MindlinRollingTorsionSpecies Class Reference

MindlinRollingTorsionSpecies contains the parameters used to describe sliding, rolling and torsional friction. More...

#include <MindlinRollingTorsionSpecies.h>

Inheritance diagram for MindlinRollingTorsionSpecies:

Public Types
typedef MindlinRollingTorsionInteraction	InteractionType
	The correct Interaction type for this FrictionForceSpecies. More...
Public Types inherited from MindlinSpecies
typedef MindlinInteraction	InteractionType
	The correct Interaction type for this FrictionForceSpecies. More...

Public Member Functions
	MindlinRollingTorsionSpecies ()
	The default constructor. More...
	MindlinRollingTorsionSpecies (const MindlinRollingTorsionSpecies &s)
	The default copy constructor. More...
	~MindlinRollingTorsionSpecies ()
	The default destructor. More...
void	read (std::istream &is)
	Reads the species properties from an input stream. More...
void	write (std::ostream &os) const
	Writes the species properties to an output stream. More...
std::string	getBaseName () const override
	Used in Species::getName to obtain a unique name for each Species. More...
bool	getUseAngularDOFs () const override
	Returns true if torques have to be calculated. More...
void	mix (MindlinRollingTorsionSpecies *S, MindlinRollingTorsionSpecies *T)
	creates default values for mixed species More...
void	setRollingDissipation (Mdouble new_dispt)
	Allows the spring constant to be changed. More...
Mdouble	getRollingDissipation () const
	Allows the tangential viscosity to be accessed. More...
void	setRollingFrictionCoefficient (Mdouble new_mu)
	Allows the (dynamic) Coulomb friction coefficient to be changed; also sets mu_s by default. More...
Mdouble	getRollingFrictionCoefficient () const
	Allows the (dynamic) Coulomb friction coefficient to be accessed. More...
void	setRollingFrictionCoefficientStatic (Mdouble new_mu)
	Allows the static Coulomb rolling friction coefficient to be changed. More...
Mdouble	getRollingFrictionCoefficientStatic () const
	Allows the static Coulomb rolling friction coefficient to be accessed. More...
void	setTorsionDissipation (Mdouble new_dispt)
	Allows the torsion viscosity to be changed. More...
Mdouble	getTorsionDissipation () const
	Allows the torsion viscosity to be accessed. More...
void	setTorsionFrictionCoefficient (Mdouble new_mu)
	Allows the (dynamic) Coulomb torsion friction coefficient to be changed; also sets mu_s by default. More...
Mdouble	getTorsionFrictionCoefficient () const
	Allows the (dynamic) Coulomb torsion friction coefficient to be accessed. More...
void	setTorsionFrictionCoefficientStatic (Mdouble new_mu)
	Allows the static Coulomb torsion friction coefficient to be accessed. More...
Mdouble	getTorsionFrictionCoefficientStatic () const
	Allows the static Coulomb torsion friction coefficient to be accessed. More...
Public Member Functions inherited from MindlinSpecies
	MindlinSpecies ()
	The default constructor. More...
	MindlinSpecies (const MindlinSpecies &s)
	The default copy constructor. More...
	~MindlinSpecies ()
	The default destructor. More...
void	read (std::istream &is)
	Reads the species properties from an input stream. More...
void	write (std::ostream &os) const
	Writes the species properties to an output stream. More...
void	setSlidingDissipation (Mdouble new_dispt)
	Allows the tangential viscosity to be changed. More...
Mdouble	getSlidingDissipation () const
	Allows the tangential viscosity to be accessed. More...
void	setSlidingFrictionCoefficient (Mdouble new_mu)
	Allows the (dynamic) Coulomb friction coefficient to be changed; also sets mu_s by default. More...
Mdouble	getSlidingFrictionCoefficient () const
	Allows the (dynamic) Coulomb friction coefficient to be accessed. More...
void	setSlidingFrictionCoefficientStatic (Mdouble new_mu)
	Allows the static Coulomb friction coefficient to be changed. More...
Mdouble	getSlidingFrictionCoefficientStatic () const
	Allows the static Coulomb friction coefficient to be accessed. More...
MERCURYDPM_DEPRECATED void	setPoissonRatio (Mdouble poissonRatio)
	Allows the poisson ratio to be changed. More...
void	setEffectiveShearModulus (Mdouble shearModulus)
	allows the shear modulus to be changed More...
Mdouble	getEffectiveShearModulus () const
	Allows the shear modulus to be accessed. More...
bool	getUseAngularDOFs () const override
	Returns true if torques have to be calculated. More...
void	mix (MindlinSpecies *S, MindlinSpecies *T)
	creates default values for mixed species More...
Public Member Functions inherited from BaseForce
BaseSpecies *	getBaseSpecies () const
void	setBaseSpecies (BaseSpecies *baseSpecies)

