SlidingFrictionUnitTest.cpp File Reference

#include "DPMBase.h"
#include <Species/LinearViscoelasticSlidingFrictionBondedSpecies.h>
#include <cassert>

Classes
class	SlidingFrictionUnitTest

Functions
int	main (int argc UNUSED, char *argv[] UNUSED)

Function Documentation

main()

int main	(	int argc	UNUSED,
		char *argv[]	UNUSED
	)

{
    //Unit diameter
    Mdouble radius = 0.5;
    //Equilibrium overlap
    Mdouble overlap = 0.1*radius;
    //Collision time (determines time step)
    Mdouble tc = 50e-3;
    //rotation velocity
    Mdouble velocity = 1.0;
 
    SlidingFrictionUnitTest sf;
    sf.setGravity({0,0,0});
    sf.setTimeStep(0.02*tc);
    sf.setName("SlidingFrictionUnitTest");
    sf.setMin(-radius*Vec3D(2,2,2));
    sf.setMax( radius*Vec3D(2,2,2));
    sf.setDimension(3);
    sf.setTimeMax(2.0);
    sf.eneFile.setSaveCount(1);
 
    //Add species
    auto s = sf.speciesHandler.copyAndAddObject(LinearViscoelasticSlidingFrictionBondedSpecies());
    //Set unit density
    s->setDensity(1.0);
    //Make particles relatively soft and dissipative
    Mdouble mass = s->getMassFromRadius(radius);
    s->setCollisionTimeAndNormalAndTangentialRestitutionCoefficient(tc,0.5,1.0,mass);
    //Set a high friction, so sliding movement is mostly elastic
    s->setSlidingFrictionCoefficient(1e20);
    //10% overlap in equilibrium position
    s->setBondForceMax(overlap*s->getStiffness());
    // check that stiffness is not too small
    logger(INFO,"Stiffness k=%",s->getStiffness());
 
    //Add particles
    SphericalParticle p;
    p.setSpecies(s);
    p.setRadius(radius);
    p.setPosition({ radius-0.5*overlap,0,0});
    p.setVelocity(velocity*Vec3D(0,0,1));
    auto p0 = sf.particleHandler.copyAndAddObject(p);
    p.setPosition({-radius+0.5*overlap,0,0});
    p.setVelocity(velocity*Vec3D(0,0,-1));
    auto p1 = sf.particleHandler.copyAndAddObject(p);
 
    //Add bonded interaction
    auto i = dynamic_cast<LinearViscoelasticSlidingFrictionBondedSpecies::InteractionType*>(sf.interactionHandler.getInteraction(p0,p1,0));
    i->bond();
    i->setSlidingSpring({0,0,overlap});
    sf.solve();
 
    helpers::writeToFile("SlidingFrictionUnitTest.gnu","set size ratio -1; p 'SlidingFrictionUnitTest.ene' u 2:4 w lp");
}

References BaseHandler< T >::copyAndAddObject(), DPMBase::eneFile, InteractionHandler::getInteraction(), constants::i, INFO, DPMBase::interactionHandler, logger, DPMBase::particleHandler, DPMBase::setDimension(), DPMBase::setGravity(), DPMBase::setMax(), DPMBase::setMin(), DPMBase::setName(), BaseInteractable::setPosition(), BaseParticle::setRadius(), File::setSaveCount(), BaseParticle::setSpecies(), DPMBase::setTimeMax(), DPMBase::setTimeStep(), BaseInteractable::setVelocity(), DPMBase::solve(), DPMBase::speciesHandler, and helpers::writeToFile().