Question #290372 on Yade changed: https://answers.launchpad.net/yade/+question/290372
Status: Open => Answered Jan Stránský proposed the following answer: Hi Mohsen, see the links below. For the same radius R: E = .5*(young1+young2) kn = pi*r^2*E/distance cheers Jan [1] https://yade-dem.org/doc/formulation.html#normal-stiffness [2] http://bazaar.launchpad.net/~yade-pkg/yade/git-trunk/view/head:/pkg/dem/ConcretePM.cpp#L77 [3] http://bazaar.launchpad.net/~yade-pkg/yade/git-trunk/view/head:/pkg/dem/ConcretePM.cpp#L321 2016-04-10 14:52 GMT+02:00 mohsen <question290...@answers.launchpad.net>: > New question #290372 on Yade: > https://answers.launchpad.net/yade/+question/290372 > > In the name of god > hello all > during an script i make contact between two spheres of Cpm material but > the different parameters. There are two bouncing spheres. Then i checked > O.interactions two see the contact parameters. I do not know how the young > modulus of contact has been computed? > any idea? > > Thanks every one > ##### > > mat2=CpmMat(young=1e6,neverDamage=True,density=2500,poisson=0.2,epsCrackOnset=1e20,relDuctility=10,frictionAngle=0.5,label='mat2') > O.materials.append(mat2) > > O.materials.append(CpmMat(young=1e12,neverDamage=True,poisson=0.3,frictionAngle=radians(30),sigmaT=4e100,epsCrackOnset=1e20,density=2600,relDuctility=10,label='mat1')) > > O.bodies.append([ > > sphere(center=(0,0,0),radius=.5,fixed=True, material='mat1'), > > sphere((0,0,2),.5, material='mat2') > ]) > > intRadius = 1 > O.engines = [ > ForceResetter(), > > InsertionSortCollider([Bo1_Sphere_Aabb(aabbEnlargeFactor=intRadius,label='is2aabb'),Bo1_Facet_Aabb(),Bo1_Wall_Aabb()]), > InteractionLoop( > > [Ig2_Sphere_Sphere_ScGeom(interactionDetectionFactor=intRadius,label='ss2d3dg'),Ig2_Facet_Sphere_ScGeom(),Ig2_Wall_Sphere_ScGeom()], > [Ip2_CpmMat_CpmMat_CpmPhys()], > [Law2_ScGeom_CpmPhys_Cpm()] > ), > NewtonIntegrator(gravity=(0,0,-10),damping=0.2), > ] > O.dt = .2*PWaveTimeStep() > ######### > > The interaction specifications: > > {'E': 500000500000.0, > 'G': 175000175000.0, > 'crossSection': 0.7853981633974483, > 'damLaw': 1, > 'dmgOverstress': 0.0, > 'dmgRateExp': 0.0, > 'dmgStrain': 0.0, > 'dmgTau': -1.0, > 'epsCrackOnset': 1e+20, > 'epsFracture': 1e+21, > 'isCohesive': False, > 'isoPrestress': 0.0, > 'kn': 392699474749.80115, > 'ks': 137444816162.43042, > 'neverDamage': True, > 'normalForce': Vector3(0,0,-7853.981599551652), > 'plRateExp': 0.0, > 'plTau': -1.0, > 'refLength': 0.9999999991036522, > 'refPD': 8.963477737822245e-10, > 'relDuctility': 10.0, > 'shearForce': Vector3(-0,-0,-7.623695394542987e-13), > 'tanFrictionAngle': 0.9538822108108043, > 'undamagedCohesion': 2e+100} > > > -- > 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 > -- 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