Private Attributes
Mdouble	rollingStiffness_
	rolling stiffness. More...
Mdouble	rollingDissipation_
	rolling dissipation coefficient. More...
Mdouble	rollingFrictionCoefficient_
	(dynamic) Coulomb rolling friction coefficient. More...
Mdouble	rollingFrictionCoefficientStatic_
	static Coulomb rolling friction coefficient (by default set equal to the dynamic one). More...
Mdouble	torsionStiffness_
	rolling stiffness. More...
Mdouble	torsionDissipation_
	rolling dissipation coefficient. More...
Mdouble	torsionFrictionCoefficient_
	(dynamic) Coulomb torsion friction coefficient. More...
Mdouble	torsionFrictionCoefficientStatic_
	static Coulomb torsion friction coefficient (by default set equal to the dynamic one). More...

Detailed Description

MindlinRollingTorsionSpecies contains the parameters used to describe sliding, rolling and torsional friction.

See FrictionInteraction::computeForce for a description of the force law.

Todo:

TW: should this class be renamed SlidingRollingTorsionMindlinRollingTorsionSpecies?

Member Typedef Documentation

InteractionType

typedef MindlinRollingTorsionInteraction MindlinRollingTorsionSpecies::InteractionType

The correct Interaction type for this FrictionForceSpecies.

Constructor & Destructor Documentation

MindlinRollingTorsionSpecies() [1/2]

MindlinRollingTorsionSpecies::MindlinRollingTorsionSpecies

(

)

The default constructor.

        : MindlinSpecies()
{
    rollingStiffness_ = 0.0;
    rollingDissipation_ = 0.0;
    rollingFrictionCoefficient_ = 0.0;
    rollingFrictionCoefficientStatic_ = 0.0;
    torsionStiffness_ = 0.0;
    torsionDissipation_ = 0.0;
    torsionFrictionCoefficient_ = 0.0;
    torsionFrictionCoefficientStatic_ = 0.0;
#ifdef DEBUG_CONSTRUCTOR
    std::cout<<"MindlinRollingTorsionSpecies::MindlinRollingTorsionSpecies() finished"<<std::endl;
#endif
}

References rollingDissipation_, rollingFrictionCoefficient_, rollingFrictionCoefficientStatic_, rollingStiffness_, torsionDissipation_, torsionFrictionCoefficient_, torsionFrictionCoefficientStatic_, and torsionStiffness_.

MindlinRollingTorsionSpecies() [2/2]

MindlinRollingTorsionSpecies::MindlinRollingTorsionSpecies

(

const MindlinRollingTorsionSpecies &

s

)

The default copy constructor.

Parameters

[in]

s

the species that is copied

        : MindlinSpecies(s)
{
    rollingStiffness_ = s.rollingStiffness_;
    rollingDissipation_ = s.rollingDissipation_;
    rollingFrictionCoefficient_ = s.rollingFrictionCoefficient_;
    rollingFrictionCoefficientStatic_ = s.rollingFrictionCoefficientStatic_;
    torsionStiffness_ = s.torsionStiffness_;
    torsionDissipation_ = s.torsionDissipation_;
    torsionFrictionCoefficient_ = s.torsionFrictionCoefficient_;
    torsionFrictionCoefficientStatic_ = s.torsionFrictionCoefficientStatic_;
#ifdef DEBUG_CONSTRUCTOR
    std::cout<<"MindlinRollingTorsionSpecies::MindlinRollingTorsionSpecies(const MindlinRollingTorsionSpecies &p) finished"<<std::endl;
#endif
}

References rollingDissipation_, rollingFrictionCoefficient_, rollingFrictionCoefficientStatic_, rollingStiffness_, torsionDissipation_, torsionFrictionCoefficient_, torsionFrictionCoefficientStatic_, and torsionStiffness_.

~MindlinRollingTorsionSpecies()

MindlinRollingTorsionSpecies::~MindlinRollingTorsionSpecies

(

)

The default destructor.

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

Member Function Documentation

getBaseName()

std::string MindlinRollingTorsionSpecies::getBaseName ( ) const

overridevirtual

Used in Species::getName to obtain a unique name for each Species.

Returns

a string containing the name of the species (minus the word "Species")

Reimplemented from MindlinSpecies.

{
    return "MindlinRollingTorsion";
}

getRollingDissipation()

Mdouble MindlinRollingTorsionSpecies::getRollingDissipation

(

)

const

Allows the tangential viscosity to be accessed.

{
    return rollingDissipation_;
}

References rollingDissipation_.

Referenced by MindlinRollingTorsionInteraction::computeFrictionForce(), and mix().

getRollingFrictionCoefficient()

Mdouble MindlinRollingTorsionSpecies::getRollingFrictionCoefficient

(

)

const

Allows the (dynamic) Coulomb friction coefficient to be accessed.

{
    return rollingFrictionCoefficient_;
}

References rollingFrictionCoefficient_.

Referenced by MindlinRollingTorsionInteraction::computeFrictionForce(), and mix().

getRollingFrictionCoefficientStatic()

Mdouble MindlinRollingTorsionSpecies::getRollingFrictionCoefficientStatic

(

)

const

Allows the static Coulomb rolling friction coefficient to be accessed.

Allows the static Coulomb friction coefficient to be accessed.

{
    return rollingFrictionCoefficientStatic_;
}

References rollingFrictionCoefficientStatic_.

Referenced by MindlinRollingTorsionInteraction::computeFrictionForce(), and mix().

getTorsionDissipation()

Mdouble MindlinRollingTorsionSpecies::getTorsionDissipation

(

)

const

Allows the torsion viscosity to be accessed.

Allows the tangential viscosity to be accessed.

{
    return torsionDissipation_;
}

References torsionDissipation_.

Referenced by MindlinRollingTorsionInteraction::computeFrictionForce(), and mix().

getTorsionFrictionCoefficient()

Mdouble MindlinRollingTorsionSpecies::getTorsionFrictionCoefficient

(

)

const

Allows the (dynamic) Coulomb torsion friction coefficient to be accessed.

Allows the (dynamic) Coulomb friction coefficient to be accessed.

{
    return torsionFrictionCoefficient_;
}

References torsionFrictionCoefficient_.

Referenced by MindlinRollingTorsionInteraction::computeFrictionForce(), and mix().

getTorsionFrictionCoefficientStatic()

Mdouble MindlinRollingTorsionSpecies::getTorsionFrictionCoefficientStatic

(

)

const

Allows the static Coulomb torsion friction coefficient to be accessed.

Allows the static Coulomb friction coefficient to be accessed.

{
    return torsionFrictionCoefficientStatic_;
}

References torsionFrictionCoefficientStatic_.

Referenced by MindlinRollingTorsionInteraction::computeFrictionForce(), and mix().

getUseAngularDOFs()

bool MindlinRollingTorsionSpecies::getUseAngularDOFs ( ) const

overridevirtual

Returns true if torques have to be calculated.

Returns true for any FrictionForceSpecies except EmptyMindlinRollingTorsionSpecies, because for spherical particles, torques are only caused by tangential forces. See SpeciesHandler::useAngularDOFs for more details

Returns

true

Implements BaseFrictionForce.

{
    return true;
}

mix()

void MindlinRollingTorsionSpecies::mix	(	MindlinRollingTorsionSpecies *	S,
		MindlinRollingTorsionSpecies *	T
	)

creates default values for mixed species

For all parameters we assume that the harmonic mean of the parameters of the original two species is a sensible default.

Parameters

[in]

S,T

the two species whose properties are mixed to create the new species

{
    //rollingStiffness_= BaseSpecies::average(S->getRollingStiffness(), T->getRollingStiffness());
    rollingDissipation_ = BaseSpecies::average(S->getRollingDissipation(), T->getRollingDissipation());
    rollingFrictionCoefficient_ = BaseSpecies::average(S->getRollingFrictionCoefficient(), T->getRollingFrictionCoefficient());
    rollingFrictionCoefficientStatic_ = BaseSpecies::average(S->getRollingFrictionCoefficientStatic(),
                                                T->getRollingFrictionCoefficientStatic());
    //torsionStiffness_= BaseSpecies::average(S->getTorsionStiffness(), T->getTorsionStiffness());
    torsionDissipation_ = BaseSpecies::average(S->getTorsionDissipation(), T->getTorsionDissipation());
    torsionFrictionCoefficient_ = BaseSpecies::average(S->getTorsionFrictionCoefficient(), T->getTorsionFrictionCoefficient());
    torsionFrictionCoefficientStatic_ = BaseSpecies::average(S->getTorsionFrictionCoefficientStatic(),
                                                T->getTorsionFrictionCoefficientStatic());
}

References BaseSpecies::average(), getRollingDissipation(), getRollingFrictionCoefficient(), getRollingFrictionCoefficientStatic(), getTorsionDissipation(), getTorsionFrictionCoefficient(), getTorsionFrictionCoefficientStatic(), rollingDissipation_, rollingFrictionCoefficient_, rollingFrictionCoefficientStatic_, torsionDissipation_, torsionFrictionCoefficient_, and torsionFrictionCoefficientStatic_.

read()

void MindlinRollingTorsionSpecies::read

(

std::istream &

is

)

Reads the species properties from an input stream.

