yade-users team mailing list archive

[chiara modenese <c.modenese@xxxxxxxxx>]

On 25 March 2010 16:25, Bruno Chareyre <bruno.chareyre@xxxxxxxxxxx> wrote:

>
>
>> I think that the global damping (the one at the contact level) as it is
>> now implemented in Yade (class ViscoelastiPM) is wrong in the shear
>> direction.
>>
>>  There is confusion here. Global damping from Cundall is in Yade, but it
> is in Newton and independent on the contact law. It is not "shear" or
> "normal" because its applied on bodies.
> Here, you refer to viscous damping at contact, which is totally different.
> I would not mix both damping methods. Viscous is physical but not optimal in
> terms of cpu time. Global damping is numerical trick, but it is very
> efficient. By mixing them, you loose the advantage of each but you cumulate
> the drawbacks (not physical + suboptimal).
>


Ops, yes I was making reference just to the viscous damping at contact (so
we have shear and normal direction). Sorry if I called it global in this
discussion, it is just VISCOUS. Good to have it clear. I was not mixing
them, just testing the viscous one. I would not mix them too. Maybe it
depends on the nature of the problem whether to use the viscous damping or
the global one. The global does not depend on the velocities of the
particles so maybe for a dynamic problem viscous damping is a better choice.

chia

>
> Bruno
>
>
>
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