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Re: Undrained Traiaxial Test

 

Thanks Luc !



Le mardi 20 avril 2010 à 11:09 +0200, Luc SIBILLE a écrit :
> Hi Nejib,
> 
> You cannot do that directly with the 3DTriaxialEngine, you need to modify
> it to perform the following thing:
> 
> 1/compute de radial stress sigma_r (there is a function for that in
> TriaxialStressController).
> 2/ adjust the axial stress sigma_a such that sigma_a = q - sigma_r, where
> q is the value of the deviatoric stress you want to impose for your stress
> control.
> 3/ finally impose the radial strain epsilon_r to verify the undrained
> condition with epsilon_r = - epsilon_a / 2.
> 
> Best,
> 
>   Luc
> 
> >
> > Controlling in strains only does not lead the specimen to a brutal
> > failure, I want to see what happens to the specimen if I add a small
> > axial load at a given state of the unstable zone.
> >
> >
> >
> >
> >
> > Le jeudi 15 avril 2010 à 18:46 +0200, Jerome Duriez a écrit :
> >> I would say that the simplest is to control in strain only (set
> >> stressControl_1=stressControl_2=stressControl_3=False), and to set
> >> directly values of strain_rate1, strain_rate2, strain_rate3 such that
> >> strain_rate1+strain_rate2+strain_rate3=0
> >>
> >> What do you think about this ?
> >>
> >> Jerome
> >>
> >>
> >> nejib hadda a écrit :
> >> > Hi Jerome,
> >> >
> >> >   I'm using the ThreeDtriaxialengine, and it gives the possibility to
> >> > control in stress and strain at the same time. And using your notation
> >> > downhere, I would like to make E22 and E33 follow E11 in such a way
> >> that
> >> > Ev=0.
> >> >
> >> >
> >> > Le jeudi 15 avril 2010 à 16:04 +0200, Jerome Duriez a écrit :
> >> >
> >> > > Hello Nejib,
> >> > >  From a general point of view if we note 1(=axial for ex), 2,3
> >> > > (=laterals) the directions of the space, L1, L2, L3 the size of your
> >> > > specimen in these three directions, and v1, v2 and v3 the speeds at
> >> > > which you displace your walls in these three directions I would say
> >> that
> >> > > you will be at a constant volume if you keep v1/L1 + v2/L2 + v3/L3
> >> =0
> >> > > (No more stress control by this way, your test will be fully strain
> >> > > controlled)
> >> > >
> >> > > Jerome
> >> > >
> >> > > nejib hadda a écrit :
> >> > >
> >> > > > Hi,
> >> > > >
> >> > > > I like to make the sum of the lateral strains equal to the
> >> opposite of
> >> > > > the axial strain so that the volumetric strain is null (Undrained
> >> > > > triaial test).
> >> > > > stains' computing depend on the 3 axes, is it possible to compute
> >> the
> >> > > > lateral strains function of the axial one (stress controlled) or
> >> it
> >> > > > would have an impact on the results?
> >> > > >
> >> > > > if not, I'll appreciate any other alternative to perform an
> >> undrained
> >> > > > triaxial test.
> >> > > >
> >> > > > thanks
> >> > > >
> >> > > >
> >> > > >
> >> > > > _______________________________________________
> >> > > > Mailing list: https://launchpad.net/~yade-users
> >> > > > Post to     : yade-users@xxxxxxxxxxxxxxxxxxx
> >> > > > Unsubscribe : https://launchpad.net/~yade-users
> >> > > > More help   : https://help.launchpad.net/ListHelp
> >> > > >
> >> > > >
> >> > > >
> >> >
> >> >
> >>
> >> --
> >> Jérôme Duriez
> >> ATER Iut 1 Grenoble, département GMP - Laboratoire 3S-R
> >> 04.56.52.86.49 (ne pas laisser de messages sur le répondeur)
> >> _______________________________________________
> >> Mailing list: https://launchpad.net/~yade-users
> >> Post to     : yade-users@xxxxxxxxxxxxxxxxxxx
> >> Unsubscribe : https://launchpad.net/~yade-users
> >> More help   : https://help.launchpad.net/ListHelp
> >
> >
> > _______________________________________________
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> >
> 
> 




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