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#include "LudingPM.hpp"
#include <core/Omega.hpp>
#include <core/Scene.hpp>
#include <core/State.hpp>
#include <pkg/common/Sphere.hpp>
#include <pkg/dem/ScGeom.hpp>
namespace yade { // Cannot have #include directive inside.
YADE_PLUGIN((LudingMat)(LudingPhys)(Ip2_LudingMat_LudingMat_LudingPhys)(Law2_ScGeom_LudingPhys_Basic));
LudingMat::~LudingMat() { }
LudingPhys::~LudingPhys() { }
void Ip2_LudingMat_LudingMat_LudingPhys::go(const shared_ptr<Material>& b1, const shared_ptr<Material>& b2, const shared_ptr<Interaction>& interaction)
{
if (interaction->phys) return;
LudingMat* mat1 = static_cast<LudingMat*>(b1.get());
LudingMat* mat2 = static_cast<LudingMat*>(b2.get());
const Real k11 = mat1->k1;
const Real k12 = mat2->k1;
const Real kp1 = mat1->kp;
const Real kp2 = mat2->kp;
const Real kc1 = mat1->kc;
const Real kc2 = mat2->kc;
const Real ks1 = mat1->ks;
const Real ks2 = mat2->ks;
const Real G01 = mat1->G0;
const Real G02 = mat2->G0;
const Real PhiF1 = mat1->PhiF;
const Real PhiF2 = mat2->PhiF;
LudingPhys* phys = new LudingPhys();
phys->k1 = this->reduced(k11, k12);
phys->kp = this->reduced(kp1, kp2);
phys->kc = this->reduced(kc1, kc2);
phys->ks = this->reduced(ks1, ks2);
phys->PhiF = this->reduced(PhiF1, PhiF2);
phys->k2 = 0.0;
phys->G0 = this->reduced(G01, G02);
Real a1 = 0.0;
Real a2 = 0.0;
Sphere* s1 = dynamic_cast<Sphere*>(Body::byId(interaction->getId1())->shape.get());
Sphere* s2 = dynamic_cast<Sphere*>(Body::byId(interaction->getId2())->shape.get());
Real a1dR = 0.;
Real a2dR = 0.;
#ifdef YADE_DEFORM
State* de1 = dynamic_cast<State*>(Body::byId(interaction->getId1())->state.get());
State* de2 = dynamic_cast<State*>(Body::byId(interaction->getId2())->state.get());
if (de1 and de2) {
a1dR = de1->dR;
a2dR = de2->dR;
} else if (de1 and not(de2)) {
a1dR = de1->dR;
} else {
a2dR = de2->dR;
}
#endif
if (s1 and s2) {
a1 = s1->radius + a1dR;
a2 = s2->radius + a2dR;
} else if (s1 and not(s2)) {
a1 = s1->radius + a1dR;
} else {
a2 = s2->radius + a2dR;
}
if (phys->k1 >= phys->kp) {
throw runtime_error("k1 have to be less as kp!"); // [Luding2008], sentence after equation (6); kp = k2^
// [Singh2013], sentence after equation (6)
}
phys->tangensOfFrictionAngle = math::tan(math::min(mat1->frictionAngle, mat2->frictionAngle));
phys->shearForce = Vector3r(0, 0, 0);
phys->DeltMax = 0.0;
phys->DeltNull = 0.0;
phys->DeltPMax = phys->kp / (phys->kp - phys->k1) * phys->PhiF * 2 * a1 * a2 / (a1 + a2); // [Luding2008], equation (7)
// [Singh2013], equation (11)
phys->DeltPNull = phys->PhiF * 2 * a1 * a2 / (a1 + a2); // [Singh2013], equation (12)
phys->DeltPrev = 0.0;
phys->DeltMin = 0.0;
interaction->phys = shared_ptr<LudingPhys>(phys);
}
Real Ip2_LudingMat_LudingMat_LudingPhys::reduced(Real a1, Real a2)
{
Real a = (a1 ? 1 / a1 : 0) + (a2 ? 1 / a2 : 0);
a = a ? 1 / a : 0;
return 2.0 * a;
}
bool Law2_ScGeom_LudingPhys_Basic::go(shared_ptr<IGeom>& _geom, shared_ptr<IPhys>& _phys, Interaction* I)
{
const ScGeom& geom = *static_cast<ScGeom*>(_geom.get());
LudingPhys& phys = *static_cast<LudingPhys*>(_phys.get());
const int id1 = I->getId1();
const int id2 = I->getId2();
const BodyContainer& bodies = *scene->bodies;
const State& de1 = *static_cast<State*>(bodies[id1]->state.get());
const State& de2 = *static_cast<State*>(bodies[id2]->state.get());
Real addDR = 0.;
#ifdef YADE_DEFORM
addDR = de1.dR + de2.dR;
#endif
const Real Delt = geom.penetrationDepth + addDR;
if (Delt < 0) return false;
