yade-users team mailing list archive

[Jan Stránský <question290372@xxxxxxxxxxxxxxxxxxxxx>]

Question #290372 on Yade changed:
https://answers.launchpad.net/yade/+question/290372

Jan Stránský proposed the following answer:
Hi Mohsen,
you are correct, the approach I proposed works only for existing
interactions but does not make sense in simulations with new interactions.
I think the easiest way is to change how E is computed (or make some
option). How should your formula look like? Harmonic mean like [1]? Then in
your case would E=(2*1e6*1e12)/(1e6+1e12)=2e6.
I will do the changes and commit in a few days
cheers
Jan
[1] https://yade-dem.org/doc/formulation.html#normal-stiffness


2016-04-12 7:52 GMT+02:00 mohsen <question290372@xxxxxxxxxxxxxxxxxxxxx>:

> Question #290372 on Yade changed:
> https://answers.launchpad.net/yade/+question/290372
>
> mohsen posted a new comment:
> in the case of larg number of particles, i think for each new
> interaction, computation follows Cpmphys functor; i.e. computing
> 'average' E. Therefore i should change 'E' by above formula in each
> iteration an for every interaction. So in my script where should i put
> the above 'for' loop?! For example for 1000 iterations is the following
> script true?
>
> #after defining scene and engines#
>  ii=1000
> while O.iter<ii
>   O.step()
>   for i in O.interactions:
>     mat1 = O.bodies[i.id1].mat
>     mat2 = O.bodies[i.id2].mat
>     E1,E2 = mat1.young, mat2.young
>     i.phys.E = whatever(E1,E2)
>     i.phys.kn = pi*pow(i.crossSection,2)*i.phys.E / i.phys.refLength
> ######
>
> i think all forces first are computed according to Cpmphys functor and
> then the interaction parameters changed. So changing interaction parameters
> does affects?!
>
> --
> You received this question notification because your team yade-users is
> an answer contact for Yade.
>
> _______________________________________________
> Mailing list: https://launchpad.net/~yade-users
> Post to     : yade-users@xxxxxxxxxxxxxxxxxxx
> Unsubscribe : https://launchpad.net/~yade-users
> More help   : https://help.launchpad.net/ListHelp
>

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