Re: [Yade-users] [Question #702743]: Sensitivity testing: Results seem random
Question #702743 on Yade changed: https://answers.launchpad.net/yade/+question/702743 Status: Open => Answered Jan Stránský proposed the following answer: > 1) ... > Is there away to pack the spheres around my object to start? You can create the object in destination place and delete the undesired spheres > It appears my course material is the cause of a lot of my issues > I use such a course material to reduce computational expense. It is always a tradeoff.. 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 #702743]: Sensitivity testing: Results seem random
Question #702743 on Yade changed: https://answers.launchpad.net/yade/+question/702743 Status: Answered => Open Justin is still having a problem: Jan, 1) I push down because my object has a top, a rigid bracket, this can be seen in the photo I added to the google drive link (top_of_object.png). And, I didn't know another way to make sure the spheres would settle evenly. Because if I have the object in place before, the spheres would fall on top of the object and off to the side. Thus leaving the middle emptier compared to the sides. 2) You are correct, I just checked. The actual packing density (after gravity deposition) is different. 3) It was material density, and that's a good point. 4) Not parallel, it is single threaded. But this was good information, because I tried multicore in the past. And I did get different results running the same exact model. Thank you for clearing these issues up for me. It appears my course material is the cause of a lot of my issues. However, I use such a course material to reduce computational expense. Is there away to pack the spheres around my object to start? Thus I can by past pushing my object down into the spheres. Which appears to be a big cause of my issues, and is by far the most computationally expensive part of my model. Thanks, Justin -- 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 #702751]: periodic boundary in the direction of the length of a rotating drum (cylinder )
Question #702751 on Yade changed: https://answers.launchpad.net/yade/+question/702751 Status: Needs information => Open Roxana Saghafian Larijani gave more information on the question: Please find the MWE below: from yade import ymport from yade import pack from yade import utils, plot,wrapper fr = 0.38 rho = 2500 En = 0.7 Et = 0.7 poi=0.21 yoM=63e6 O.dt = 0.05 r = 0.01#0.002381 ##definig material mat=O.materials.append( ViscElCapMat(frictionAngle=fr, density=rho, poisson=poi, young= yoM,en=En, et=Et) ) #defining the spheres sp=pack.SpherePack() sp.makeCloud((0.6,0.6,0.05),(1,1,0.15),rMean=r) sp.toSimulation(material=mat) Nprtcl=len(O.bodies) Drum=geom.facetCylinder((0.8,0.8,0.1),radius=0.5,height=0.2,orientation=Quaternion(Vector3(0,0,1),(pi/2.0)), wallMask=4) walls = O.bodies.append(Drum) ##periodic boundary O.periodic = True O.cell.setBox(5,5,0.2) ##engine O.engines = [ ForceResetter(), InsertionSortCollider([Bo1_Sphere_Aabb(),Bo1_Facet_Aabb(),Bo1_Wall_Aabb()],allowBiggerThanPeriod = True), InteractionLoop( [Ig2_Sphere_Sphere_ScGeom(),Ig2_Facet_Sphere_ScGeom(),Ig2_Wall_Sphere_ScGeom()], [Ip2_ViscElCapMat_ViscElCapMat_ViscElCapPhys()], [Law2_ScGeom_ViscElCapPhys_Basic()], ), NewtonIntegrator(gravity=[0, -9.8, 0]), RotationEngine(ids=walls,rotationAxis=[0,0,1],rotateAroundZero=True,zeroPoint=[0.8,0.8,0.1],angularVelocity=1.68) ] from yade import qt qt.View() O.run() >What is the result with Law2_ScGeom_FrictPhys_CundallStrack? I checked it and the problem does not get solved by changing to Cundall. >But firstly I would guess the problem is due to the fact "If I remember correctly, the large bodies are not "periodically copied", so the spheres from "next" cells do not interact with the wall." discussed in [2], #4 I think this is the problem! Because it is like the particles pass through the drum wall and does not interact with it! Regards, Roxana Saghafian From: nore...@launchpad.net on behalf of Jan Stránský Sent: Thursday, August 18, 2022 9:20 AM To: Saghafian Larijani, Roxana (UT-ET) Subject: Re: [Question #702751]: periodic boundary in the direction of the length of a rotating drum (cylinder ) Your question #702751 on Yade changed: https://answers.launchpad.net/yade/+question/702751 Status: Open => Needs information Jan Stránský requested more information: > However, I still have a problem. please, provide a MWE as discussed above. > Might it be because I am using (Law2_ScGeom_ViscElCapPhys_Basic()) as it is mentioned in the question 429604? What is the result with Law2_ScGeom_FrictPhys_CundallStrack? But firstly I would guess the problem is due to the fact "If I remember correctly, the large bodies are not "periodically copied", so the spheres from "next" cells do not interact with the wall." discussed in [2], #4 If it is this case or not would be clear with the MWE. Cheers Jan [2] https://answers.launchpad.net/yade/+question/701266 -- To answer this request for more information, you can either reply to this email or enter your reply at the following page: https://answers.launchpad.net/yade/+question/702751 You received this question notification because you asked the 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 #702344]: Permeability of non-spherical (e.g. polyhedral) particles packing
Question #702344 on Yade changed: https://answers.launchpad.net/yade/+question/702344 Soheil Safari 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 #702815]: How to user-defined the shape of particle?
