Hi all,
Form LIGGGHTS, I can output the contact forces acting on a selected particle in the soil assembly directly. Does anyone know whether LIGGGHTS can output the mean normal stress acting on a single particle and how to output this data? Some description of such mean normal stress (p'=sigma_ii'/3) can be seen in the attached picture.
Best,
Rachel
| Attachment | Size |
|---|---|
 mean_normal_stress.jpg | 132.34 KB |
paul | Tue, 06/05/2018 - 08:31
On a single-particle (contact
On a single-particle (contact) basis, you can get the contact forces (normal, tangential) using compute pair/gran/local:
https://www.cfdem.com/media/DEM/docu/compute_pair_gran_local.html
There is an example in the documentation how to output these forces.
I'd refrain from using compute stress/atom as it seems to be a vestigial compute from LAMMPS.
Rachel | Fri, 06/15/2018 - 09:40
Hi Paul,
Hi Paul,
Thanks for your reply. I have ever used the "compute pair/gran/local" command for the contact force. Do you mean I can output the stress using contact force/contacting area? What I want to obtain is the average stress acting on a particle. Would you have any ideas?
Best,
Rachel
paul | Fri, 06/15/2018 - 11:17
Yes that should be possible.
Yes that should be possible. I'd output the per-atom-per-contact wise contact area and force for using dump/mesh/gran/VTK and then calculate it in postprocessing.
Read the corresponding documentation https://www.cfdem.com/media/DEM/docu/compute_pair_gran_local.html - it is well-written IMO.