On 7 June 2010 07:13, Luc Sibille <[email protected]> wrote:
> Hi, > > It is just to give some details about strain localization. I don't think > you need a menbrane to obtain shear band, it has already been found in a > rigid cubical box with the DEM, and experimentally on sand with the > apparatus TRITRI in lab. 3S-R. Experimentally they found that the shear band > was reflected on the rigid boundaries. > > About periodic boundaries, I think I have already seen shear band with > periodic boundaries, but shear band are somehow constraint since they have > to verify the periodicity. > If it is true that shear bands might be a natural phenomenon, then also with a PBC it is possible to see them. But I think you are right, Luc, that the constraint due to the periodicity could be a "problem". At least it would be almost impossible a study of the inclination of the bands, which would be inevitably affected by the periodicity. Janek, may I ask you how is your membrane going? I am just very curious, it would be much more than interesting to have it in Yade. thanks, Chiara > > Best, > > Luc > > Janek Kozicki a écrit : > > Hi, >> >> I'm thinking about implementing membrane in triaxial test, in order >> to be able to see localization due to internal shearing. >> >> questions: >> 1) was it done already by someone, and I missed this? >> >> 2) it is maybe not necessary, because periodic boundaries also allow >> to see localization due to shearing? (I doubt that, because the shift >> on one side is on different height than the shift on right side). >> >> I would do this in following way: detect which spheres are on the >> outer boundary (so they are touching the membrane), and push them >> inside with some force. >> >> To detect spheres that touch the membrane I will do a Delaunay >> triangulation of whole sample, with extra four points added. Each of >> those four points is on the exterior of the sample and is a >> "membrane point". Any sphere that gets connected through Delaunay >> with this point must be lying on the boundary and is in contact with >> membrane. >> >> do you have any comments on that? >> >> I suppose that eigen has Delaunay triangulation. Previously I was >> using wm3 for that. >> >> > -- > Luc Sibille > > Université de Nantes - Laboratoire GeM UMR CNRS > > IUT de Saint Nazaire > 58, rue Michel-Ange - BP 420 > 44606 Saint-Nazaire Cedex, France > > Tel: +33 (0)2 40 17 81 78 > > > _______________________________________________ > Mailing list: > https://launchpad.net/~yade-dev<https://launchpad.net/%7Eyade-dev> > Post to : [email protected] > Unsubscribe : > https://launchpad.net/~yade-dev<https://launchpad.net/%7Eyade-dev> > More help : https://help.launchpad.net/ListHelp >
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