[Yade-users] [Question #700475]: interface friction angle
New question #700475 on Yade: https://answers.launchpad.net/yade/+question/700475 Hi All, I hope you are doing well. Recently, I am doing a cone penetration simulation. the following is part of the code. ## from yade import ymport import itertools from numpy import * import numpy as np from yade import pack, plot, export, utils,geom import math target=0.12 young=4e8 finalcompFricDegree=19.5 frictDegree = 39.5 # sphere particles material properties sphereMat=O.materials.append(CohFrictMat(young=young,poisson=0.3,frictionAngle=radians(finalcompFricDegree),isCohesive=False,alphaKr=0.2,alphaKtw=0,etaRoll=0.5,momentRotationLaw=True,density=2648)) O.bodies.append(ymport.text("rotation-loose-sample-Dr-03.txt",material = sphereMat)) create the penetrator and shaft and the cylinder ## facetMat=O.materials.append(FrictMat(young=young,poisson=0.3,frictionAngle=radians(frictDegree),density=0)) O.materials.append(FrictMat(young=young,poisson=0.3,frictionAngle=0,density=0,label='walls')) facets = O.bodies.append(geom.facetCylinder((200e-3,200e-3,300e-3),200e-3,600e-3,wallMask=6,material='walls',segmentsNumber=100)) ### coloring # cone and shaft geometry parameter ### x0=0.2;y0=0.2;z0=0.39665 cylinderIDS= O.bodies.append(geom.facetCylinder((x0,y0,0.416651), radius=0.0125,height=0.15,orientation=Quaternion((1, 0, 0), 0),wallMask=5,segmentsNumber=10, angleRange=None,material=facetMat)) coneIDS= O.bodies.append(geom.facetCone((x0,y0,0.3308255), radiusTop=0.0125,radiusBottom=0.0,height=0.021651,orientation=Quaternion((1, 0, 0), 0),wallMask=6,segmentsNumber=10, angleRange=None,material=facetMat)) conecheck=O.bodies[-1].id cone and shaft geometry parameter ### ## set the global engine for the simulation O.engines=[ ForceResetter(), InsertionSortCollider([Bo1_Sphere_Aabb(),Bo1_Facet_Aabb()]), InteractionLoop( [Ig2_Sphere_Sphere_ScGeom6D(),Ig2_Facet_Sphere_ScGeom()], [Ip2_FrictMat_FrictMat_FrictPhys(),Ip2_CohFrictMat_CohFrictMat_CohFrictPhys()], [Law2_ScGeom_FrictPhys_CundallStrack(),Law2_ScGeom6D_CohFrictPhys_CohesionMoment(useIncrementalForm=True,always_use_moment_law=True,label='cohesiveLaw')] ), GlobalStiffnessTimeStepper(active=1,timeStepUpdateInterval=10,timestepSafetyCoefficient=0.8), NewtonIntegrator(gravity=(0,0,-9.81),damping=0.0)] # # Generally speaking, the friction angle for particles is 19.5 degrees, while the friction angle for the penetrator (cylindyer+cone) is 39.5 degrees. I also set the friction angle for the penetrator as 29.5 degrees. (I just changed the friction angle for the penetrator, the friction angle for the particle remains the same. ) when I compare the penetration resistance on the cone for the 29.5-degree case and the 39.5-degree case. the penetration resistance on the cone is exactly the same. ### my question is: how does Yade choose the interface friction angle between the interactions when the friction angles were not the same for the particles and the penetrator? best, Yong -- 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 #700475]: interface friction angle
Question #700475 on Yade changed: https://answers.launchpad.net/yade/+question/700475 Status: Open => Answered Luc Scholtès proposed the following answer: Hello, I think the rule for the contact laws you are using is: contact friction angle = min (friction angle body1, friction angle body2) In your case, the cone/particle contact friction angle is thus always equal to 19.5 degrees (particle friction angle) if I understood correctly. Unfortunately, I don't know any "python workaround" to change this rule. From my knowledge, only a change in the C++ code would allow you to have a different behavior. To be confirmed... Luc -- 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 #700475]: interface friction angle
Question #700475 on Yade changed: https://answers.launchpad.net/yade/+question/700475 Jan Stránský proposed the following answer: Hello, The combination of material parameters into interaction parameters is usually done inside Ip2. In your code specifically Ip2_FrictMat_FrictMat_FrictPhys, Ip2_CohFrictMat_CohFrictMat_CohFrictPhys. The resulting interaction value is in both cases documented ([1,2]) as given MatchMaker, or minimum value by default. You can also see source code [3,4]. In your case, minimum value is in both cases 19.5 deg. So your results corresponds to the implementation choice. Cheers Jan [1] https://yade-dem.org/doc/yade.wrapper.html#yade.wrapper.Ip2_FrictMat_FrictMat_FrictPhys.frictAngle [2] https://yade-dem.org/doc/yade.wrapper.html#yade.wrapper.Ip2_CohFrictMat_CohFrictMat_CohFrictPhys.frictAngle [3] https://gitlab.com/yade-dev/trunk/-/blob/master/pkg/dem/FrictPhys.cpp#L39 [4] https://gitlab.com/yade-dev/trunk/-/blob/master/pkg/dem/CohesiveFrictionalContactLaw.cpp#L289 -- 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 #700475]: interface friction angle
Question #700475 on Yade changed: https://answers.launchpad.net/yade/+question/700475 Status: Answered => Solved ytang confirmed that the question is solved: Hi Luc and Jan, Thank you very much! I'm not trying to change the source code right now. I just want to double-check the reason for this question. best, Yong -- 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 #700475]: interface friction angle
Question #700475 on Yade changed: https://answers.launchpad.net/yade/+question/700475 ytang confirmed that the question is solved: Thanks Jan Stránský, 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