[Yade-users] [Question #212480]: Spheres go outside box
New question #212480 on Yade: https://answers.launchpad.net/yade/+question/212480 Hi, I have encountered something strange when conducting gravity deposition: some particles will go outside the box. Can you give some suggestions for solving this problem? Thanks. Nait My script is as following: SCRIPT from yade import pack rm = 0.8 rr = 0.6 compFricDegree = 30 finalFricDegree = 30 stabilityThreshold=0.01 young=5e6 mn,mx=Vector3(0,0,0),Vector3(20,80,200) mxp = Vector3(20,80,150) mnp = Vector3(20,80,90) thick = 0.01 targetporosity = 0.5 O.materials.append(FrictMat(young=young,poisson=0.5,frictionAngle=radians(compFricDegree),density=2600,label='spheres')) O.materials.append(FrictMat(young=young,poisson=0.5,frictionAngle=0,density=0,label='walls')) walls=utils.aabbWalls([mn,mx],thickness=thick,material='walls') wallIds=O.bodies.append(walls) sp=pack.SpherePack() sp.makeCloud(mn,mxp,rMean=rm,rRelFuzz=rr,porosity=targetporosity) O.bodies.append([utils.sphere(center,rad,material='spheres') for center,rad in sp]) O.dt=.5*utils.PWaveTimeStep() # initial timestep, to not explode right away O.usesTimeStepper=True O.engines=[ ForceResetter(), InsertionSortCollider([Bo1_Sphere_Aabb(),Bo1_Box_Aabb()]), InteractionLoop( # handle sphere+sphere and facet+sphere collisions [Ig2_Sphere_Sphere_ScGeom(),Ig2_Box_Sphere_ScGeom()], [Ip2_FrictMat_FrictMat_FrictPhys()], [Law2_ScGeom_FrictPhys_CundallStrack()] ), GravityEngine(gravity=(0,0,-9.81)), NewtonIntegrator(damping=0.6), ] O.run(2000, True) while 1: O.run(500, True) unb=unbalancedForce() print 'unbalanced force:',unb if unb0.01: break yade.qt.Controller(), yade.qt.View() END OF SCRIPT -- 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 : yade-users@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
Re: [Yade-users] [Question #212480]: Spheres go outside box
Question #212480 on Yade changed: https://answers.launchpad.net/yade/+question/212480 Status: Open = Answered Jan Stránský proposed the following answer: Hi Nait, One solution could be to decrease time step. Your material has very low stiffness, so the time step computed from stiffness is too high to represent correctly the collision time step between spheres and box. Or increase your stiffness (maybe this is even better). Let us know if this was the issue :-) Good luck Jan Dne 27.10.2012 12:16 Nait question212...@answers.launchpad.net napsal(a): New question #212480 on Yade: https://answers.launchpad.net/yade/+question/212480 Hi, I have encountered something strange when conducting gravity deposition: some particles will go outside the box. Can you give some suggestions for solving this problem? Thanks. Nait My script is as following: SCRIPT from yade import pack rm = 0.8 rr = 0.6 compFricDegree = 30 finalFricDegree = 30 stabilityThreshold=0.01 young=5e6 mn,mx=Vector3(0,0,0),Vector3(20,80,200) mxp = Vector3(20,80,150) mnp = Vector3(20,80,90) thick = 0.01 targetporosity = 0.5 O.materials.append(FrictMat(young=young,poisson=0.5,frictionAngle=radians(compFricDegree),density=2600,label='spheres')) O.materials.append(FrictMat(young=young,poisson=0.5,frictionAngle=0,density=0,label='walls')) walls=utils.aabbWalls([mn,mx],thickness=thick,material='walls') wallIds=O.bodies.append(walls) sp=pack.SpherePack() sp.makeCloud(mn,mxp,rMean=rm,rRelFuzz=rr,porosity=targetporosity) O.bodies.append([utils.sphere(center,rad,material='spheres') for center,rad in sp]) O.dt=.5*utils.PWaveTimeStep() # initial timestep, to not explode right away O.usesTimeStepper=True O.engines=[ ForceResetter(), InsertionSortCollider([Bo1_Sphere_Aabb(),Bo1_Box_Aabb()]), InteractionLoop( # handle sphere+sphere and facet+sphere collisions [Ig2_Sphere_Sphere_ScGeom(),Ig2_Box_Sphere_ScGeom()], [Ip2_FrictMat_FrictMat_FrictPhys()], [Law2_ScGeom_FrictPhys_CundallStrack()] ), GravityEngine(gravity=(0,0,-9.81)), NewtonIntegrator(damping=0.6), ] O.run(2000, True) while 1: O.run(500, True) unb=unbalancedForce() print 'unbalanced force:',unb if unb0.01: break yade.qt.Controller(), yade.qt.View() END OF SCRIPT -- 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 : yade-users@lists.launchpad.net 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 : yade-users@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
Re: [Yade-users] [Question #212480]: Spheres go outside box
Question #212480 on Yade changed: https://answers.launchpad.net/yade/+question/212480 Nait posted a new comment: To Jan, This is really the issue. The problem is solved when I change the Young's modulus to 20e9. Thank you again for solving my problem. Nait -- 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 : yade-users@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
Re: [Yade-users] [Question #212480]: Spheres go outside box
Question #212480 on Yade changed: https://answers.launchpad.net/yade/+question/212480 Status: Answered = Solved Nait confirmed that the question is solved: Thanks Jan Stránský, that solved my question. -- 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 : yade-users@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
