On 10 May 2010 18:23, chiara modenese <[email protected]> wrote: > > > On 10 May 2010 18:03, chiara modenese <[email protected]> wrote: > >> >> >> On 10 May 2010 17:43, Bruno Chareyre <[email protected]> wrote: >> >>> >>> >>>> Hi Bruno, please see attached file. I am not completely sure but I think >>>> it would be correct to distinguish between loading and unloading phase. I >>>> am >>>> trying to prove it analytically, I am not yet totally confident.. What do >>>> you think? >>>> >>>> There is no trialFs in your figures, this is the key factor. >>> >>> us + (current-prev)/ks could make sense in some formulations if *=ratio >>> was applied _before,_ but it is applied _after, _so that "current" is in >>> fact the "trial" value (as you pointed out). >>> >>> OTOH, us is exactly (trialFs-prevFs)/ks, by definition of trialFs, >>> >> btw, us as you intend here is actually the total plastic displacement, not the incremental one. My delta_us I was referring to is an incremental one (and to me we need an incremental formulation here).
> (trialFs-currentFs)/ks is exactly the plastic part , >>> and (currentFs-prevFs)/ks is the elastic part. >>> >>> I don't see any difference between loading and unloading. >> >> >> I agree that the plastic displacement is (trialFs-currentFs)/ks. However >> your formulation is not incremental because you are using the trial value. >> To me this would be the right procedure only in the case in which shearForce >> is maintained constant. But shearForce is actually varying (right? Where do >> you account for this variation in your formula?) and as I sketched in my >> picture there is an elastic contribution that turns into plastic >> dissipation. Can you see my point? I will find out the analytical >> explanation. >> >> > When I say shearForce is varying I mean the maximum friction value. Maybe I > am a little confused now, perhaps I am wrong. Could you just tell me if you > see any effect due to the variation of the maximum friction? Because that is > why I was making distinction between loading and unloading and for the same > reason I am not convinced that using Trial force would be the best choice. > thanks, chiara > > >> 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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