HertzianSinterNormalSpecies Class Reference

HertzianSinterNormalSpecies contains the parameters used to describe a plastic-cohesive normal force (Stefan Ludings plastic-cohesive force model). More...

#include <HertzianSinterNormalSpecies.h>

Inheritance diagram for HertzianSinterNormalSpecies:

Public Types
typedef HertzianSinterInteraction	InteractionType
	The correct Interaction type for this FrictionForceSpecies. More...

Public Member Functions
	HertzianSinterNormalSpecies ()
	The default constructor. More...
	HertzianSinterNormalSpecies (const HertzianSinterNormalSpecies &p)
	The default copy constructor. More...
	~HertzianSinterNormalSpecies ()
	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
	Used in Species::getName to obtain a unique name for each Species. More...
void	mix (HertzianSinterNormalSpecies *S, HertzianSinterNormalSpecies *T)
	creates default values for mixed species More...
void	setPlasticParameters (Mdouble loadingModulus, Mdouble unloadingModulusMax, Mdouble cohesionModulus, Mdouble penetrationDepthMax)
	Sets all parameters of the linear plastic-viscoelastic normal force at once. More...
Mdouble	getLoadingModulus () const
	Returns the loading stiffness of the linear plastic-viscoelastic normal force. More...
Mdouble	getUnloadingModulusMax () const
	Returns the maximum unloading stiffness of the linear plastic-viscoelastic normal force. More...
Mdouble	getCohesionModulus () const
	Returns the cohesive stiffness of the linear plastic-viscoelastic normal force. More...
Mdouble	getPenetrationDepthMax () const
	Returns the maximum penetration depth of the linear plastic-viscoelastic normal force. More...
void	setLoadingModulus (Mdouble loadingModulus)
	Sets the loading stiffness of the linear plastic-viscoelastic normal force. More...
void	setUnloadingModulusMax (Mdouble unloadingModulusMax)
	Sets the maximum unloading stiffness of the linear plastic-viscoelastic normal force. More...
void	setCohesionModulus (Mdouble cohesionModulus)
	Sets the cohesive stiffness of the linear plastic-viscoelastic normal force. More...
void	setPenetrationDepthMax (Mdouble penetrationDepthMax)
	Sets the maximum penetration depth of the linear plastic-viscoelastic normal force. More...
void	setDissipation (Mdouble dissipation)
	Sets the linear dissipation coefficient of the linear plastic-viscoelastic normal force. More...
Mdouble	getDissipation () const
	Allows the normal dissipation to be accessed. More...
void	setSinterRate (Mdouble sinterRate)
	Sets the linear dissipation coefficient of the linear plastic-viscoelastic normal force. More...
Mdouble	getSinterRate () const
	Allows the normal dissipation to be accessed. More...
Mdouble	computeTimeStep (Mdouble mass)
	Returns the optimal time step to resolve a collision of two particles of a given mass. More...
Public Member Functions inherited from BaseNormalForce
	BaseNormalForce ()
	BaseNormalForce (const BaseNormalForce &p)
bool	getConstantRestitution () const
void	setConstantRestitution (bool constantRestitution)
virtual void	actionsAfterTimeStep (BaseParticle *particle) const
Public Member Functions inherited from BaseForce
BaseSpecies *	getBaseSpecies () const
void	setBaseSpecies (BaseSpecies *baseSpecies)

Private Attributes
Mdouble	loadingModulus_
	(normal) spring constant (k_1) More...
Mdouble	unloadingModulusMax_
	the maximum elastic constant (k_2^max) for plastic deformations More...
Mdouble	cohesionModulus_
	the adhesive spring constant (k^c) for plastic deformations More...
Mdouble	penetrationDepthMax_
	the depth (relative to the normalized radius) at which k_2^max is used (phi_f) More...
Mdouble	dissipation_
	linear dissipation coefficient More...
Mdouble	sinterRate_

Detailed Description

HertzianSinterNormalSpecies contains the parameters used to describe a plastic-cohesive normal force (Stefan Ludings plastic-cohesive force model).

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

Member Typedef Documentation

InteractionType

typedef HertzianSinterInteraction HertzianSinterNormalSpecies::InteractionType

The correct Interaction type for this FrictionForceSpecies.

Constructor & Destructor Documentation

HertzianSinterNormalSpecies() [1/2]

HertzianSinterNormalSpecies::HertzianSinterNormalSpecies

(

)

The default constructor.

        : BaseNormalForce()
{
    loadingModulus_ = 0.0;
    unloadingModulusMax_ = 0.0;
    cohesionModulus_ = 0.0;
    penetrationDepthMax_ = 0.0;
    dissipation_ = 0.0;
    sinterRate_ = 0.0;
#ifdef DEBUG_CONSTRUCTOR
    std::cout<<"HertzianSinterNormalSpecies::HertzianSinterNormalSpecies() finished"<<std::endl;
#endif
}

References cohesionModulus_, dissipation_, loadingModulus_, penetrationDepthMax_, sinterRate_, and unloadingModulusMax_.

