New question #686278 on Yade: https://answers.launchpad.net/yade/+question/686278
Hi, In [1], it shows a method to reach isotropic state by using particle growing (internalCompaction=True). However, if we use this method, there will be a scale up from initial (i.e. input) particle size distribution, like Figure 1 in [2]. What I want to achieve is to reach isotropic state without particle growing, something like the PSD curve in Figure 9 in [3]. So I set internalCompaction=False in order to keep constant particle size. The problem is when I set internalCompaction=False, the size of the sample changed. For example, the size of initial packing is 0.7*0.7*1.4 (i.e. mn,mx=Vector3(0,0,0),Vector3(0.7,0.7,1.4)), when I set internalCompaction=True, after compacted state completed, the size of the packing stays around 0.7*0.7*1.4. However, when I set internalCompaction=False, after compacted state completed, the size of the packing is changed to 0.26*0.26*0.9, and in this case, I can not obtain a reasonable sample in terms of size. The following MWE may show this question by changing internalCompaction= True to False. ########### from yade import pack, plot nRead=readParamsFromTable( num_spheres=1000, compFricDegree = 30, key='_triax_base_', unknownOk=True ) from yade.params import table num_spheres=table.num_spheres key=table.key targetPorosity = 0.43 compFricDegree = table.compFricDegree finalFricDegree = 30 rate=-0.02 damp=0.2 stabilityThreshold=0.01 young=5e6 mn,mx=Vector3(0,0,0),Vector3(0.7,0.7,1.4) 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=aabbWalls([mn,mx],thickness=0,material='walls') wallIds=O.bodies.append(walls) sp=pack.SpherePack() sp.makeCloud(mn,mx,-1,0.3333,num_spheres,False, 0.95,seed=1) O.bodies.append([sphere(center,rad,material='spheres') for center,rad in sp]) Gl1_Sphere.quality=3 ### DEFINING ENGINES ### triax=TriaxialStressController( maxMultiplier=1.+2e4/young, finalMaxMultiplier=1.+2e3/young, thickness = 0, stressMask = 7, internalCompaction=True,## please change True to False here to look at what I say ) newton=NewtonIntegrator(damping=damp) O.engines=[ ForceResetter(), InsertionSortCollider([Bo1_Sphere_Aabb(),Bo1_Box_Aabb()]), InteractionLoop( [Ig2_Sphere_Sphere_ScGeom(),Ig2_Box_Sphere_ScGeom()], [Ip2_FrictMat_FrictMat_FrictPhys()], [Law2_ScGeom_FrictPhys_CundallStrack()] ), GlobalStiffnessTimeStepper(active=1,timeStepUpdateInterval=100,timestepSafetyCoefficient=0.8), triax, newton ] Gl1_Sphere.stripes=0 if nRead==0: yade.qt.Controller(), yade.qt.View() ### APPLYING CONFINING PRESSURE ### triax.goal1=triax.goal2=triax.goal3=-10000 while 1: O.run(1000, True) unb=unbalancedForce() print 'unbalanced force:',unb,' mean stress: ',triax.meanStress if unb<stabilityThreshold and abs(-10000-triax.meanStress)/10000<0.001: break print "### Isotropic state saved ###" ### REACHING A SPECIFIED POROSITY PRECISELY ### import sys while triax.porosity>targetPorosity: # we decrease friction value and apply it to all the bodies and contacts compFricDegree = 0.95*compFricDegree setContactFriction(radians(compFricDegree)) print "\r Friction: ",compFricDegree," porosity:",triax.porosity, sys.stdout.flush() O.run(500,1) print "### Compacted state saved ###" ######################## Could you please give some instructions? Thanks, Leonard [1]https://github.com/yade/trunk/blob/master/examples/triax-tutorial/script-session2.py [2]https://link.springer.com/article/10.1007/s11440-017-0593-6 [3]https://link.springer.com/article/10.1007%2Fs10035-016-0687-0 -- 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
