Re: [Yade-users] [Question #683934]: Bond broken and non movement of cohesive particles
Question #683934 on Yade changed: https://answers.launchpad.net/yade/+question/683934 Status: Needs information => Open Akm gave more information on the question: Hi Jan, Thanks for the call. But if I do not use the gts surface, then the essence of the question will be lost. I will try to upload an MWE though. -- 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 #683687]: Unable to save/reload FlowEngine scene
Question #683687 on Yade changed: https://answers.launchpad.net/yade/+question/683687 Robert Caulk posted a new comment: >Nevertheless history-independent problems (such as incompressible flow) will still work, since a new mesh will be created on reload, and it's just fine. The simple example I provide in #2 is incompressible flow and it does not readily work. No doubt, there are some mechanisms that still need to be developed and bug tested to make that work. -- 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 #683967]: GlobalStiffnessTimeStepper with Potential Blocks
Question #683967 on Yade changed: https://answers.launchpad.net/yade/+question/683967 Vasileios Angelidakis confirmed that the question is solved: Thanks Bruno Chareyre, that solved my question. -- 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 #683967]: GlobalStiffnessTimeStepper with Potential Blocks
Question #683967 on Yade changed: https://answers.launchpad.net/yade/+question/683967 Status: Answered => Solved Vasileios Angelidakis confirmed that the question is solved: Hi Bruno, Many thanks for your reply. This indeed sounds simpler. The idea of having the same units for kn, ks in every contact model sounds more straightforward too. I will update the KnKsPBLaw.cpp script to do that. Cheers, Vasileios -- 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 #683967]: GlobalStiffnessTimeStepper with Potential Blocks
Question #683967 on Yade changed: https://answers.launchpad.net/yade/+question/683967 Bruno Chareyre posted a new comment: In other words: 1/ rename the current kn, ks [force/volume] differently (automatic search replace), say volKn and volKs 2/ introduce new attributes named kn, ks, and assign relevant values to them. They'll be picked up by GSTS. -- 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 #683687]: Unable to save/reload FlowEngine scene
Question #683687 on Yade changed: https://answers.launchpad.net/yade/+question/683687 Bruno Chareyre posted a new comment: For future reference: history-dependent problems (such as heat transfer) will not play well with save/load since, indeed, field data written in the triangulation will be lost. Nevertheless history-independent problems (such as incompressible flow) will still work, since a new mesh will be created on reload, and it's just fine. -- 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 #683967]: GlobalStiffnessTimeStepper with Potential Blocks
Question #683967 on Yade changed: https://answers.launchpad.net/yade/+question/683967 Status: Open => Answered Bruno Chareyre proposed the following answer: Hi, We got a similar situation some time ago with Hertzian models. Their tangent stiffness (kn=dfn/dun) depends on the normal force itself, and it's actually not needed when calculating the contact force. The solution was as follows, by far the simpler: - reserve attributes "kn" and "ks" to reflect the derivatives dfn/dun and dft/dut (can be updated by the law functor) to be used by GSTS, and compute them just in order to determine stability condition. - give other names to any other stiffness used when actually computing the contact forces. I would suggest the same approach. This way GSTS will work as is with every contact model, provided that kn, ks always have the same meaning. If would start to introduce conditionals in GSTS to specialize it, OTOH, it will soon be a big mess. Bruno -- 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 #683967]: GlobalStiffnessTimeStepper with Potential Blocks
Question #683967 on Yade changed: https://answers.launchpad.net/yade/+question/683967 Vasileios Angelidakis gave more information on the question: Hi, Thank you both for your advice! Robert, > Is it over estimating the time step, resulting in instability? - Yes, currently the GlobalStiffnessTimeStepper can lead to instability, by overestimating the timestep. In particular, if we consider the cases where the contactArea > 1.0 (mm^2 or cm^2 or m^2), the timestep we currently get can be orders of magnitude larger than what it should be, if we considered the actual stiffness of the system. > are other people depending on the code being the way it is now? - I do not think anyone else currently uses the GlobalStiffnessTimeStepper with the Potential Blocks, so this shouldn't create any backward compatibility problems. If someone used it, we would have heard about this problem by now :) Jan, thanks for the step-by step advice > separate the code into another function This is a good point, in order to not slow down the engine for those who use it with spheres. I only have one reservation: If we separate the code into another function, we will be able to use the GlobalStiffnessTimeStepper efficiently only for models with one contact physics type. Now, in my case, the Potential Blocks only interact with themselves, so this is not a problem for me. But, if we wanted to use the GlobalStiffnessTimeStepper in a model with: Spheres+Polyhedra (for which the stiffnesses "phys->kn" and "phys->ks" are also expressed in different units than [N/m]), we would need to deal with both shapes in the same timestepper. I think an integrated solution would be to have one function, in which we iterate for each interaction, and depending on the type of the physics involved, calculate the stiffness of the interaction. -- 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 #683967]: GlobalStiffnessTimeStepper with Potential Blocks
