2010/3/26 Bruno Chareyre <[email protected]> > > >> Actually I defined the normal stiffness as secant and the shear one as >> tangent. This because I was following PFC manual. But I see it is better to >> get both stiffnesses as tangent (I will modify it). So once I do that I can >> just pass those values to the GST, right? >> > GST will read kn/ks automaticaly. But be carefull, I'm not sure tangent > stiffness is the best way for computing the force itself, it introduces > approximations. The best would be to use an exact relation fn(un) for the > force, like in PFC, and define the derivatives (and call them "kn/ks") for > use in GST. > > > Ok, thanks for suggestions. You could be right, I will think about that. Actually for the normal direction I know where to look for (Hertz basically) but for the shear direction I have not really understood the formulation I found in PFC for the shear contact stiffness. Mindlin's paper seems complicated, moreover he makes distinction between the case with or withour slip, so that the tangential compliance changes. I will see to go into depth cause I need this formulation.
cheers, Chiara > Bruno > > _______________________________________________ > > Mailing list: > https://launchpad.net/~yade-users<https://launchpad.net/%7Eyade-users> > Post to : [email protected] > Unsubscribe : > https://launchpad.net/~yade-users<https://launchpad.net/%7Eyade-users> > > More help : https://help.launchpad.net/ListHelp >
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