Parameters

[in]

is

input stream (typically the restart file)

{
    MindlinSpecies::read(is);
    std::string dummy;
    is >> dummy >> rollingStiffness_;
    is >> dummy >> rollingDissipation_;
    is >> dummy >> rollingFrictionCoefficient_;
    is >> dummy >> rollingFrictionCoefficientStatic_;
    is >> dummy >> torsionStiffness_;
    is >> dummy >> torsionDissipation_;
    is >> dummy >> torsionFrictionCoefficient_;
    is >> dummy >> torsionFrictionCoefficientStatic_;
}

References MindlinSpecies::read(), rollingDissipation_, rollingFrictionCoefficient_, rollingFrictionCoefficientStatic_, rollingStiffness_, torsionDissipation_, torsionFrictionCoefficient_, torsionFrictionCoefficientStatic_, and torsionStiffness_.

setRollingDissipation()

void MindlinRollingTorsionSpecies::setRollingDissipation

(

Mdouble

new_dispt

)

Allows the spring constant to be changed.

Allows the tangential viscosity to be changed.

Allows the spring constant to be accessed Allows the tangential viscosity to be changed

{
    if (new_dispt >= 0)
        rollingDissipation_ = new_dispt;
    else
    {
        logger(ERROR, "Error in setRollingDissipation");
    }
}

References ERROR, logger, and rollingDissipation_.

setRollingFrictionCoefficient()

void MindlinRollingTorsionSpecies::setRollingFrictionCoefficient

(

Mdouble

new_mu

)

Allows the (dynamic) Coulomb friction coefficient to be changed; also sets mu_s by default.

{
    if (new_mu >= 0)
    {
        rollingFrictionCoefficient_ = new_mu;
        rollingFrictionCoefficientStatic_ = rollingFrictionCoefficient_;
    }
    else
    {
        logger(ERROR, "Error in setSlidingFrictionCoefficient");
    }
}

References ERROR, logger, rollingFrictionCoefficient_, and rollingFrictionCoefficientStatic_.

setRollingFrictionCoefficientStatic()

void MindlinRollingTorsionSpecies::setRollingFrictionCoefficientStatic

(

Mdouble

new_mu

)

Allows the static Coulomb rolling friction coefficient to be changed.

Allows the static Coulomb friction coefficient to be changed; also sets mu_s by default.

{
    if (new_mu >= 0)
    {
        rollingFrictionCoefficientStatic_ = new_mu;
    }
    else
    {
        logger(ERROR, "Error in setSlidingFrictionCoefficientStatic");
    }
}

References ERROR, logger, and rollingFrictionCoefficientStatic_.

setTorsionDissipation()

void MindlinRollingTorsionSpecies::setTorsionDissipation

(

Mdouble

new_dispt

)

Allows the torsion viscosity to be changed.

Allows the tangential viscosity to be changed.

{
    if (new_dispt >= 0)
        torsionDissipation_ = new_dispt;
    else
    {
        logger(ERROR, "Error in setTorsionDissipation");
    }
}

References ERROR, logger, and torsionDissipation_.

setTorsionFrictionCoefficient()

void MindlinRollingTorsionSpecies::setTorsionFrictionCoefficient

(

Mdouble

new_mu

)

Allows the (dynamic) Coulomb torsion friction coefficient to be changed; also sets mu_s by default.

Allows the (dynamic) Coulomb friction coefficient to be changed; also sets mu_s by default.

{
    if (new_mu >= 0)
    {
        torsionFrictionCoefficient_ = new_mu;
        torsionFrictionCoefficientStatic_ = torsionFrictionCoefficient_;
    }
    else
    {
        logger(ERROR, "Error in setSlidingFrictionCoefficient");
    }
}

References ERROR, logger, torsionFrictionCoefficient_, and torsionFrictionCoefficientStatic_.

setTorsionFrictionCoefficientStatic()

void MindlinRollingTorsionSpecies::setTorsionFrictionCoefficientStatic

(

Mdouble

new_mu

)

Allows the static Coulomb torsion friction coefficient to be accessed.

Allows the static Coulomb friction coefficient to be changed; also sets mu_s by default.