HertzianSinterNormalSpecies() [2/2]

HertzianSinterNormalSpecies::HertzianSinterNormalSpecies

(

const HertzianSinterNormalSpecies &

p

)

The default copy constructor.

Parameters

[in]

the

species that is copied

        : BaseNormalForce(p)
{
    loadingModulus_ = p.loadingModulus_;
    unloadingModulusMax_ = p.unloadingModulusMax_;
    cohesionModulus_ = p.cohesionModulus_;
    penetrationDepthMax_ = p.penetrationDepthMax_;
    dissipation_ = p.dissipation_;
    sinterRate_ = p.sinterRate_;
#ifdef DEBUG_CONSTRUCTOR
    std::cout<<"HertzianSinterNormalSpecies::HertzianSinterNormalSpecies(const HertzianSinterNormalSpecies &p) finished"<<std::endl;
#endif
}

References cohesionModulus_, dissipation_, loadingModulus_, penetrationDepthMax_, sinterRate_, and unloadingModulusMax_.

~HertzianSinterNormalSpecies()

HertzianSinterNormalSpecies::~HertzianSinterNormalSpecies

(

)

The default destructor.

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

Member Function Documentation

computeTimeStep()

Mdouble HertzianSinterNormalSpecies::computeTimeStep

(

Mdouble

mass

)

Returns the optimal time step to resolve a collision of two particles of a given mass.

Calculates collision time for stiffest spring constant, divides by 50

Parameters

[in]

the

optimal time step is computed to resolve a collision of two particles of this mass.

{
//    if (stiffnessMax / (.5 * mass) < mathsFunc::square(dissipation_ /mass)) {
//        std::cerr << "Dissipation too high; max. allowed " << sqrt(2.0 * stiffnessMax * mass) << std::endl;
//        return 0.02 * constants::pi / std::sqrt(2.0*stiffnessMax / mass);
//    } else {
    logger(WARN, "Warning: Dissipation is not taken into account when computing the time step");
    ParticleSpecies* p = dynamic_cast<ParticleSpecies*>(getBaseSpecies());
    logger.assert_debug(p,"Empty particle handler");
    Mdouble radius = cbrt(mass * 3. / (4. * constants::pi * p->getDensity()));
    return 0.02 * constants::pi / std::sqrt(2.0 * getUnloadingModulusMax() * getPenetrationDepthMax() * radius / mass);
}

References BaseForce::getBaseSpecies(), ParticleSpecies::getDensity(), getPenetrationDepthMax(), getUnloadingModulusMax(), logger, constants::pi, and WARN.

getBaseName()

std::string HertzianSinterNormalSpecies::getBaseName

(

)

const

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")

{
    return "HertzianSinter";
}

getCohesionModulus()

Mdouble HertzianSinterNormalSpecies::getCohesionModulus

(

)

const

Returns the cohesive stiffness of the linear plastic-viscoelastic normal force.

Returns

the cohesive stiffness of the linear plastic-viscoelastic normal force.

{
    return cohesionModulus_;
}

References cohesionModulus_.

Referenced by HertzianSinterInteraction::computeSinterForce(), and mix().

getDissipation()

Mdouble HertzianSinterNormalSpecies::getDissipation

(

)

const

Allows the normal dissipation to be accessed.

Returns

the linear dissipation coefficient

{
    return dissipation_;
}

References dissipation_.

Referenced by HertzianSinterInteraction::computeSinterForce(), and mix().

getLoadingModulus()

Mdouble HertzianSinterNormalSpecies::getLoadingModulus

(

)

const

Returns the loading stiffness of the linear plastic-viscoelastic normal force.

Returns

the loading stiffness of the linear plastic-viscoelastic normal force.

{
    return loadingModulus_;
}

References loadingModulus_.

Referenced by HertzianSinterInteraction::computeSinterForce(), HertzianSinterInteraction::getElasticEnergy(), HertzianSinterInteraction::getUnloadingModulus(), and mix().

getPenetrationDepthMax()

Mdouble HertzianSinterNormalSpecies::getPenetrationDepthMax

(

)

const

Returns the maximum penetration depth of the linear plastic-viscoelastic normal force.

Returns

the maximum penetration depth of the linear plastic-viscoelastic normal force.

{
    return penetrationDepthMax_;
}

References penetrationDepthMax_.

