Dumping Contact Forces

Submitted by alexander.polson on Fri, 07/09/2010 - 11:54

Hi Everyone

The "dump custom" has the option for writing "fx fy fz". I assume these are the resultant total unbalanced force per sphere.

Is it possible to dump the contact forces (between spheres) and the contacts' positions?

Thank you

Alexander

Forums:

ckloss's picture

ckloss | Fri, 07/09/2010 - 11:58

Hi Alexander,

yes, fx, fy, fz is the total force on a sphere (comprising particle and wall contacts, gravity etc.)
Currently, such a contact chain feature is not implemented - but it could be developed on request

Best,
Christoph

alexander.polson | Mon, 07/12/2010 - 12:59

Hi Christoph

Such a feature would be very useful to me and, I think, other users too.

E.g. if you want to get the torque needed (or energy consumed) for turning a drum filled with particles, or the force caused by the spheres against a structure.

Do you have a procedure for feature requests, or is this it?

Thank you!

Kind regards

Alexander

ckloss's picture

ckloss | Mon, 07/12/2010 - 14:34

Hi Alex,

>>Such a feature would be very useful to me and, I think, other users too.
Agreed

>>E.g. if you want to get the torque needed (or energy consumed) for turning a drum filled with particles, or the force >>caused by the spheres against a structure.

That is surely possible

>>Do you have a procedure for feature requests, or is this it?
If you have something concrete in mind, send me an email and we will talk about it!

Best,
Christoph

Silias | Thu, 09/01/2011 - 13:38

Hi Christoph,

is there a chance, that this feature will be implemented in the near future in a public release?

If not, could you shortly outline the steps which have to be taken to implement such a feature and which files are concerned?

Thanks,
Sebastian

ckloss's picture

ckloss | Thu, 09/01/2011 - 13:43

that is already implemented, see compute pair/gran/local (for p-p contact forces) and fix mesh/gran/stressanalysis (for total force/torque on body)
However, pizza.py does currently not support converting this data into VTK, so you would have to do this on your own or check out what Mark Bentley coded, see here: node/393
Christoph