You can use the engine ThreeDtriaxialEngine, with this engine you can choose to keep constant separatly S1, S2 and S3 at different values, like that the mean stress will stay constant. Is it enough for you, or do you want to keep the mean stress constant while S1, S2 and S3 are independently not constant?
Best, Luc > >> Now I want to >> do a simulation that I need to keep a mean stress ((S1+S2+S3)/3) >> constant, and >> Did anybody handle this before or how is it handled in YADE? can you >> give >> any suggestion? >> If YADE has already includes this kind of algorithm, can you tell me >> where is it? > > Hi Sayeed, > > to me it is not clear what are you trying to achieve. Can you be more > precise? > > In particle models, stress tensor is not defined, only forces on > interactions between particles; you can approximate stresses by looking > at interactions around each particle (which I did just recently for > postprocessing purposes in CpmStateUpdater::update, but only for the > concrete model). > > If you mean something like triaxial test where mean stress in the whole > specimen is constant, then you should have a look at > TriaxialStressController (that gives you ways to control individual > stress components) and derive your own engine from it. > > For periodic compression (simpler, since no walls and other funny > things, but less mature code otherwise), have a look at the > PeriIsoCompressor class; you would have to write something very similar, > just changing the lines that compute displacements to keep mean stress > constant. > > For those, you have to touch c++, though -- unless Bruno has some other > idea. > > Cheers, Vaclav > > > _______________________________________________ > Mailing list: https://launchpad.net/~yade-users > Post to : [email protected] > Unsubscribe : https://launchpad.net/~yade-users > More help : https://help.launchpad.net/ListHelp > _______________________________________________ Mailing list: https://launchpad.net/~yade-users Post to : [email protected] Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp

