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I move this from https://bugs.launchpad.net/yade/+bug/1832235 to https://gitlab.com/yade-dev/trunk/issues/84 ** Bug watch added: gitlab.com/yade-dev/trunk/issues #84 https://gitlab.com/yade-dev/trunk/issues/84 -- You received this bug notification because you are a member of Yade developers, which is subscribed to Yade. https://bugs.launchpad.net/bugs/1832235 Title: The NewtonIntegrator does not apply angular motion for aspherical bodies Status in Yade: New Bug description: I've tried several ways to impose an initial angular velocity on a free polyhedron but they do not work well as commented in the script and below. Please help me with this. Thanks! Here are things I've observed: [In the code below, I simulate 2 polyhedrons, poly1 is free and has an initial velocity while poly2 is fixed.] If I directly use state.angVel or utils.setBodyAngularVelocity to impost an angular velocity on both polyhedrons, nothing happens to poly1, I could observe no rotation but just transnational move. However, I could observe rotation on poly2, which is fixed. A work around is to use angMom. ## using: "b.state.angMom" Mom=b1.state.ori*b1.state.inertia # This results to angVel=Vector3(1,1,1). # Modify accordingly, to modify a specific angular velocity. e.g., to get an initial angVel=Vector3(5,6,7) Mom[0]=Mom[0]*5. Mom[1]=Mom[1]*6. Mom[2]=Mom[2]*7. O.bodies[0].state.angMom=Mom # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # ENGINES # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # O.engines=[ ForceResetter(), InsertionSortCollider([Bo1_Polyhedra_Aabb()],verletDist=0.01), InteractionLoop( [Ig2_Polyhedra_Polyhedra_PolyhedraGeom()], [Ip2_PolyhedraMat_PolyhedraMat_PolyhedraPhys()], [Law2_PolyhedraGeom_PolyhedraPhys_Volumetric()] ), NewtonIntegrator(damping=0.0,exactAsphericalRot=True,gravity=[0,0,0]), ] # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # POLYHEDRAL PARTICLES # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # from yade import polyhedra_utils m = PolyhedraMat() m.density = 2000 #kg/m^3 m.young = 150e6 #Pa m.poisson = .4 m.frictionAngle = 3.0 #rad edge=0.025 vertices=[(-edge, -edge, -edge), (-edge, edge, -edge), ( edge, -edge, -edge), ( edge, edge, -edge), (-edge, -edge, edge), (-edge, edge, edge), ( edge, -edge, edge), ( edge, edge, edge)] # Free b1 = polyhedra_utils.polyhedra(m,v=vertices) b1.state.pos = (0,0,0) O.bodies.append(b1) # Fixed b2 = polyhedra_utils.polyhedra(m,v=vertices,fixed=True) b2.state.pos = (4.*edge,0,0) O.bodies.append(b2) # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # INITIAL VELOCITY # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # Initial translational velocity O.bodies[0].state.vel=Vector3(1,0,0) # Initial angular velocity # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # ##Directly assigning the angular velocity- Not imposing initial angular velocity- No rotation for the free one but the fixed one will rotate #O.bodies[0].state.angVel=Vector3(1,1,0) #O.bodies[1].state.angVel=Vector3(1,1,0) ## using: "utils.setBodyAngularVelocity" - Not working for non-fixed bodies(poly1) but working for poly2 utils.setBodyAngularVelocity(0,5*Vector3(1,1,1)) utils.setBodyAngularVelocity(1,5*Vector3(1,1,1)) # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # from yade import qt v=qt.View() O.dt=1.0e-8 O.saveTmp() To manage notifications about this bug go to: https://bugs.launchpad.net/yade/+bug/1832235/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~yade-dev Post to : yade-dev@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-dev More help : https://help.launchpad.net/ListHelp
