Question #295587 on Yade changed: https://answers.launchpad.net/yade/+question/295587
Jan Stránský proposed the following answer: Hi Luis, even if you set fixed=False, the facets have by default zero mass and inertia, which causes NaNs in NewtonIntegrator (a=F/m) and particle's positions and they disappear. There are several options: 1) set manually mass and inertia (but then each facet would behave like independent particle, which is probably not what you want) 2) use facet box as a clump (assign mass and inertia to facets before O.bodies.appendClumped) 3) use one Box instead of several facets personally I vote for 3 cheers Jan 2016-06-23 3:57 GMT+02:00 Luis Barbosa <[email protected] >: > New question #295587 on Yade: > https://answers.launchpad.net/yade/+question/295587 > > Hello everyone, > > Consider a box (made using facetbox, facet, .stl...). > The box is created between 2 fixed spheres (one in each side) outside the > box. > The box is free to move horizontally (limited by the spheres). > A step of force is given to the box, which starts to oscillate between the > 2 spheres. > > That is the system I'm trying to analyse, but when I use facet > (fixed=False) the box simply disappears. > Does anybody have some idea? > > Follows the code: > > #!/usr/bin/python > # -*- coding: utf-8 -*- > > # Spheres > > O.materials.append(CohFrictMat(young=15e8,poisson=0.3,density=1000,frictionAngle=radians(30),label='spheres')) > O.bodies.append([ > > utils.sphere(center=(0.5,0.5,0.5),radius=0.1,material='spheres',fixed=False), > > utils.sphere(center=(0.5,0.2,0.2),radius=0.1,material='spheres',fixed=False), > > utils.sphere(center=(0.5,-0.5,0.5),radius=0.3,material='spheres',fixed=True), > utils.sphere(center=(0.5,1.5,0.5),radius=0.3,material='spheres',fixed=True) > ]) > > > ######################################################################################## > O.bodies.append([ > facet([[0,0,0],[1,0,0],[0,1,0]],fixed=False,color=[1,0,0]), > facet([[1,0,0],[1,1,0],[0,1,0]],fixed=False), > facet([[0,0,0],[0,0,1],[0,1,0]],fixed=False), > facet([[0,0,1],[0,1,0],[0,1,1]],fixed=False), > facet([[0,0,1],[1,0,1],[0,1,1]],fixed=False), > facet([[1,1,1],[1,0,1],[0,1,1]],fixed=False), > facet([[1,1,1],[1,0,1],[1,0,0]],fixed=False), > facet([[1,1,1],[1,1,0],[1,0,0]],fixed=False), > facet([[0,0,0],[1,0,0],[0,0,1]],fixed=False), > facet([[0,0,1],[1,0,0],[1,0,1]],fixed=False), > facet([[0,1,0],[1,1,0],[0,1,1]],fixed=False), > facet([[0,1,1],[1,1,0],[1,1,1]],fixed=False) > ]) > > O.engines=[ > ForceResetter(), > InsertionSortCollider([Bo1_Sphere_Aabb(),Bo1_Facet_Aabb()]), > InteractionLoop( > [Ig2_Sphere_Sphere_ScGeom(),Ig2_Facet_Sphere_ScGeom()], > [Ip2_FrictMat_FrictMat_FrictPhys()], > [Law2_ScGeom_FrictPhys_CundallStrack()] > ), > > NewtonIntegrator(damping=0.1,gravity=[0,0,-9.81]), > > ] > O.dt=1e-3*utils.PWaveTimeStep() > > from yade import qt > qt.View() > qt.Controller() > > Thanks, > Luis > > > > -- > 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 : [email protected] > Unsubscribe : https://launchpad.net/~yade-users > More help : https://help.launchpad.net/ListHelp > -- 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 : [email protected] Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
