SlidingFrictionSpecies.cc

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#include <cmath>
#include "SlidingFrictionSpecies.h"
#include "Species/NormalForceSpecies/LinearViscoelasticNormalSpecies.h"
#include "Species/BaseSpecies.h"
#include "Species/NormalForceSpecies/LinearPlasticViscoelasticNormalSpecies.h"

class BaseParticle;
class BaseInteractable;

SlidingFrictionSpecies::SlidingFrictionSpecies()
{
    slidingStiffness_ = 0;
    slidingDissipation_ = 0;
    slidingFrictionCoefficient_ = 0;
    slidingFrictionCoefficientStatic_ = 0;
#ifdef DEBUG_CONSTRUCTOR
    std::cout<<"SlidingFrictionSpecies::SlidingFrictionSpecies() finished"<<std::endl;
#endif
}

SlidingFrictionSpecies::SlidingFrictionSpecies(const SlidingFrictionSpecies &s)
{
    slidingStiffness_ = s.slidingStiffness_;
    slidingDissipation_ = s.slidingDissipation_;
    slidingFrictionCoefficient_ = s.slidingFrictionCoefficient_;
    slidingFrictionCoefficientStatic_ = s.slidingFrictionCoefficientStatic_;
#ifdef DEBUG_CONSTRUCTOR
    std::cout<<"SlidingFrictionSpecies::SlidingFrictionSpecies(const SlidingFrictionSpecies &p) finished"<<std::endl;
#endif
}

SlidingFrictionSpecies::~SlidingFrictionSpecies()
{
#ifdef DEBUG_DESTRUCTOR
    std::cout<<"SlidingFrictionSpecies::~SlidingFrictionSpecies() finished"<<std::endl;
#endif   
}

void SlidingFrictionSpecies::write(std::ostream& os) const
        {
    //BaseSpecies::write(os);
    os << " slidingStiffness " << slidingStiffness_;
    os << " slidingDissipation " << slidingDissipation_;
    os << " slidingFrictionCoefficient " << slidingFrictionCoefficient_;
    os << " slidingFrictionCoefficientStatic " << slidingFrictionCoefficientStatic_;
}

void SlidingFrictionSpecies::read(std::istream& is)
{
    //BaseSpecies::read(is);
    std::string dummy;
    is >> dummy >> slidingStiffness_;
    is >> dummy >> slidingDissipation_;
    is >> dummy >> slidingFrictionCoefficient_;
    is >> dummy >> slidingFrictionCoefficientStatic_;
}

std::string SlidingFrictionSpecies::getBaseName() const
{
    return "SlidingFriction";
}

void SlidingFrictionSpecies::setSlidingStiffness(Mdouble new_kt)
{
    if (new_kt >= 0)
    {
        slidingStiffness_ = new_kt;
    }
    else
    {
        std::cerr << "Error in setSlidingStiffness" << std::endl;
        exit(-1);
    }
}

Mdouble SlidingFrictionSpecies::getSlidingStiffness() const
{
    return slidingStiffness_;
}

void SlidingFrictionSpecies::setSlidingDissipation(Mdouble new_dispt)
{
    if (new_dispt >= 0)
        slidingDissipation_ = new_dispt;
    else
    {
        std::cerr << "Error in setSlidingDissipation" << std::endl;
        exit(-1);
    }
}
Mdouble SlidingFrictionSpecies::getSlidingDissipation() const
{
    return slidingDissipation_;
}

//mu has to be set to allow tangential forces (sets dispt=disp as default)
void SlidingFrictionSpecies::setSlidingFrictionCoefficient(Mdouble new_mu)
{
    if (new_mu >= 0)
    {
        slidingFrictionCoefficient_ = new_mu;
        slidingFrictionCoefficientStatic_ = slidingFrictionCoefficient_;
    }
    else
    {
        std::cerr << "Error in setSlidingFrictionCoefficient" << std::endl;
        exit(-1);
    }
}

Mdouble SlidingFrictionSpecies::getSlidingFrictionCoefficient() const
{
    return slidingFrictionCoefficient_;
}

void SlidingFrictionSpecies::setSlidingFrictionCoefficientStatic(Mdouble new_mu)
{
    if (new_mu >= 0)
    {
        slidingFrictionCoefficientStatic_ = new_mu;
    }
    else
    {
        std::cerr << "Error in setSlidingFrictionCoefficientStatic" << std::endl;
        exit(-1);
    }
}

