yade-users team mailing list archive

[drasszkusz <question685836@xxxxxxxxxxxxxxxxxxxxx>]

Question #685836 on Yade changed:
https://answers.launchpad.net/yade/+question/685836

    Status: Open => Answered

drasszkusz proposed the following answer:
Hello,

> In [2], it asks to go to ''CohFrictPhys.cohesionDisablesFriction''
[3], it says "is shear strength the sum of friction and adhesion or only
adhesion? '' and the default value of [3] is false, does it mean that
when set it as false, the shear strength is the sum of friction and
adhesion?

Yes, if false, the shear strength is the sum of friction and adhesion.

> 3. Refer to ''CohFrictPhys.momentRotationLaw'' [4], [4] asks to go to ''Law2_ScGeom6D_CohFrictPhys_CohesionMoment::always_use_moment_law'' [5],
I choose false (defalt value) for the purpose of computing moments only for cohesive contacts. However, in ''Law2_ScGeom6D_CohFrictPhys_CohesionMoment'' [1], it says that ''Cohesive -type moment may also be included in the future'', it gives the feeling that Cohesive -type moment can not be achieved in this model currently, which makes me confused.

If false, it computes the rolling and twisting moments (controlled by
rolling and twisting resistance/friction coefficents aka etaRoll and
etaTwist) in case of active cohesive bonds between particles. This way
you can control the movement of the rolling  and twisting of particles
on/to each other. If it set to true, then it always calculates the
moments also if there is no cohesive connection between particles. This
way the particle shapes can be considered in numerical way, if the real
particles are not perfectly spherical. [1]

>By the way, I also reviewed some papers which worked based on
Law2_ScGeom6D_CohFrictPhys_CohesionMoment. In general, they didn't
consider cohesion and moment at the same time. This has deepened my
doubt about if cohesion and moment can be taken into at the same time in
terms of Law2_ScGeom6D_CohFrictPhys_CohesionMoment.

There are some papers considering both at the same time [2] [3]. In the
[3], you can find the mathematical background (equations) which are from
the source code.

Daniel

[1] https://www.sciencedirect.com/science/article/pii/S0020768318302567
[2] https://www.sciencedirect.com/science/article/pii/S0168169918316429
[3] page 272-282 https://mercurylab.co.uk/dem8/wp-content/uploads/sites/4/2019/07/263.pdf

-- 
You received this question notification because your team yade-users is
an answer contact for Yade.