might I ask how you know if your timestep is too large? do you compare your results with experiment? or are there funky results that you have learned to associate with time steps that are too big?
--- On Thu, 7/8/10, Anton Gladky <[email protected]> wrote: From: Anton Gladky <[email protected]> Subject: Re: [Yade-users] hello? -help with a spinning bucket! To: [email protected] Received: Thursday, July 8, 2010, 2:10 PM Hi, this is a more-less normal time step for simulations. Sometimes I have to do: O.dt = 0.1*pWavetimestep 2010/7/8 Michael Jensen <[email protected]> one thing that I would be particularly interested in is how the formula on this page: https://www.yade-dem.org/sphinx/yade.utils.html#yade.utils.PWaveTimeStep for spherepwavetimestep is computed. 2.8284271247461903e-07 is a very small number, meaning a huge number of iterations are required (almost 10 million) before a=20 single second goes by in the simulation. that's a hell of a lot of iterations! for one second! is it really necessary? -mike.. --- On Thu, 7/8/10, Bruno Chareyre <[email protected]> wrote: From: Bruno Chareyre <[email protected]> Subject: Re: [Yade-users] hello? -help with a spinning bucket! To: [email protected] Received: Thursday, July 8, 2010, 10:13 AM It seems to me that if I put some beads into a container, then tip the container, the angle at which they start flowing is the angle of internal friction.. I am not at all sure of this, it seems far to simple. Not really. Angle of repose corresponds to "internal packing friction", which "depends on" contact friction but is not equal. Most materials have contact friction around 30°. Put this value at contact in a loose sphere packing and you will get an internal friction around 18°. Anyway, you should get realistic results as soon as you define a decent friction (say between 10 and 40), this is not a crucial parameter yet. Bruno -----Inline Attachment Follows----- _______________________________________________ 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 -----Inline Attachment Follows----- _______________________________________________ Mailing list: https://launchpad.net/~yade-users Post to : [email protected] Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
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