yade-users team mailing list archive

[Bruno Chareyre <bruno.chareyre@xxxxxxxxxxx>]

Hi,

It is used in that sense, in the code I thougt the initial question was 
reffering to.
Sorry if the joke was obscure, I meant this naming was misleading.

One example in SimpleElasticRelationShip l.38 :

Real Va     = mat1->poisson;
Real Vb     = mat2->poisson;

Real Kn = 2*Ea*Da*Eb*Db/(Ea*Da+Eb*Db);
Real Ks = 2*Ea*Da*Va*Eb*Db*Vb/(Ea*Da*Va+Eb*Db*Va)

Which means :
kna = Ea/Da, knb = Eb/Db
ksa = poisson*kna, ksb = poisson*knb // ks = kn*nu

In short, if E, nu, and sizes are the same, it gives :

Kn = E/D, Ks=nu*Kn.

So, in the default triaxial test, what you put in the variable 
"spherePoissonRatio", is used to define ks/kn.
There is nothing wrong in the equations, for me at least, but I think 
I'll rename this parameter "alpha" in the TT interface, so we don't have 
confusion. I hope it clarifies the previous mail when I wrote this :

"For Poisson, the name is only due to the fact that Poisson's ratio 
depends mostly on ks/kn. But there is no constant - not even linear - 
relation between the micro and the macro in that case."

It means I named ks/kn "poisson" because it is the only variable (in the 
contact law) that can modify nu. There is no proportionality between 
ks/kn and nu, however.

I hope it clarifies. Sorry if I type too fast sometimes (I know I do it 
a lot). I'm not asking anybody to change this name, I'm saying I could 
change it.

Bruno




Václav Šmilauer a écrit :
> > > I never used ν in the sense of kt/kn...
> > >       
> > Yeah. We need to change the name. :)
> >     
> I am not aware of that name being use anywhere in this sense, am I
> missing something? (or an internal joke?)
>
> I don't smoke anything, I don't drink, and I have feeling that I have
> progressively more and more problems communicating with people over wire
> (ok, just with you: velGrad, now the simple shear thing, and this?!). I
> just listen to minimalistic music sometimes, but that shouldn't change
> the brains so much.
>
> v
>
>
>
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Chareyre Bruno
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