Yade

Material parameters of wall

Asked by Ziyu Wang

Dear all,
As a new user of yade, I have a question that seems very stupid about wall.
I have read several script using wall and I found that the parameters like frictionAngle and density is set to 0.So I take it for granted that the relevant parameters of the wall material should be set to 0.(It seems that I have also seen relevant information in Hands-on)
But when I read the script[1],the related parameters: Density is not 0.This confuses me.
Can anyone help me with this simple question?

Thanks for your help!
Best regards.

Question information

Language:
English Edit question
Status:
Solved
For:
Yade Edit question
Assignee:
No assignee Edit question
Solved by:
Ziyu Wang
Solved:
Last query:
Last reply:
Revision history for this message
Ziyu Wang (ziyuwang1) said : 		#1

Sorry, I forgot to attach the link to [1].
[1]https://gitlab.com/yade-dev/trunk/-/blob/master/examples/ThermalEngine/thermoHydroMechanical_coupling.py

Revision history for this message
Jan Stránský (honzik) said : 		#2

> Sorry, I forgot to attach the link to [1].

in that case, especially if there are no answers yet, you can edit the original question

Revision history for this message
Jan Stránský (honzik) said : 		#3

Hello,

> As a new user of yade

welcome :-)

TL;TR: use parameter suitable for your simulation and your needs. Not necessarily 0 (but might be 0).

> I have read several script

please try to reference specific script

> I found that the parameters like frictionAngle and density is set to 0.
> So I take it for granted that the relevant parameters of the wall material should be set to 0.
> (It seems that I have also seen relevant information in Hands-on)
> But when I read the script[1],the related parameters: Density is not 0.This confuses me.

No.
Take for granted, that the relevant parameters of the wall material should be set to the values according to your needs and according to your simulation.
Sometimes it might be 0, but definitely not necessarily.
It depends on your simulation, your model, your simplifications, your considerations, etc. etc.

E.g., if a wall is fixed, density does not matter (the value of density does not influence in any way the simulation).
Then density=0 may be set to emphasize this effect.

On the other hand, friction might be of significant importance.
Sometimes you want friction-less walls, then friction=0 makes sense.
Bot you might want to simulate walls with very high coefficient of friction / friction angle, so then 0 would not be a good choice.
Concerning friction angle, one might want to use MatchMaker of Ip2 [2,3] to make the choice of the resulting interaction friction more "relevant".

Also young parameter is of a big importance.
E.g. you can simulate something like perfectly rigid walls (with infinite stiffness). Or you have softer walls with defined stiffness. Or ...

Cheers
Jan

[2] https://yade-dem.org/doc/yade.wrapper.html#yade.wrapper.Ip2_FrictMat_FrictMat_FrictPhys.frictAngle
[3] https://yade-dem.org/doc/yade.wrapper.html#yade.wrapper.MatchMaker

Revision history for this message
Ziyu Wang (ziyuwang1) said : 		#4

Thanks Jan , that solved my problem.