Question #683967 on Yade changed: https://answers.launchpad.net/yade/+question/683967 Janek Kozicki posted a new comment: How about this: 1. reorganize a little bit GlobalStiffnessTimeStepper in following manner: 1.1. separate the code into another function which takes as an argument the [N/m] parameters, then returns the value. 1.2. The original code in GlobalStiffnessTimeStepper only calls this function with previously used [N/m] parameters 2. Then call the same function with your [N/m^3] values multiplied by contact area. Now the question is if it is better to derive from class GlobalStiffnessTimeStepper, and call that function in parent class. Or maybe if it’s better to handle all cases already in GlobalStiffnessTimeStepper, distinguishing between the N/m and N/m^3. -- 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 #682290]: the correct use of collider.avoidSelfInteractionMask ?
Question #682290 on Yade changed: https://answers.launchpad.net/yade/+question/682290 Status: Open => Expired Launchpad Janitor expired the question: This question was expired because it remained in the 'Open' state without activity for the last 15 days. -- 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 #683384]: After deletion of particles, why the output of particle number remains unchanged
Question #683384 on Yade changed: https://answers.launchpad.net/yade/+question/683384 Status: Answered => Solved zheng confirmed that the question is solved: Thanks Robert Caulk, that solved my question. -- 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 #683981]: What does 'rMean=-1' mean
Question #683981 on Yade changed: https://answers.launchpad.net/yade/+question/683981 Status: Answered => Solved Leonard confirmed that the question is solved: Thanks Robert Caulk, that solved my question. -- 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 #683949]: particle position data
Question #683949 on Yade changed: https://answers.launchpad.net/yade/+question/683949 Status: Open => Needs information Jan Stránský requested more information: Hello, I have tried your code (using Yade 2018.02b), but found no "weird data" (did not try too much, thought).. Please be more specific (I don't want to check 2500 lines of data file to find one discrepancy :-) It would help, if you could create a MWE [1], i.e. minimal from point of both code and simulation (number of particles, running time). cheers Jan [1] https://www.yade-dem.org/wiki/Howtoask -- 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 #683981]: What does 'rMean=-1' mean
Question #683981 on Yade changed: https://answers.launchpad.net/yade/+question/683981 Status: Open => Answered Robert Caulk proposed the following answer: It is the default value passed to the function in the case that the user does not provide it. In this case '-1' is essentially a flag to direct the algorithm toward one of the four described methods of sphere radius distribution specification. -- 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 #683967]: GlobalStiffnessTimeStepper with Potential Blocks
Question #683967 on Yade changed: https://answers.launchpad.net/yade/+question/683967 Robert Caulk posted a new comment: > Do you think this would slow down the engine or find any theoretical drawbacks? If it is just a single logical operator checking the for a potentialblock, the engine won't slow down. From a units standpoint, what you suggest makes more sense. I guess I just have two questions: - what is currently happening when you GlobalSitffnessTimeStepper with potential blocks? Is it over estimating the time step, resulting in instability? If not, the change you suggest will simply decrease the estimated time step which will slow down yours (and maybe others) simulations. - are other people depending on the code being the way it is now? (I guess no, but you know better than me) -rc -- 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
[Yade-users] [Question #683981]: What does 'rMean=-1' mean
New question #683981 on Yade: https://answers.launchpad.net/yade/+question/683981 Hi, I'd like to ask a stupid question about the meaning of ' someValue = -1', for example, in makeCloud [1], what does 'rMean=-1' and 'num=-1' mean? Thanks Leonard [1] https://yade-dev.gitlab.io/trunk/yade.pack.html?highlight=sp%20makecloud#yade._packSpheres.SpherePack.makeCloud -- 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