Referenced by HertzianSinterInteraction::computeSinterForce(), computeTimeStep(), HertzianSinterInteraction::getUnloadingModulus(), and mix().

getSinterRate()

Mdouble HertzianSinterNormalSpecies::getSinterRate

(

)

const

Allows the normal dissipation to be accessed.

Returns

the linear dissipation coefficient

{
    return sinterRate_;
}

References sinterRate_.

Referenced by HertzianSinterInteraction::computeSinterForce(), and mix().

getUnloadingModulusMax()

Mdouble HertzianSinterNormalSpecies::getUnloadingModulusMax

(

)

const

Returns the maximum unloading stiffness of the linear plastic-viscoelastic normal force.

Returns

the maximum unloading stiffness of the linear plastic-viscoelastic normal force.

{
    return unloadingModulusMax_;
}

References unloadingModulusMax_.

Referenced by HertzianSinterInteraction::computeSinterForce(), computeTimeStep(), HertzianSinterInteraction::getUnloadingModulus(), and mix().

mix()

void HertzianSinterNormalSpecies::mix	(	HertzianSinterNormalSpecies *	S,
		HertzianSinterNormalSpecies *	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

{
    loadingModulus_ = BaseSpecies::average(S->getLoadingModulus(), T->getLoadingModulus());
    unloadingModulusMax_ = BaseSpecies::average(S->getUnloadingModulusMax(), T->getUnloadingModulusMax());
    cohesionModulus_ = BaseSpecies::average(S->getCohesionModulus(), T->getCohesionModulus());
    penetrationDepthMax_ = BaseSpecies::average(S->getPenetrationDepthMax(), T->getPenetrationDepthMax());
    dissipation_ = BaseSpecies::average(S->getDissipation(), T->getDissipation());
    sinterRate_ = BaseSpecies::average(S->getSinterRate(), T->getSinterRate());
}

References BaseSpecies::average(), cohesionModulus_, dissipation_, getCohesionModulus(), getDissipation(), getLoadingModulus(), getPenetrationDepthMax(), getSinterRate(), getUnloadingModulusMax(), loadingModulus_, penetrationDepthMax_, sinterRate_, and unloadingModulusMax_.

read()

void HertzianSinterNormalSpecies::read

(

std::istream &

is

)

Reads the species properties from an input stream.

Parameters

[in]

input

stream (typically the restart file)

{
    std::string dummy;
    is >> dummy >> loadingModulus_;
    is >> dummy >> unloadingModulusMax_;
    is >> dummy >> cohesionModulus_;
    is >> dummy >> penetrationDepthMax_;
    is >> dummy >> dissipation_;
    is >> dummy >> sinterRate_;
}

References cohesionModulus_, dissipation_, loadingModulus_, penetrationDepthMax_, sinterRate_, and unloadingModulusMax_.

setCohesionModulus()

void HertzianSinterNormalSpecies::setCohesionModulus

(

Mdouble

cohesionModulus

)

Sets the cohesive stiffness of the linear plastic-viscoelastic normal force.

Parameters

[in]

cohesionModulus

the cohesive stiffness of the linear plastic-viscoelastic normal force.

{
    cohesionModulus_ = cohesionModulus;
}

References cohesionModulus_.

Referenced by setPlasticParameters().

setDissipation()

void HertzianSinterNormalSpecies::setDissipation

(

Mdouble

dissipation

)

Sets the linear dissipation coefficient of the linear plastic-viscoelastic normal force.

should be non-negative

Parameters

[in]

the

linear dissipation coefficient of the linear plastic-viscoelastic normal force.

{
    if (dissipation >= 0)
    {
        dissipation_ = dissipation;
    }
    else
    {
        logger(ERROR, "setDissipation(%) argument has to be non-negative", dissipation);
    }
}

References dissipation_, ERROR, and logger.

setLoadingModulus()

void HertzianSinterNormalSpecies::setLoadingModulus

(

Mdouble

loadingModulus

)

Sets the loading stiffness of the linear plastic-viscoelastic normal force.

Parameters

[in]

loadingModulus

the loading stiffness of the linear plastic-viscoelastic normal force.

{
    loadingModulus_ = loadingModulus;
}

References loadingModulus_.

Referenced by setPlasticParameters().

setPenetrationDepthMax()

void HertzianSinterNormalSpecies::setPenetrationDepthMax

(

Mdouble

penetrationDepthMax

)

Sets the maximum penetration depth of the linear plastic-viscoelastic normal force.

Parameters

[in]

penetrationDepthMax

the maximum penetration depth of the linear plastic-viscoelastic normal force.

{
    penetrationDepthMax_ = penetrationDepthMax;
}

References penetrationDepthMax_.

Referenced by setPlasticParameters().

setPlasticParameters()

void HertzianSinterNormalSpecies::setPlasticParameters	(	Mdouble	loadingModulus,
		Mdouble	unloadingModulusMax,
		Mdouble	cohesionModulus,
		Mdouble	penetrationDepthMax
	)

Sets all parameters of the linear plastic-viscoelastic normal force at once.