Real forceHys = 0.0;
if (phys.DeltMax / phys.DeltPMax >= 1.0) { // [Luding2008], equation (8)
phys.k2 = phys.kp; // [Singh2013], equation (10)
} else {
phys.k2 = phys.k1 + (phys.kp - phys.k1) * phys.DeltMax / phys.DeltPMax;
}
if (phys.k2 > phys.kp) { phys.k2 = phys.kp; }
if (phys.k1 > phys.k2) { phys.k1 = phys.k2; }
phys.DeltMin = (phys.k2 - phys.k1) / (phys.k2 + phys.kc);
if (Delt > phys.DeltMax) {
phys.DeltMax = Delt;
phys.DeltNull = math::min((1.0 - phys.k1 / phys.k2) * phys.DeltMax, phys.DeltPNull); // [Luding2008], equation over Fig 1
// [Singh2013], equation (8)
}
Real k2DeltTtmp = phys.k2 * (Delt - phys.DeltNull); // [Luding2008], equation (6)
// [Singh2013], equation (6)
if (k2DeltTtmp >= phys.k1 * Delt) {
if (Delt < phys.DeltPMax) {
forceHys = phys.k1 * Delt;
} else {
forceHys = k2DeltTtmp;
}
} else if (k2DeltTtmp > -phys.kc * Delt and k2DeltTtmp < phys.k1 * Delt) {
forceHys = k2DeltTtmp;
} else if (k2DeltTtmp <= -phys.kc * Delt) {
if ((Delt - phys.DeltPrev) < 0) {
forceHys = -phys.kc * Delt;
phys.DeltMax = Delt * (phys.k2 + phys.kc) / (phys.k2 - phys.k1); // [Singh2013], equation (9)
phys.DeltNull = math::min((1.0 - phys.k1 / phys.k2) * phys.DeltMax, phys.DeltPNull); // [Luding2008], equation over Fig 1
// [Singh2013], equation (8)
} else {
forceHys = k2DeltTtmp;
}
}
phys.DeltPrev = Delt;
//===================================================================
//===================================================================
//===================================================================
// Copy-paste from ViscoElasticPM
Vector3r& shearForce = phys.shearForce;
if (I->isFresh(scene)) shearForce = Vector3r(0, 0, 0);
const Real& dt = scene->dt;
shearForce = geom.rotate(shearForce);
// Handle periodicity.
const Vector3r shift2 = scene->isPeriodic ? scene->cell->intrShiftPos(I->cellDist) : Vector3r::Zero();
const Vector3r shiftVel = scene->isPeriodic ? scene->cell->intrShiftVel(I->cellDist) : Vector3r::Zero();
const Vector3r c1x = (geom.contactPoint - de1.pos);
const Vector3r c2x = (geom.contactPoint - de2.pos - shift2);
const Vector3r relativeVelocity = (de1.vel + de1.angVel.cross(c1x)) - (de2.vel + de2.angVel.cross(c2x)) + shiftVel;
const Real normalVelocity = geom.normal.dot(relativeVelocity);
const Vector3r shearVelocity = relativeVelocity - normalVelocity * geom.normal;
shearForce += phys.ks * dt * shearVelocity; // the elastic shear force have a history, but
Vector3r shearForceVisc = Vector3r::Zero(); // the viscous shear damping haven't a history because it is a function of the instant velocity
phys.normalForce = (forceHys + phys.G0 * normalVelocity) * geom.normal;
const Real maxFs = phys.normalForce.squaredNorm() * math::pow(phys.tangensOfFrictionAngle, 2);
if (shearForce.squaredNorm() > maxFs) {
const Real ratio = sqrt(maxFs) / shearForce.norm();
shearForce *= ratio;
} else {
// shearForceVisc = phys.cs*shearVelocity; //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
shearForceVisc = phys.G0 * shearVelocity;
}
//===================================================================
//===================================================================
//===================================================================
if (I->isActive) {
const Vector3r f = phys.normalForce + shearForce + shearForceVisc;
addForce(id1, -f, scene);
addForce(id2, f, scene);
addTorque(id1, -c1x.cross(f), scene);
addTorque(id2, c2x.cross(f), scene);
}
return true;
}
} // namespace yade
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