Mdouble SlidingFrictionSpecies::getSlidingFrictionCoefficientStatic() const
{
    return slidingFrictionCoefficientStatic_;
}

bool SlidingFrictionSpecies::getUseAngularDOFs() const
{
    return true;
}

void SlidingFrictionSpecies::mix(SlidingFrictionSpecies* const SFrictional, SlidingFrictionSpecies* const TFrictional)
{
    slidingStiffness_ = average(SFrictional->getSlidingStiffness(), TFrictional->getSlidingStiffness());
    slidingDissipation_ = average(SFrictional->getSlidingDissipation(), TFrictional->getSlidingDissipation());
    slidingFrictionCoefficient_ = average(SFrictional->getSlidingFrictionCoefficient(), TFrictional->getSlidingFrictionCoefficient());
    slidingFrictionCoefficientStatic_ = average(SFrictional->getSlidingFrictionCoefficientStatic(), TFrictional->getSlidingFrictionCoefficientStatic());
}

void SlidingFrictionSpecies::setCollisionTimeAndNormalAndTangentialRestitutionCoefficient(Mdouble tc, Mdouble eps, Mdouble beta, Mdouble mass)
{
    Mdouble stiffness;
    //the dynamic cast is needed to check if the normal force species is LinearViscoelasticSpecies; otherwise this function cannot be used
    LinearViscoelasticNormalSpecies* species = dynamic_cast<LinearViscoelasticNormalSpecies*>(this);
    if (species!= nullptr)
    {
        species->setCollisionTimeAndRestitutionCoefficient(tc, eps, mass);
        stiffness = species->getStiffness();
    }
    else
    {
        LinearPlasticViscoelasticNormalSpecies* species2 = dynamic_cast<LinearPlasticViscoelasticNormalSpecies*>(this);
        if (species2 != nullptr)
        {
            species2->setDissipation(-mass / tc * std::log(eps));
            species2->setLoadingStiffness(.5 * mass * (mathsFunc::square(constants::pi/tc) + mathsFunc::square(species2->getDissipation()) /mass));
            stiffness = species2->getLoadingStiffness();
        }
        else
        {
            std::cerr << "SlidingFrictionSpecies::setCollisionTimeAndNormalAndTangentialRestitutionCoefficient only works for LinearViscoelasticSlidingFrictionSpecies or LinearPlasticViscoelasticSlidingFrictionSpecies" << std::endl;
            exit(-1);
        }
    }

    //from Deen...Kuipers2006, eq. 43 and 30
    setSlidingStiffness(2.0 / 7.0 * stiffness * (mathsFunc::square(constants::pi) + mathsFunc::square(log(beta))) / (mathsFunc::square(constants::pi) + mathsFunc::square(log(eps))));
    if (beta != 0.0)
        setSlidingDissipation(-2 * log(beta) * sqrt(1.0 / 7.0 * mass * getSlidingStiffness() / (mathsFunc::square(constants::pi) + mathsFunc::square(log(beta)))));
    else
        setSlidingDissipation(2. * sqrt(1.0 / 7.0 * mass * getSlidingStiffness()));
}

void SlidingFrictionSpecies::setCollisionTimeAndNormalAndTangentialRestitutionCoefficientNoDispt(Mdouble tc, Mdouble eps, Mdouble beta, Mdouble mass)
{
    //the dynamic cast is needed to check if the normal force species is LinearViscoelasticSpecies; otherwise this function cannot be used
    LinearViscoelasticNormalSpecies* species = dynamic_cast<LinearViscoelasticNormalSpecies*>(this);
    if (species == nullptr)
    {
        std::cerr << "SlidingFrictionSpecies::setCollisionTimeAndNormalAndTangentialRestitutionCoefficient only works for LinearViscoelasticSlidingFrictionSpecies" << std::endl;
        exit(-1);
    }
    species->setCollisionTimeAndRestitutionCoefficient(tc, eps, mass);
    //from BeckerSchwagerPoeschel2008, eq. 56
    setSlidingStiffness(2.0 / 7.0 * species->getStiffness() * mathsFunc::square(acos(-beta) / constants::pi));
    setSlidingDissipation(0);
}