EnergyUnitTest.cpp File Reference

#include "Species/LinearViscoelasticIrreversibleAdhesiveSpecies.h"
#include "Species/LinearViscoelasticReversibleAdhesiveSpecies.h"
#include "DPMBase.h"
#include "Logger.h"
#include "Species/LinearPlasticViscoelasticReversibleAdhesiveSpecies.h"

Classes
class	EnergyUnitTest

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

Function Documentation

main()

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

Todo:

TW The inaccuracy of the calculation is much worse for the irreversible force model, as there is a jump in force at zero overlap; we should correct for that in the time stepping algorithm (i.e. find out what the mean force was over the duration of the time step, not using a left Riemann sum.

{
    logger(INFO, "Test if the LinearViscoelasticReversibleAdhesiveInteraction conserves energy");
    EnergyUnitTest energyUnitTest;
    energyUnitTest.setName("ReversibleAdhesiveEnergyUnitTest");
    LinearViscoelasticReversibleAdhesiveSpecies species1;
    species1.setDensity(6.0 / constants::pi);
    species1.setStiffness(500);
    species1.setAdhesionStiffness(100);
    species1.setAdhesionForceMax(10);
    //std::cout << "maxVelocity=" << species1.getMaximumVelocity(0.5, 1.0) << std::endl;
    energyUnitTest.setTimeStep(0.002 * species1.getCollisionTime(1.0));
    //std::cout << "timeStep=" << energyUnitTest.getTimeStep() << std::endl;
    energyUnitTest.setSaveCount(3);
    energyUnitTest.setTimeMax(0.4);
    energyUnitTest.speciesHandler.copyAndAddObject(species1);
    energyUnitTest.solve();
    Mdouble lostEnergy = mathsFunc::square(0.7) - energyUnitTest.getElasticEnergy() - energyUnitTest.getKineticEnergy();
    if (!mathsFunc::isEqual(lostEnergy, 0.0, 1e-6))
    {
        logger(ERROR, "energy loss is %, but should be %", lostEnergy, 0.0);
    }
    
    logger(INFO, "Test if the LinearViscoelasticIrreversibleAdhesiveInteraction looses the right amount of energy\n",
           Flusher::NO_FLUSH);
    EnergyUnitTest energyUnitTest2;
    energyUnitTest2.setName("IrreversibleAdhesiveEnergyUnitTest");
    LinearViscoelasticIrreversibleAdhesiveSpecies species2;
    species2.setDensity(6.0 / constants::pi);
    species2.setStiffness(500);
    species2.setAdhesionStiffness(100);
    species2.setAdhesionForceMax(10);
    logger(INFO, "maxVelocity=%\n", species2.getMaximumVelocity(0.5, 1.0), Flusher::NO_FLUSH);
    //this test is 10 times more accurate than the previous one, as the error is so much bigger.
    energyUnitTest2.setTimeStep(0.0002 * species2.getCollisionTime(1.0));
    logger(INFO, "timeStep=%\n", energyUnitTest2.getTimeStep());
    energyUnitTest2.setSaveCount(3);
    energyUnitTest2.setTimeMax(0.2);
    energyUnitTest2.speciesHandler.copyAndAddObject(species2);
    energyUnitTest2.solve();
    lostEnergy = mathsFunc::square(0.7)-energyUnitTest2.getElasticEnergy()-energyUnitTest2.getKineticEnergy();
    if (!mathsFunc::isEqual(lostEnergy, 0.5, 1e-4))
    {
        logger(ERROR, "energy loss is %, but should be %", lostEnergy, 0.5);
    }
 
    return 0;
}

References BaseHandler< T >::copyAndAddObject(), e(), ERROR, DPMBase::getElasticEnergy(), DPMBase::getKineticEnergy(), DPMBase::getTimeStep(), INFO, mathsFunc::isEqual(), logger, NO_FLUSH, constants::pi, ParticleSpecies::setDensity(), DPMBase::setName(), DPMBase::setSaveCount(), DPMBase::setTimeMax(), DPMBase::setTimeStep(), DPMBase::solve(), DPMBase::speciesHandler, and mathsFunc::square().