Question #201769 on Yade changed: https://answers.launchpad.net/yade/+question/201769
Chiara Modenese proposed the following answer: Hi Anna, Are you aware that you input in the model some rolling resistance (if you try with the bool includeMoment=False you will see what I mean)? I think that explains the behaviour. Can you please try to explain here the purpose of your test? It may help us to give you a better answer. Thank you, Chiara On 29 Jun 2012, at 07:01, anna effeindzourou wrote: > New question #201769 on Yade: > https://answers.launchpad.net/yade/+question/201769 > > Hi all, > I am using the Hertz Mindlin contact law with a simple example a sphere > rolling on a inclined facet and then on a horizontal facet. I've observed > that the sphere is rolling up and down. > Here is a small script to help you understand the phenomenon. > > > #!/usr/bin/python > # -*- coding: utf-8 -*- > from yade import utils > > h=0.2 > > O.materials.append(FrictMat(young=1.7e8,poisson=0.20588,frictionAngle=radians(17),density=2650)) > s1=O.bodies.append( > utils.sphere([0.0000001,0.5,h+0.1],.1,color=[0,1,0],fixed=False,wire=True)) > > > v1=(0,0,h) > v6=(0,1,h) > v2=(.5,0,0) > v3=(2,0,0) > > v4=(2,1,0) > v5=(0.5,1,0) > > f1=O.bodies.append( utils.facet([v1,v2,v5], dynamic=None, fixed=True, > wire=True, color=None, highlight=False, noBound=False, mask=1)) > f2=O.bodies.append( utils.facet([v1,v5,v6], dynamic=None, fixed=True, > wire=True, color=None, highlight=False, noBound=False, mask=1)) > f3=O.bodies.append( utils.facet([v2,v3,v4], dynamic=None, fixed=True, > wire=True, color=None, highlight=False, noBound=False, mask=1)) > f4=O.bodies.append( utils.facet([v2,v4,v5], dynamic=None, fixed=True, > wire=True, color=None, highlight=False, noBound=False, mask=1)) > > ## time step > O.dt=1e-5 > > O.engines=[ > ForceResetter(), > InsertionSortCollider([Bo1_Sphere_Aabb(),Bo1_Facet_Aabb()]), > InteractionLoop( > [Ig2_Facet_Sphere_ScGeom(),Ig2_Sphere_Sphere_ScGeom()], > [ > Ip2_FrictMat_FrictMat_MindlinPhys(en=0.1, krot=1,eta=1) > ], > [Law2_ScGeom_MindlinPhys_Mindlin(includeMoment=True), > ]), > NewtonIntegrator(damping=0,gravity=(0,0,-9.81)), > ] > > Any ideas? > > cheers, > Anna > > -- > You received this question notification because you are a member of > yade-users, which is an answer contact for Yade. > > _______________________________________________ > Mailing list: https://launchpad.net/~yade-users > Post to : [email protected] > Unsubscribe : https://launchpad.net/~yade-users > More help : https://help.launchpad.net/ListHelp -- You received this question notification because you are a member of yade-users, which is an answer contact for Yade. _______________________________________________ Mailing list: https://launchpad.net/~yade-users Post to : [email protected] Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
