yade-dev team mailing list archive

[Anton Gladky <gladky.anton@xxxxxxxxx>]

Hi Francois,

I am ok with these changes.

Anton


2013/12/19 François <francois.kneib@xxxxxxxxx>:
> Hi,
>
> I'm currently dealing with handling the contact between a ViscElMat and a
> FrictMat.
> To do this, and as I said some days ago, ViscElMat will have a Young Modulus
> and Stiffnesses. If both are set by the user, young modulus will be ignored
> (so the actual scripts will still work).
>
> I'm wondering about massMultiply. By default it is True and the resulting
> stiffness of the contact is K=k1*m1*k2*m2/(k1*m1+k2*m2), and the viscous
> factors are multiplied by the mass too. If the user sets stiffnesses, I
> understand that the masses comes into consideration when computing the
> resulting stiffness. But to my mind, if the user sets Young/Poisson, then
> ki=2*Ei*ri and the "particles shapes" are already taken into account, so we
> should not use massMultiply. That's not true for the viscous coefficient
> that should be computed the same way if the user sets stiffnesses or
> young/poisson.
>
> What I propose in the case the user sets young/poisson and massMultiply=true
> is : don't multiply for the stiffness calculation, but multiply for the
> viscous coefficients. In addition, by doing this, the behaviour will be the
> same than for the FrictPhys, which seems essential.
>
> Do you agree with this ? Of course, all this modifications will be described
> in the documentation.
>
> François