FreeFallHertzMindlinUnitTest.cpp File Reference

#include "Mercury2D.h"
#include "Walls/InfiniteWall.h"
#include <Species/HertzianViscoelasticMindlinSpecies.h>

Classes
class	FreeFallHertzMindlinUnitTest

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

Function Documentation

main()

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

{
    logger(INFO, "Single particle bouncing vertically on the bottom plate");
 
    //The monosized 3 mm perfect-spherical tungsten particles are simulated.
    //Poisson Ratio is 0.28,
    //bulk density is 19250 Kg/m^3,
    //Young modulus 4.11E11 Pa,
    //restitution coefficient is 0.95,
    //Hertz-Mindlin model is used to describe the contact force between neighboring particles.
    Mdouble poissonRatio = 0.28;
    Mdouble density = 10000*6.0/constants::pi;
    Mdouble elasticModulus = 4.11e11; //100 times too soft
    Mdouble restitution = 0.5;
 
    // Make the problem and set the name
    FreeFallHertzMindlinUnitTest dpm;
    dpm.setName("FreeFallHertzMindlinUnitTest");
    dpm.setGravity(Vec3D(0,-10,0));
    dpm.setParticleDimensions(3);
 
    //Set the species of the particle and wall, and its properties
    HertzianViscoelasticMindlinSpecies species;
    species.setDensity(density);
    species.setEffectiveElasticModulusAndRestitutionCoefficient(elasticModulus, restitution);
    //https://en.wikipedia.org/wiki/Shear_modulus#References
    species.setEffectiveShearModulus(0.5 * elasticModulus / (1 + poissonRatio));
    species.setSlidingFrictionCoefficient(1.0);
    dpm.speciesHandler.copyAndAddObject(species);
 
    //set the parameters for the solver
    dpm.setSaveCount(40);
    dpm.fStatFile.setFileType(FileType::NO_FILE);
    dpm.wallHandler.setWriteVTK(FileType::ONE_FILE);
    Mdouble relativeVelocity = 0.1;
    Mdouble tc = species.getCollisionTime(2.0*dpm.radius, species.getDensity(), relativeVelocity);
    logger(INFO,"Collision time %", tc);
    dpm.setTimeStep(0.02*tc);
    dpm.setTimeMax(0.1);
 
    //solve the system, the single particle will now bounce on the plate
    dpm.solve(argc, argv);
 
    helpers::writeToFile("FreeFallHertzMindlinUnitTest.gnu",
                         "set xlabel 't'; p 'FreeFallHertzMindlinUnitTest.ene' u 1:(sqrt($3)) t 'sqrt(E_kin)' w lp");
    logger(INFO,"type 'gnuplot FreeFallHertzMindlinUnitTest.gnu' to check energy conservation");
}

References BaseHandler< T >::copyAndAddObject(), DPMBase::fStatFile, ParticleSpecies::getDensity(), INFO, logger, NO_FILE, ONE_FILE, constants::pi, FreeFallHertzMindlinUnitTest::radius, ParticleSpecies::setDensity(), File::setFileType(), DPMBase::setGravity(), DPMBase::setName(), DPMBase::setParticleDimensions(), DPMBase::setSaveCount(), DPMBase::setTimeMax(), DPMBase::setTimeStep(), WallHandler::setWriteVTK(), DPMBase::solve(), DPMBase::speciesHandler, DPMBase::wallHandler, and helpers::writeToFile().