yade-users team mailing list archive

[Bruno Chareyre <bruno.chareyre@xxxxxxxxxxx>]

Hello Liqing,

You are right on the fact that there is no plastic limit for moment in 
current law. The calculation of moment itself however (say, elastic 
rotation-moment law) should be the same as in Plassiard et al., only the 
threshold is missing.
Moment will not exactly act all the time, it will act as long as shear 
or tensile strength are not exceeded, then the contact is broken and 
there is no moment anymore.
It would be nice to implement the plastic limit on moment. Feel free to 
do that (maybe using CohesiveFrictionalPM as an exemple, or maybe you 
will use this one straight away?) and ping us for integrating the change 
in the sources.
Making the default threshold "infinite" will not change the default 
behaviour and cannot hurt anybody.

Cheers.

Bruno


On 16/09/10 12:40, ?????? wrote:
> Hello,
>
> I found the moment calculation in cohesion-friction model is different 
> from the traditional algorithm which is listed in the 
> paper(Jean-Patrick Plassiard etl, A spherical discrete element 
> model:calibration procedure and incremental response, 209; N. Belheine 
> etl, Numerial simulation of drained triaxial test using 3d discrete 
> element modeling; Rolling resistance at contacts in simulation of 
> shear band development by DEM). In the traditional algorithms, the 
> slider for rolling starts working if the moment exceeds a value of 
> "eta* Normal force". However, I cannot find the related code described 
> it. If no any condition to relax the moment. then the moment will act 
> all the time. I think it should be wrong. Maybe I haven't found the 
> right file. May I have your help? Thank you.
>
> Best
> Liqing
>
>
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--
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Bruno Chareyre
Associate Professor
ENSE^(3) - Grenoble INP
Lab. 3SR
BP 53 - 38041, Grenoble cedex 9 - France
T??l : +33 4 56 52 86 21
Fax : +33 4 76 82 70 43
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