# yade-users team mailing list archive

## Re: [Question #693690]: problems in making a 2D packing using TriaxialStressController

Chen Lifan posted a new comment:
Hello Jan,

thank you for your detailed instructions. In fact, I solved the problem
by using exactly one of the ways you propose above, i.e. specifying the
wall ids explicitly. For further reference, here are my scripts:

O.materials.append(CohFrictMat(young=88.e9,alphaKr=2.0,alphaKtw=0.,poisson=.7,frictionAngle=.0,isCohesive=True,normalCohesion=3.e9,shearCohesion=3.e9,momentRotationLaw=True,label='rock'))
O.materials.append(FrictMat(young=2e11,poisson=.4,frictionAngle=0,density=0,label='frictionlessWalls'))
sp = pack.SpherePack()
size = .3
sp.makeCloud(minCorner=(0,0,.05),maxCorner=(size,size,.05),rMean=.005,rRelFuzz=0.2,num=400,periodic=False,seed=1)
walls=aabbWalls(thickness=0,material='frictionlessWalls')
wallIds=O.bodies.append(walls)
#O.bodies.erase(wallIds[4])
#O.bodies.erase(wallIds[5])

#O.cell.hSize = Matrix3(size,0,0, 0,size,0, 0,0,.1)
print len(O.bodies)
for i in range(400):
p=O.bodies[i]
p.state.blockedDOFs = 'zXY'
p.state.mass = 2650 * 0.1 * pi * p.shape.radius**2 # 0.1 = thickness of cylindrical particle
inertia = 0.5 * p.state.mass * p.shape.radius**2
p.state.inertia = (.5*inertia,.5*inertia,inertia)

O.dt = .5*utils.PWaveTimeStep()
print O.dt

triax=TriaxialStressController(
wall_bottom_id=wallIds[2],
wall_top_id=wallIds[3],
wall_left_id=wallIds[0],
wall_right_id=wallIds[1],
wall_back_id=wallIds[4],
wall_front_id=wallIds[5],
internalCompaction=False,
stressMask = 3, #1 is x, 2 is y, 4 is z, Bitmask, if imposed goal`s are stresses (0 for none, 7 for all, 1 for direction 1, 5 for directions 1 and 3, etc. :ydefault:`7)
goal1 = -1.e7,
goal2 = -1.e7, # positive is tension, negative is compression
goal3 = 0.,
max_vel=0.01,
label = 'triax'
)

O.engines = [
ForceResetter(),
InsertionSortCollider([Bo1_Sphere_Aabb(),Bo1_Box_Aabb()]),
InteractionLoop(
[Ig2_Sphere_Sphere_ScGeom6D(),Ig2_Box_Sphere_ScGeom()],
[Ip2_FrictMat_FrictMat_FrictPhys(),
Ip2_CohFrictMat_CohFrictMat_CohFrictPhys(
label='cohesiveIp',
setCohesionNow=False)],
[Law2_ScGeom_FrictPhys_CundallStrack(),
Law2_ScGeom6D_CohFrictPhys_CohesionMoment( # contact law
useIncrementalForm=False,
always_use_moment_law=False,
label='cohesiveLaw')]
),
triax,
NewtonIntegrator(damping=.2)
]
O.run(1000,True)

--