Question #675879 on Yade changed: https://answers.launchpad.net/yade/+question/675879
Robert Caulk posted a new comment: Thank you for putting together a nice MWE showcasing this problem. I looked into your MWE and I believe you found a bug. I am sharing a more dramatic (and concise) MWE below for others who wish to look into this. In this example, setting eps_pos of 1e-5 results in the sphere interacting with the polyhedra. Then, simply changing eps_pos to 0 results in the sphere passing through the polyhedron. I will spend some more time sifting through the source code to identify the bug. I suspect it is somewhere in the collision identification [1]. I will let you know if I find anything, otherwise, we might need one of Yade's polyhedra specialists to look at this. #-------------------- from yade import pack,polyhedra_utils import shutil, sys, imp import numpy as np #------------------- System definition ---------------------- rad_p = 0.1 Xl = 0. Yl = 0. Xr = 1. Yr = 1. Zl = rad_p Zr = 1. eps_pos = 1e-5 #-------------------------- polyMat = PolyhedraMat(young=1e10,poisson=.05) frictMat = FrictMat(young=1e9,poisson=.2) O.materials.append((polyMat,frictMat)) O.bodies.append([sphere((0.5*(Xl+Xr)+eps_pos,0.5*(Yl+Yr),-rad_p),rad_p, dynamic=True,material=frictMat) ]) # Sphere object O.bodies.append(polyhedron([(Xl,Yl,Zl),(Xr,Yl,Zl),(Xl,Yr,Zl),(Xr,Yr,Zl),(Xl,Yl,Zr),(Xr,Yl,Zr),(Xl,Yr,Zr),(Xr,Yr,Zr)],wire=False,dynamic=True,material=polyMat)) # polyhedron which compresses the sphere #------------------------------------ O.engines=[ ForceResetter(), InsertionSortCollider([Bo1_Sphere_Aabb(), Bo1_Polyhedra_Aabb()]), InteractionLoop( [Ig2_Sphere_Polyhedra_ScGeom()], [Ip2_FrictMat_PolyhedraMat_FrictPhys()], [Law2_ScGeom_FrictPhys_CundallStrack()], ), #PyRunner(command = 'load()', iterPeriod = 1, label = "checker"), NewtonIntegrator() ] O.bodies[1].state.blockedDOFs = 'xyzXYZ' O.bodies[0].state.vel = Vector3(0,0,1e-1) #--------------------------- O.dt=.5*PWaveTimeStep() O.step() #------------------- [1]https://github.com/yade/trunk/blob/master/pkg/dem/Polyhedra_Ig2.cpp#L342 -- 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
