An impact simulation got an error

Hello,
next time please put the error message in the question, here it would have
been possible to answer directly without testing the script :-)

O.bodies.append returns id(s) of appended bodies, not bodies themselves. So
just modify the code in the following way:

ball_id = O.bodies.append(...)
ball = O.bodies[ball_id]
...

another point, PWaveTimeStep() returns theoretical critical time step, it
is a good idea to multiply it by 0.8 or 0.5, but there is no need to make
the time ste 1000x smaller..

cheers
Jan

2016-11-16 12:47 GMT+01:00 Huihuang Xia <
<email address hidden>>:

> New question #404127 on Yade:
> https://answers.launchpad.net/yade/+question/404127
>
> Hi,
> I simulated a steel ball impacted on a particle assembly at a high speed,
> but my code got an error, that is the steel ball not move. My codes is as
> follows, please help me to solve this problem. Many thanks!
>
>
> from yade import pack
> ##### define materials for particles and mill #####
> rock=O.materials.append(CohFrictMat(young=5.98e7,poisson=0.3,density=2678,
> frictionAngle=0.5,normalCohesion=1.2e10,shearCohesion=1.2e9,
> momentRotationLaw=True))
> steel=O.materials.append(FrictMat(young=3.06e11,poisson=0.29,density=7861,
> frictionAngle=0.545))
>
> ##### create partciles assembly #####
> pred=pack.inAlignedBox((-0.1,-0.1,-0.1),(0.1,0.1,0.1))
> spheres=pack.randomDensePack(pred,radius=0.005,rRelFuzz=0.
> 3,spheresInCell=1500,material=rock,color=(1,0,1))
> O.bodies.append(spheres)
> ##### create a rigid ball #####
> ball=O.bodies.append(sphere(center=(0,0,0.5),radius=0.1,
> color=(0,1,1),material=steel))
> ball.blockedDOFs='xyXYZ'
> ball.state.vel=Vector3(0,0,-1) ##### set velocity along axis-Z
> O.engines=[
> ForceResetter(),
> InsertionSortCollider([Bo1_Sphere_Aabb(),Bo1_Facet_Aabb()]),
> InteractionLoop(
> [Ig2_Sphere_Sphere_ScGeom6D(interactionDetectionFactor=1.
> 1)],
> [Ip2_FrictMat_FrictMat_FrictPhys(),Ip2_CohFrictMat_
> CohFrictMat_CohFrictPhys(setCohesionNow=True)],
> [Law2_ScGeom_FrictPhys_CundallStrack(),Law2_ScGeom6D_
> CohFrictPhys_CohesionMoment()]
> ),
> NewtonIntegrator(damping=0.3,gravity=(0,0,-9.81))
> ]
>
> from yade import qt
> qt.View()
> qt.Controller()
> #qt.Renderer().shape=0
> #qt.Renderer().intrPhys=1
> O.dt=0.001*PWaveTimeStep()
>
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