Local energy dissipation

Hello,

I try to simplify my question.
Is it possible to have the information about particles and contact (force, momentum, velocity, stiffenesses etc...) in a specific area of a numerical sample ?

Best regards.
Jabrane.

Hi Jabrane,

Is it possible to have the information about particles and contact (force,
> momentum, velocity, stiffenesses etc...) in a specific area of a numerical
> sample ?

of course:
forcesInCertainArea = [O.forces.f(b.id) for b in O.bodies if b.state.pos[2]
> 1.5] # to get forces from bodies with z coordinate > 1.5
avgForce = sum(forcesInCertainArea,Vector3.Zero) / len(forcesInCertainArea
# to average them

To get better answer about energies, please provide a MWE or specify more
in detail how you compute energy ("globally" does not really says much. Do
you use your own functions in Python? O.energy[...]?
Law2.someKindOfEnergy()? ......).

cheers
Jan

Hello Jan,

Thank you for your reaction.
I just don't understand what do you mean by "MWE".
May be my question is idiot but really i don't understand it.

Best regards
Jabrane.

https://yade-dem.org/wiki/Howtoask

Hello Jan,

Now i understand "MWE", thank you :-)

The "global" calculation of friction energy and cracks energy means that i calculate these components in all the sample's contact.
My goal is to calculate these energy components in the contact included in the part of the sample which i'm interesting.

These energy components are calculated in the souce files with these name: "totalSlipE" for the friction energy and "totalCracksE" for the cracks energy.
You find the source files in the links below:
JointedCohesiveFrictionalPM.cpp https://filex.univ-lorraine.fr/get?k=PzE9jgmEIEheUbiqOEb
JointedCohesiveFrictionalPM.hpp https://filex.univ-lorraine.fr/get?k=P8kvtWEW6baalMTMQPp

Best regards.
Jabrane

Hi Jabrane,

you can (just some brainstorming):
1) hard code some values to the code :-) not very good solution, but if you
know it in advance, it would make its job
2) create another member of the Law2, probably being a predicate and there
would be another computed value (apart from the global value, also "local"
value satisfying the predicate condition would be computed
3) The values of dissipated energy would not be only added to some global
value, but stored individually for each interaction.
4) From python, you can somehow store values from previous step and with
the values from the current step, you can perform computation according to
the same equations, but only at certain location.

Reading it again, I think 3) is the most clean and general approach.

cheers
Jan

Hi Jan,

I think that i have a good idea for this problem by introducing a new energetic component Ecracks_local in the source files like this
if (x1 < geom->contactPoint[0] < x2 and x3 < geom->contactPoint[1] < x4 and x5 < geom->contactPoint[1] < x6)
Ecracks_local+= 0.5(Fn*Fn/kn + Fs*Fs/ks)

i will try this.

Best regards.
Jabrane.

Hello Jan,

I implement the solution proposed in my precedent comment and it works very well.

That solved my question.

Best regards.
Jabrane.