{
    if (new_mu >= 0)
    {
        torsionFrictionCoefficientStatic_ = new_mu;
    }
    else
    {
        logger(ERROR, "Error in setSlidingFrictionCoefficientStatic");
    }
}

References ERROR, logger, and torsionFrictionCoefficientStatic_.

write()

void MindlinRollingTorsionSpecies::write

(

std::ostream &

os

)

const

Writes the species properties to an output stream.

Parameters

[out]

os

output stream (typically the restart file)

{
    MindlinSpecies::write(os);
    os << " rollingStiffness " << rollingStiffness_;
    os << " rollingDissipation " << rollingDissipation_;
    os << " rollingFrictionCoefficient " << rollingFrictionCoefficient_;
    os << " rollingFrictionCoefficientStatic " << rollingFrictionCoefficientStatic_;
    os << " torsionStiffness " << torsionStiffness_;
    os << " torsionDissipation " << torsionDissipation_;
    os << " torsionFrictionCoefficient " << torsionFrictionCoefficient_;
    os << " torsionFrictionCoefficientStatic " << torsionFrictionCoefficientStatic_;
}

References rollingDissipation_, rollingFrictionCoefficient_, rollingFrictionCoefficientStatic_, rollingStiffness_, torsionDissipation_, torsionFrictionCoefficient_, torsionFrictionCoefficientStatic_, torsionStiffness_, and MindlinSpecies::write().

Member Data Documentation

rollingDissipation_

Mdouble MindlinRollingTorsionSpecies::rollingDissipation_

private

rolling dissipation coefficient.

Typically set to 2/5 of the normal force dissipation, as both the tangential and the normal spring have the same restitution coefficients (if the rolling and normal stiffnesses also have a ratio of 2/5).

Referenced by getRollingDissipation(), MindlinRollingTorsionSpecies(), mix(), read(), setRollingDissipation(), and write().

rollingFrictionCoefficient_

Mdouble MindlinRollingTorsionSpecies::rollingFrictionCoefficient_

private

(dynamic) Coulomb rolling friction coefficient.

Referenced by getRollingFrictionCoefficient(), MindlinRollingTorsionSpecies(), mix(), read(), setRollingFrictionCoefficient(), and write().

rollingFrictionCoefficientStatic_

Mdouble MindlinRollingTorsionSpecies::rollingFrictionCoefficientStatic_

private

static Coulomb rolling friction coefficient
(by default set equal to the dynamic one).

Referenced by getRollingFrictionCoefficientStatic(), MindlinRollingTorsionSpecies(), mix(), read(), setRollingFrictionCoefficient(), setRollingFrictionCoefficientStatic(), and write().

rollingStiffness_

Mdouble MindlinRollingTorsionSpecies::rollingStiffness_

private

rolling stiffness.

Typically set to 2/5 of the stiffness of the normal force, as
both the rolling and the normal spring have the same oscillation
frequency (and thus require the same timeStep) in this case.

Referenced by MindlinRollingTorsionSpecies(), read(), and write().

torsionDissipation_

Mdouble MindlinRollingTorsionSpecies::torsionDissipation_

private

rolling dissipation coefficient.

Typically set to 2/5 of the normal force dissipation, as both the tangential and the normal spring have the same restitution coefficients (if the rolling and normal stiffnesses also have a ratio of 2/5).

Referenced by getTorsionDissipation(), MindlinRollingTorsionSpecies(), mix(), read(), setTorsionDissipation(), and write().

torsionFrictionCoefficient_

Mdouble MindlinRollingTorsionSpecies::torsionFrictionCoefficient_

private

(dynamic) Coulomb torsion friction coefficient.

Referenced by getTorsionFrictionCoefficient(), MindlinRollingTorsionSpecies(), mix(), read(), setTorsionFrictionCoefficient(), and write().

torsionFrictionCoefficientStatic_

Mdouble MindlinRollingTorsionSpecies::torsionFrictionCoefficientStatic_

private

static Coulomb torsion friction coefficient
(by default set equal to the dynamic one).

Referenced by getTorsionFrictionCoefficientStatic(), MindlinRollingTorsionSpecies(), mix(), read(), setTorsionFrictionCoefficient(), setTorsionFrictionCoefficientStatic(), and write().

torsionStiffness_

Mdouble MindlinRollingTorsionSpecies::torsionStiffness_

private

rolling stiffness.

Typically set to 2/5 of the stiffness of the normal force, as
both the rolling and the normal spring have the same oscillation
frequency (and thus require the same timeStep)in this case.

Referenced by MindlinRollingTorsionSpecies(), read(), and write().

---

The documentation for this class was generated from the following files:

• MindlinRollingTorsionSpecies.h
• MindlinRollingTorsionSpecies.cc