Dear all,
I am facing a problem about atoms passing through the stl meshes. In my originial code, I set the young's module of particles to be 5e6 Pa and that of mesh walls to be 1e9 Pa, everything goes well in this code. However, when I want to simulate a harder particles with Young's module being 7e7 Pa, the particles will passing through the mesh wall when I exert confining pressure on the particles. I guess it is because the particles is too hard and the mesh wall cannot stand this, so I change the Young's module of walls to be 1e11 Pa, while the result is similar.
Therefore, I want to ask how to keep the particles to be within the range of the mesh walls without peneration? Will the results vary significantly if I just use the small Young's module of particles? Many thanks.
Regards,
Rachel
paul | Thu, 11/16/2017 - 19:13
Have you reduced the timestep
Have you reduced the timestep? Do you satifsfy the Rayleigh criterion?
Numerical walls do not break, they can stand pretty much everything. A large timestep however will cause huge contact forces and subsequent ejection of particles out of the system. A large timestep with high particle velocity will also cause particles to cross walls as then they pass without calculation of contact forces.
Try not to use too hard particles and walls, they tend to slow down your simulations a lot.
Check out the work of van Lommen for exhaustive advice on this.