It can be related to https://bugs.launchpad.net/yade/+bug/577581
______________________________ Anton Gladkyy 2010/5/26 luc scholtes <[email protected]> > Hi Anton, > > Thank you for the link. > > After few tests, it seems that CohesivefrictionalPM does not work in its > actual version (is it related to Eigen?...). More particularly, it seems > that the problem comes from the part related to the moment rotation law (see > the concerned code below). I know that it is a pity to have copy/paste this > code from Bruno's work on CohesivefrictionalContactLaw, but I cannot see > where is the problem (I tried to follow all the wm3->Eigen conversions, and > it seems ok). > > Does anibody have any suggestion? I am stucked... > > Luc > > > /* Moment Rotation Law */ > // NOTE this part could probably be computed in ScGeom to avoid > copy/paste multiplication !!! > Quaternionr delta( b1->state->ori * > phys->initialOrientation1.conjugate() *phys->initialOrientation2 * > b2->state->ori.conjugate()); //relative orientation > AngleAxisr aa(angleAxisFromQuat(delta)); // axis of rotation - this is > the Moment direction UNIT vector; angle represents the power of resistant > ELASTIC moment > if(aa.angle() > Mathr::PI) aa.angle() -= Mathr::TWO_PI; // angle is > between 0 and 2*pi, but should be between -pi and pi > > phys->cumulativeRotation = aa.angle(); > > //Find angle*axis. That's all. But first find angle about contact > normal. Result is scalar. Axis is contact normal. > Real angle_twist(aa.angle() * aa.axis().dot(geom->normal) ); //rotation > about normal > Vector3r axis_twist(angle_twist * geom->normal); > Vector3r moment_twist(axis_twist * phys->kr); > > Vector3r axis_bending(aa.angle()*aa.axis() - axis_twist); //total > rotation minus rotation about normal > Vector3r moment_bending(axis_bending * phys->kr); > Vector3r moment = moment_twist + moment_bending; > > Real MomentMax = phys->maxBend*std::fabs(phys->normalForce.norm()); > Real scalarMoment = moment.norm(); > > /*Plastic moment */ > if(scalarMoment > MomentMax) > { > Real ratio = 0; > ratio *= MomentMax/scalarMoment; // to fix the moment to its yielding > value > moment *= ratio; > moment_twist *= ratio; > moment_bending *= ratio; > } > > phys->moment_twist = moment_twist; > phys->moment_bending = moment_bending; > > rootBody->forces.addTorque(id1,-moment); > rootBody->forces.addTorque(id2, moment); > > or maybe from the > > > 2010/5/26 Anton Gladky <[email protected]> > > Hi, Luc! >> >> Have a look here: >> https://yade-dem.org/wiki/Wm3%E2%86%92Eigen >> >> Eigen is a actively developed mathematical library. Wm3 is, as I know, >> does not develops now. Eigen gives a great functionality through API and >> well-supported. >> ______________________________ >> >> >
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