Question #688060 on Yade changed: https://answers.launchpad.net/yade/+question/688060
Status: Needs information => Open ehsan benabbas gave more information on the question: Hi Jan, Thanks for your helps This is the code: from yade import pack ############################################ ### DEFINING VARIABLES AND MATERIALS ### ############################################ # The following 5 lines will be used later for batch execution nRead=readParamsFromTable( num_spheres=1000,# number of spheres compFricDegree = 30, # contact friction during the confining phase key='_triax_base_', # put you simulation's name here unknownOk=True ) from yade.params import table num_spheres=table.num_spheres# number of spheres key=table.key targetPorosity = 0.43 #the porosity we want for the packing compFricDegree = table.compFricDegree # initial contact friction during the confining phase (will be decreased during the REFD compaction process) finalFricDegree = 30 # contact friction during the deviatoric loading rate=-0.02 # loading rate (strain rate) damp=0.2 # damping coefficient stabilityThreshold=0.01 # we test unbalancedForce against this value in different loops (see below) young=5e6 # contact stiffness mn,mx=Vector3(0,0,0),Vector3(1,1,1) # corners of the initial packing ## create materials for spheres and plates 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')) ## create walls around the packing walls=aabbWalls([mn,mx],thickness=0,material='walls') wallIds=O.bodies.append(walls) ## use a SpherePack object to generate a random loose particles packing sp=pack.SpherePack() clumps=False #turn this true for the same example with clumps if clumps: ## approximate mean rad of the futur dense packing for latter use volume = (mx[0]-mn[0])*(mx[1]-mn[1])*(mx[2]-mn[2]) mean_rad = pow(0.09*volume/num_spheres,0.3333) ## define a unique clump type (we could have many, see clumpCloud documentation) c1=pack.SpherePack([((-0.2*mean_rad,0,0),0.5*mean_rad),((0.2*mean_rad,0,0),0.5*mean_rad)]) ## generate positions and input them in the simulation sp.makeClumpCloud(mn,mx,[c1],periodic=False) sp.toSimulation(material='spheres') O.bodies.updateClumpProperties()#get more accurate clump masses/volumes/inertia else: sp.makeCloud(mn,mx,-1,0.3333,num_spheres,False, 0.95,seed=1) #"seed" make the "random" generation always the same O.bodies.append([sphere(center,rad,material='spheres') for center,rad in sp]) #or alternatively (higher level function doing exactly the same): #sp.toSimulation(material='spheres') ############################ ### DEFINING ENGINES ### ############################ triax=TriaxialStressController( ## TriaxialStressController will be used to control stress and strain. It controls particles size and plates positions. ## this control of boundary conditions was used for instance in http://dx.doi.org/10.1016/j.ijengsci.2008.07.002 maxMultiplier=1.+2e4/young, # spheres growing factor (fast growth) finalMaxMultiplier=1.+2e3/young, # spheres growing factor (slow growth) thickness = 0, ## switch stress/strain control using a bitmask. What is a bitmask, huh?! ## Say x=1 if stess is controlled on x, else x=0. Same for for y and z, which are 1 or 0. ## Then an integer uniquely defining the combination of all these tests is: mask = x*1 + y*2 + z*4 ## to put it differently, the mask is the integer whose binary representation is xyz, i.e. ## "100" (1) means "x", "110" (3) means "x and y", "111" (7) means "x and y and z", etc. stressMask = 7, internalCompaction=True, # If true the confining pressure is generated by growing particles ) 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()] ), ## We will use the global stiffness of each body to determine an optimal timestep (see https://yade-dem.org/w/images/1/1b/Chareyre&Villard2005_licensed.pdf) GlobalStiffnessTimeStepper(active=1,timeStepUpdateInterval=100,timestepSafetyCoefficient=0.8), triax, TriaxialStateRecorder(iterPeriod=100,file='WallStresses'+table.key), newton ] #Display spheres with 2 colors for seeing rotations better Gl1_Sphere.stripes=0 if nRead==0: yade.qt.Controller(), yade.qt.View() ## UNCOMMENT THE FOLLOWING SECTIONS ONE BY ONE ## DEPENDING ON YOUR EDITOR, IT COULD BE DONE ## BY SELECTING THE CODE BLOCKS BETWEEN THE SUBTITLES ## AND PRESSING CTRL+SHIFT+D ####################################### ### APPLYING CONFINING PRESSURE ### ####################################### #the value of (isotropic) confining stress defines the target stress to be applied in all three directions triax.goal1=triax.goal2=triax.goal3=-10000 #while 1: #O.run(1000, True) ##the global unbalanced force on dynamic bodies, thus excluding boundaries, which are not at equilibrium #unb=unbalancedForce() #print 'unbalanced force:',unb,' mean stress: ',triax.meanStress #if unb<stabilityThreshold and abs(-10000-triax.meanStress)/10000<0.001: #break #O.save('confinedState'+key+'.yade.gz') #print "### Isotropic state saved ###" ################################################### ### REACHING A SPECIFIED POROSITY PRECISELY ### ################################################### ## We will reach a prescribed value of porosity with the REFD algorithm ## (see http://dx.doi.org/10.2516/ogst/2012032 and ## http://www.geosyntheticssociety.org/Resources/Archive/GI/src/V9I2/GI-V9-N2-Paper1.pdf) import sys #this is only for the flush() below 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() # while we run steps, triax will tend to grow particles as the packing # keeps shrinking as a consequence of decreasing friction. Consequently # porosity will decrease O.run(500,1) O.save('compactedState'+key+'.yade.gz') print ("### Compacted state saved ###") ############################## ### DEVIATORIC LOADING ### ############################## #We move to deviatoric loading, let us turn internal compaction off to keep particles sizes constant triax.internalCompaction=False # Change contact friction (remember that decreasing it would generate instantaneous instabilities) setContactFriction(radians(finalFricDegree)) #set stress control on x and z, we will impose strain rate on y triax.stressMask = 5 #now goal2 is the target strain rate triax.goal2=rate # we define the lateral stresses during the test, here the same 10kPa as for the initial confinement. triax.goal1=-10000 triax.goal3=-10000 #we can change damping here. What is the effect in your opinion? newton.damping=0.1 #Save temporary state in live memory. This state will be reloaded from the interface with the "reload" button. O.saveTmp() ##################################################### ### Example of how to record and plot data ### ##################################################### from yade import plot ## a function saving variables def history(): plot.addData(e11=-triax.strain[0], e22=-triax.strain[1], e33=-triax.strain[2], ev=-triax.strain[0]-triax.strain[1]-triax.strain[2], s11=-triax.stress(triax.wall_right_id)[0], s22=-triax.stress(triax.wall_top_id)[1], s33=-triax.stress(triax.wall_front_id)[2], i=O.iter) if 1: # include a periodic engine calling that function in the simulation loop O.engines=O.engines[0:5]+[PyRunner(iterPeriod=20,command='history()',label='recorder')]+O.engines[5:7] #O.engines.insert(4,PyRunner(iterPeriod=20,command='history()',label='recorder')) else: # With the line above, we are recording some variables twice. We could in fact replace the previous # TriaxialRecorder # by our periodic engine. Uncomment the following line: O.engines[4]=PyRunner(iterPeriod=20,command='history()',label='recorder') O.run(100,True) ## declare what is to plot. "None" is for separating y and y2 axis #plot.plots={'i':('e11','e22','e33',None,'s11','s22','s33')} ## the traditional triaxial curves would be more like this: plot.plots={'e22':('s11','s22','s33',None,'ev')} # display on the screen (doesn't work on VMware image it seems) plot.plot() #### PLAY THE SIMULATION HERE WITH "PLAY" BUTTON OR WITH THE COMMAND O.run(N) ##### # In that case we can still save the data to a text file at the the end of the simulation, with: plot.saveDataTxt('results'+key) #or even generate a script for gnuplot. Open another terminal and type "gnuplot plotScriptKEY.gnuplot: plot.saveGnuplot('plotScript'+key) data = [] for i in O.interactions: fn = i.phys.normalForce fs = i.phys.shearForce cp = i.geom.contactPoint normal = i.geom.normal b1,b2 = [O.bodies[id] for id in (i.id1,i.id2)] p1,p2 = [b.state.pos for b in (b1,b2)] branch = p2 - p1 cp,normal,branch,fn,fs = [tuple(v) for v in (cp,normal,branch,fn,fs)] # Vector3 -> tuple d = dict(cp=cp,normal=normal,branch=branch,fn=fn,fs=fs) # new data contains the information, you can save it e.g. as JSON import json with open("interactions.json","w") as f: json.dump(data,f) -- 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 : yade-users@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp