Re: [Yade-users] [Question #699714]: Python problems in Yade 2021.01a
Question #699714 on Yade changed: https://answers.launchpad.net/yade/+question/699714 Jan Stránský posted a new comment: Nice catch. I confirming the issue with yadedaily, too. Cheers Jan -- You received this question notification because your team yade-users is an answer contact for Yade. ___ Mailing list: https://launchpad.net/~yade-users Post to : yade-users@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
Re: [Yade-users] [Question #699714]: Python problems in Yade 2021.01a
Question #699714 on Yade changed: https://answers.launchpad.net/yade/+question/699714 Status: Open => Answered Jan Stránský proposed the following answer: It is a known issue that Yade terminal has some problems with scopes, maybe this is related to that. If you put the code in a script and run the script, it should works OK (works OK in my yadedaily). Cheers Jan -- You received this question notification because your team yade-users is an answer contact for Yade. ___ Mailing list: https://launchpad.net/~yade-users Post to : yade-users@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
Re: [Yade-users] [Question #699705]: Empirical value of rolling stiffness (Krot)
Question #699705 on Yade changed: https://answers.launchpad.net/yade/+question/699705 Status: Open => Answered Karol Brzezinski proposed the following answer: Hi, to be honest I thought so until now. Probably the best way to answer this question would be to study the source code. I believe that you can find the answer here: CPM: https://gitlab.com/yade-dev/trunk/-/blob/master/pkg/dem/CohesiveFrictionalContactLaw.cpp#L307 Hertz-Mindlin: https://gitlab.com/yade-dev/trunk/-/blob/master/pkg/dem/HertzMindlin.cpp#L67 https://gitlab.com/yade-dev/trunk/-/blob/master/pkg/dem/HertzMindlin.cpp#L535 It looks like CPM uses dimensionless rolling stiffness as you stated, but the Hertz-Mindlin model only takes 'krot' that is not related to other stiffness parameters, and then computes moment directly based krot and relative rotation. Best wishes, Karol -- You received this question notification because your team yade-users is an answer contact for Yade. ___ Mailing list: https://launchpad.net/~yade-users Post to : yade-users@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
Re: [Yade-users] [Question #699705]: Empirical value of rolling stiffness (Krot)
Question #699705 on Yade changed: https://answers.launchpad.net/yade/+question/699705 Zhicheng Gao posted a new comment: Another problem is how to distinguish between ball-to-ball contact and ball-to-wall contact, the material of balls and walls are all both FrictMat. And, for the Hertz-Mindlin contact law, only the Ip2_FrictMat_FrictMat_MindlinPhys of IPhysFunctor and Law2_ScGeom_MindlinPhys_Mindlin of LawFunctor can be used, ie InteractionLoop( [Ig2_Sphere_Sphere_ScGeom(),Ig2_Box_Sphere_ScGeom6D()], [Ip2_FrictMat_FrictMat_MindlinPhys(en=en,eta=eta,krot=krot),Ip2_FrictMat_FrictMat_MindlinPhys(en=en)], [Law2_ScGeom_MindlinPhys_Mindlin()], So how to distinguish between ball-ball contact and ball-wall contact, so that the contact between the wall and the ball is set to be frictionless and anti-rotational. -- You received this question notification because your team yade-users is an answer contact for Yade. ___ Mailing list: https://launchpad.net/~yade-users Post to : yade-users@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
Re: [Yade-users] [Question #699705]: Empirical value of rolling stiffness (Krot)
Question #699705 on Yade changed: https://answers.launchpad.net/yade/+question/699705 Status: Answered => Open Zhicheng Gao is still having a problem: Then how to distinguish between ball-to-ball contact and ball-to-wall contact -- You received this question notification because your team yade-users is an answer contact for Yade. ___ Mailing list: https://launchpad.net/~yade-users Post to : yade-users@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
Re: [Yade-users] [Question #699705]: Empirical value of rolling stiffness (Krot)
Question #699705 on Yade changed: https://answers.launchpad.net/yade/+question/699705 Karol Brzezinski posted a new comment: Hi, As far as I understand this (please bear in mind that I am not a Yade developer), 'krot' is something like a global parameter. In my opinion, it does not depend on contact geometry or material parameter, and (probably) it cannot be distinguished between walls and spheres. Cheers, Karol -- You received this question notification because your team yade-users is an answer contact for Yade. ___ Mailing list: https://launchpad.net/~yade-users Post to : yade-users@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
Re: [Yade-users] [Question #699705]: Empirical value of rolling stiffness (Krot)
Question #699705 on Yade changed: https://answers.launchpad.net/yade/+question/699705 Status: Open => Answered Jérôme Duriez proposed the following answer: Generally speaking about > how to distinguish between ball-to-ball contact and ball-to-wall contact assigning different FrictMat instance to spheres or walls will allow you to have different contact properties in such pairs, depending on the Ip2 calculations. For instance Ip2_FrictMat_FrictMat_FrictPhys computes by default contact friction angle as the minimum of both Material friction angles. You may have so-called MatchMaker to tune the behavior e.g. [*], but these are (at the moment) not available for every contact attribute / every Ip2. This being said, your present Ip2 looks to be singular in the sense it has a contact parameter directly as an Ip2 parameter, which is not the classical design and a clear drawback for your workflow. In this case, you have no other choice than manually looping over interactions and change parameters as you see fit. Fortunately, the Ip2 works only once at interaction creation so you won't have to do the same job twice for a given interaction (but it may still be painful because you have to continuously monitor new interactions. ) [*] https://yade- dem.org/doc/yade.wrapper.html#yade.wrapper.Ip2_FrictMat_FrictMat_FrictPhys.kn -- You received this question notification because your team yade-users is an answer contact for Yade. ___ Mailing list: https://launchpad.net/~yade-users Post to : yade-users@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
Re: [Yade-users] [Question #699698]: ERROR:root:Unable to guess python type from cxx type 'vector>
Question #699698 on Yade changed: https://answers.launchpad.net/yade/+question/699698 Status: Open => Answered Jérôme Duriez proposed the following answer: GUI inspector (though really nice) may not be able to render all simulation attributes i.e. safely guide them through the C++ / Python barrier, you have one example here. Your link [1] is another one. Fortunately, you can inspect manually from command line e.g. b = O.bodies[0] print(b.state.pos) same with engines see e.g. https://yade-dem.org/doc/tutorial-data- mining.html. I suspect it will give you access to what you wanna know about (which is usually not one of those things that can not make it from C++ to Python). -- You received this question notification because your team yade-users is an answer contact for Yade. ___ Mailing list: https://launchpad.net/~yade-users Post to : yade-users@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