Question #702815 on Yade changed: https://answers.launchpad.net/yade/+question/702815 Status: Open => Needs information Jan Stránský requested more information: Do you have some specific link? I have found [2], but there is no mention of cylinder.. But from the (very) brief scan of [2], do you need actual cylinder? Isn't "transforming into surface contact by equipping the sphere particle with a cylinder geometric model" just a "cylindrical model" of the contact and no true cylinder is needed? Cheers Jan [2] http://docs.itascacg.com/pfc600/common/contactmodel/flatjoint/doc/manual/cmflatjoint.html -- 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 #702815]: How to user-defined the shape of particle?
Question #702815 on Yade changed: https://answers.launchpad.net/yade/+question/702815 Status: Needs information => Open xuanshenyu gave more information on the question: Hi, Jan I am currently studying the particle bonding model, Flat-Joint Contact Model (FJM), proposed by Professor Potyondy in 2013[1]. In FJM, the point contact is transformed into surface contact by equipping the sphere particle with a cylinder geometric model. I want to replicate FJM and add it to Yade. Shenyu [1] Potyondy D (2013) PFC3D flat joint contact model version 1. Itasca Consulting Group. Minneapolis, Technical Memorandum ICG7234-L -- 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 #702743]: Sensitivity testing: Results seem random
Question #702743 on Yade changed: https://answers.launchpad.net/yade/+question/702743 Status: Open => Answered Jan Stránský proposed the following answer: Hello, thanks for the data > 1) All plots have runs that start negative, which is not intuitive. I feel they should all start at zero (or close to it). You push "the object" down through the packing, which also is not vary intuitive.. At the end, you of course has some have some forces and torque on the object. The orientation of the forces and the sense of the torque are basically random (due to just pushing down), possibly negative. > 2) Sometimes results can be radically different (e.g., density_Sensitivity_Testing.png) With this coarse spherical packing w.r.t. the object, I expect significant discrepancy w.r.t. initial particle packing. Not the initial particle packing before the gravity deposition, which seems to be the same using memoizeDb, but the "starting packing" after gravity deposition, which might differ (see below). Check if you have same or different packing after the gravity deposition. > 3) Even when not radically different, the results doesn't make inherit sense. I.e., spheres with less density can create more torque on the object than spheres with a lower density. what is density? Material density? Packing density? If material density, then the packing difference is probably more significant for the results then the material density.. How do you run your simulation? Using parallel / multicore run, or not? If yes, then you intrinsically get different results [1]. Specifically for your case, different "starting packing". Even with same "starting packing", you simply get different results. Cheers Jan [1] https://yade-dem.org/doc/formulation.html#result-indeterminism -- 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 #702750]: How to detect the coordinates of each particle?
Question #702750 on Yade changed: https://answers.launchpad.net/yade/+question/702750 Jan Stránský proposed the following answer: > But how can I strictly define particles as belonging to the top layer, I don't seem to have a train of thought. This is up to you. There are a lot of reasonable approaches how to define it. > My first thought was to use coordinates to define the uppermost particles yes, this is one of the most easiest and straightforward approach, get the highest coordinate zMax and say all particles with z coodinate larger than zMax - someLayerThickness is the layer. Or you can define number of particles in the layer, sort particles w.r.t. z coordinate and define the layer as first N particles. Or you can define "numerical blanket", let it fall to the packing and define touching particles as the top layer. Or It really depends on definition, purposes, available / needed time to use / develop a method, ... > but the coordinates of these particles are also unknown quantities, coordinates of particles are of course known quantities (all this thread is about it). 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 #702815]: How to user-defined the shape of particle?
Question #702815 on Yade changed: https://answers.launchpad.net/yade/+question/702815 Status: Open => Needs information Jan Stránský requested more information: Hello, please define more in detail what is "a shape of particle by shpere and cylinder" (now it is too ambiguous) and how it "can improve the contact among particles." 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 #702751]: periodic boundary in the direction of the length of a rotating drum (cylinder )
Question #702751 on Yade changed: https://answers.launchpad.net/yade/+question/702751 Status: Open => Needs information Jan Stránský requested more information: > However, I still have a problem. please, provide a MWE as discussed above. > Might it be because I am using (Law2_ScGeom_ViscElCapPhys_Basic()) as it is mentioned in the question 429604? What is the result with Law2_ScGeom_FrictPhys_CundallStrack? But firstly I would guess the problem is due to the fact "If I remember correctly, the large bodies are not "periodically copied", so the spheres from "next" cells do not interact with the wall." discussed in [2], #4 If it is this case or not would be clear with the MWE. Cheers Jan [2] https://answers.launchpad.net/yade/+question/701266 -- 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