Parameters

[in]	loadingModulus	the loading stiffness of the linear plastic-viscoelastic normal force.
[in]	unloadingModulusMax	the maximum unloading stiffness of the linear plastic-viscoelastic normal force.
[in]	cohesionModulus	the cohesive stiffness of the linear plastic-viscoelastic normal force.
[in]	penetrationDepthMax	the maximum penetration depth of the linear plastic-viscoelastic normal force.

{
    if (loadingModulus <= 0 || unloadingModulusMax <= 1.000001 * (loadingModulus + cohesionModulus) ||
        cohesionModulus < 0 || penetrationDepthMax < 0)
    {
        logger(ERROR, "Arguments of setPlasticParameters do not make sense");
    }
    setLoadingModulus(loadingModulus);
    setUnloadingModulusMax(unloadingModulusMax);
    setCohesionModulus(cohesionModulus);
    setPenetrationDepthMax(penetrationDepthMax);
}

References ERROR, logger, setCohesionModulus(), setLoadingModulus(), setPenetrationDepthMax(), and setUnloadingModulusMax().

setSinterRate()

void HertzianSinterNormalSpecies::setSinterRate

(

Mdouble

sinterRate

)

Sets the linear dissipation coefficient of the linear plastic-viscoelastic normal force.

should be non-negative

Parameters

[in]

the

linear dissipation coefficient of the linear plastic-viscoelastic normal force.

{
    if (sinterRate >= 0)
    {
        sinterRate_ = sinterRate;
    }
    else
    {
        logger(ERROR, "setSinterRate(%) argument has to be non-negative", sinterRate);
    }
}

References ERROR, logger, and sinterRate_.

setUnloadingModulusMax()

void HertzianSinterNormalSpecies::setUnloadingModulusMax

(

Mdouble

unloadingModulusMax

)

Sets the maximum unloading stiffness of the linear plastic-viscoelastic normal force.

Parameters

[in]

unloadingModulusMax

the maximum unloading stiffness of the linear plastic-viscoelastic normal force.

{
    unloadingModulusMax_ = unloadingModulusMax;
}

References unloadingModulusMax_.

Referenced by setPlasticParameters().

write()

void HertzianSinterNormalSpecies::write

(

std::ostream &

os

)

const

Writes the species properties to an output stream.

Parameters

[out]

output

stream (typically the restart file)

{
    os << " loadingModulus " << loadingModulus_;
    os << " maxUnloadingModulus " << unloadingModulusMax_;
    os << " cohesionModulus " << cohesionModulus_;
    os << " maxPenetration " << penetrationDepthMax_;
    os << " dissipation " << dissipation_;
    os << " sinterRate " << sinterRate_;
}

References cohesionModulus_, dissipation_, loadingModulus_, penetrationDepthMax_, sinterRate_, and unloadingModulusMax_.

Member Data Documentation

cohesionModulus_

Mdouble HertzianSinterNormalSpecies::cohesionModulus_

private

the adhesive spring constant (k^c) for plastic deformations

Referenced by getCohesionModulus(), HertzianSinterNormalSpecies(), mix(), read(), setCohesionModulus(), and write().

dissipation_

Mdouble HertzianSinterNormalSpecies::dissipation_

private

linear dissipation coefficient

Referenced by getDissipation(), HertzianSinterNormalSpecies(), mix(), read(), setDissipation(), and write().

loadingModulus_

Mdouble HertzianSinterNormalSpecies::loadingModulus_

private

(normal) spring constant (k_1)

Referenced by getLoadingModulus(), HertzianSinterNormalSpecies(), mix(), read(), setLoadingModulus(), and write().

penetrationDepthMax_

Mdouble HertzianSinterNormalSpecies::penetrationDepthMax_

private

the depth (relative to the normalized radius) at which k_2^max is used (phi_f)

Referenced by getPenetrationDepthMax(), HertzianSinterNormalSpecies(), mix(), read(), setPenetrationDepthMax(), and write().

sinterRate_

Mdouble HertzianSinterNormalSpecies::sinterRate_

private

Referenced by getSinterRate(), HertzianSinterNormalSpecies(), mix(), read(), setSinterRate(), and write().

unloadingModulusMax_

Mdouble HertzianSinterNormalSpecies::unloadingModulusMax_

private

the maximum elastic constant (k_2^max) for plastic deformations

Referenced by getUnloadingModulusMax(), HertzianSinterNormalSpecies(), mix(), read(), setUnloadingModulusMax(), and write().

---

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

• HertzianSinterNormalSpecies.h
• HertzianSinterNormalSpecies.cc