Ok, thank you all. Will try to test and calibrate it. ______________________________
Anton Gladkyy 2010/2/11 Václav Šmilauer <[email protected]> > What do you mean, cohesive shear force? You just change definition of > plasticity surface to get shear resistanace when the contact is in > tension. This is what you have currently: > > Real > maxFsSq=phys->normalForce.SquaredLength()*phys->tanFrictionAngle*phys->tanFrictionAngle; > > so you change that accordingly. In attachment, there are some plasticity > surfaces used in the concrete model. Those for ω=1 (damaged) carry no > cohesion (that is what you have now), undamaged (ω=0) ones do have > cohesion, which is what you need. (Horizontal axis is normal stress, > vertical is |shear stress|). (Disregard those log surfaces, they are not > relevant here) > > So if you go with this kind of linear plasticity surface, you need one > additional parameter (e.g. cohesion=max normal stress=x-coordinate of > the cone top): > > Real maxFs=max((Real)0.,cohesion-sigmaN*tanFrictionAngle); > if(sigmaT.SquaredLength()>maxFs*maxFs){ > // plastic slip > } > > See e.g. http://en.wikipedia.org/wiki/Yield_%28engineering%29, but they > have plasticity surfaces defined in terms of 3 principal stresses, > whereas we have to use formulation with σn vs. |σt| with DEM (at least > for 3 degrees of freedom of the contact), which corresponds to taking > σ₁=σn and σ₂=σ₃=|σt| (I think; never thought about that properly). > > Cheers, Vaclav > > > > > > Hi, > > > > I am trying to add "shear cohesive force" into the RockPM, as for now > > there are only normal cohesive forces. Has anybody an advice where to > > get such algorithm to escape write it from scratch? > > > > Thanks for all suggestions. > > ______________________________ > > > > Anton Gladkyy > > _______________________________________________ > > 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 > > > _______________________________________________ > 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 > >
_______________________________________________ Mailing list: https://launchpad.net/~yade-dev Post to : [email protected] Unsubscribe : https://launchpad.net/~yade-dev More help : https://help.launchpad.net/ListHelp
