yade-dev team mailing list archive

[Chiara Modenese <chiara.modenese@xxxxxxxxx>]

Hi Luc,
I think there is an issue as well since I am planning to use the new contact law with the triaxial and now I do not know whether to choose Dem3DofGeom or ScGeom. Any further suggestion on this side?
Thanks,

Chiara






----Messaggio originale----

Da: lscholtes63@xxxxxxxxx

Data: 29/01/2010 1.09

A: "yade-dev"<yade-dev@xxxxxxxxxxxxxxxxxxx>

Ogg: Re: [Yade-dev] ScGeom vs Dem3DofGeom



Not sure, but I think that there is an issue here.

Indeed, as Vaclav said, Dem3DofGeom has a proper representation of facet-sphere interaction compared to ScGeom, but, in the same time, the Triaxial Test (and it seems that you are planning to use it to test your contact law, like me) has to be used with Boxes (which are related to ScGeom) to avoid some errors in the calculation from what Bruno said in a previous mail.



In my case, I developed a contact law using Dem3DofGeom that I cannot test within the Triaxial. From what I understood, I have to rewrite my contact law with ScGeom to suit the Triaxial Test (something like a duplication of Law2_Dem3DogGeom_XXX to Law2_ScGeom_XXX with few changes in Ip2_XXXMat_XXXMat_XXXPhys?). 


Is this Dem3Dofgeom/Triaxialtest issue real or not? If yes, I would be pleased to try to do something. If not, please tell me where I am wrong.



Luc

BTW, I first faced this problem when I wanted to create the "triaxial cell "around one of my assembly with the yade.utils function aabbwalls which create boxes... 



2010/1/29 Václav Šmilauer <eudoxos@xxxxxxxx>




could you tell me which is in brief the difference between ScGeom and Dem3DofGeom?


ScGeom uses incremental computation of shear, whereas Dem3DofGeom uses total formulation. ScGeom replaces facet with sphere in facet-sphere contact, Dem3DofGeom has proper representation of facet with 0 thickness.



I was suggesting to refactor those 2 (i.e. write it properly and have the same interface for both incremental and non-incremental version (so that the law would be the same for both), but there was not much reaction...






BTW, about the naming for a new contact law, should I follow the convention Law2_>>_>>_>>, shouldn't I?


Yes, please

.


If I have new variables, could I include them in the FrictPhys class? 


Derive your own class from FrictPhys, just like e.g. CpmPhys does.




Should I use the virtual function go? I see that in the ElasticContactLaw used in the Triaxial we use the function action..


ElasticContactLaw is old engine that puts the interaction loop inside itself and internally calls the elastic LawFunctor anyway. It makes the code slower.



Instead, derive your class from LawFunctor and overrider the ::go method, which will always act on 1 interaction only. (Read https://www.yade-dem.org/sphinx/prog.html#multiple-dispatch, it can be useful although it gets in lots of details on the c++ side)





v



_______________________________________________

Mailing list: https://launchpad.net/~yade-dev

Post to     : yade-dev@xxxxxxxxxxxxxxxxxxx

Unsubscribe : https://launchpad.net/~yade-dev

More help   : https://help.launchpad.net/ListHelp