contexts, such as incompressible or nearly incompressible material behavior, bending-dominated problems, or mesh refinement with ill-conditioned elements. This can be volumetric locking of shear locking. Bonet (who also has done and still doing an extensive work with SPH), propose to implement an average pressure to overcome locking.
Hourglass models (or Zero energy modes) only affects hexas, and are observed in reduced integration elements (1 gauss point), and are deformation states in which central element gauss point presents null value but nodes don't.
Regarding to Hexa locking, I will delay a little bit the coding (see 20241122 entry) since I thinnk Tetra is straightforward.


Check them in opensourcemech.com

#FEM #TETRA #HEXA #WeldForm #Hourglass #Locking

Skip the Carousel

1 2 3

3 months ago (edited) | [YT] | 2