Yade

Multiple damping parameters

Asked by Bowman

Hi,
I'd like to model a bed of one material that periodically is impacted by a much softer material. Is it possible to define a damping for the hard bed material interactions and another damping for the softer material as it interacts with the hard bed? In other words the restitution for the hard/hard should be greater than the restitution for the soft/hard interactions. Thanks!

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Klaus Thoeni
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Anton Gladky (gladky-anton) said : 		#1

Hi,

for example, in ViscoelasticPM the damping coefficient is calculated
for the interaction like [1]:

phys->cn = (cn1?1/cn1:0) + (cn2?1/cn2:0); phys->cn = phys->cn?1/phys->cn:0;

it depends on the contact law, what you are going to use.

[1] https://github.com/yade/trunk/blob/master/pkg/dem/ViscoelasticPM.cpp#L57

Cheers,

Anton

2013/8/29 Bowman <email address hidden>:
> New question #234854 on Yade:
> https://answers.launchpad.net/yade/+question/234854
>
> Hi,
> I'd like to model a bed of one material that periodically is impacted by a much softer material. Is it possible to define a damping for the hard bed material interactions and another damping for the softer material as it interacts with the hard bed? In other words the restitution for the hard/hard should be greater than the restitution for the soft/hard interactions. Thanks!
>
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Revision history for this message
Best Klaus Thoeni (klaus.thoeni) said : 		#2

Hi,

some contact laws like HertzMindlin allow the use of MatchMaker, (see e.g.
examples/spheresFactory.py). It works as well with the damping coefficient cn,
e.g.:

cn=MatchMaker(matches=((steelId,shotsId,.4),(shotsId,shotsId,1)))

HTH
Klaus

On Thursday 29 August 2013 16:16:09 Bowman wrote:
> New question #234854 on Yade:
> https://answers.launchpad.net/yade/+question/234854
>
> Hi,
> I'd like to model a bed of one material that periodically is impacted by a
> much softer material. Is it possible to define a damping for the hard bed
> material interactions and another damping for the softer material as it
> interacts with the hard bed? In other words the restitution for the
> hard/hard should be greater than the restitution for the soft/hard
> interactions. Thanks!
>
> --
> You received this question notification because you are a member of
> yade-users, which is an answer contact for Yade.
>
> _______________________________________________
> Mailing list: https://launchpad.net/~yade-users
> Post to : <email address hidden>
> Unsubscribe : https://launchpad.net/~yade-users
> More help : https://help.launchpad.net/ListHelp

Revision history for this message
Bowman (bowmangotti) said : 		#3

Thanks Klaus Thoeni, that solved my question.