Computes normal forces in case of a linear plastic visco-elastic interaction. More...

#include <HertzianSinterInteraction.h>

Inheritance diagram for HertzianSinterInteraction:

Public Member Functions
	HertzianSinterInteraction (BaseInteractable P, BaseInteractable I, Mdouble timeStamp)
	Constructor. More...

	HertzianSinterInteraction (const HertzianSinterInteraction &p)
	Copy constructor. More...

virtual	~HertzianSinterInteraction ()
	Destructor. More...

void	computeSinterForce ()
	Creates a copy of an object of this class. (Deep copy) More...

void	computeNormalForce ()
	Calls computeSinterForce(). More...

virtual void	read (std::istream &is)
	Interaction read function, which accepts an std::istream as input. More...

virtual void	write (std::ostream &os) const
	Interaction write function, which accepts an std::ostream as input. More...

virtual std::string	getBaseName () const
	Returns the name of the interaction. More...

Mdouble	getElasticEnergy () const
	Computes and returns the amount of elastic energy stored in the spring. More...

const HertzianSinterNormalSpecies *	getSpecies () const

Mdouble	getMaxOverlap () const

void	setMaxOverlap (const Mdouble)

Mdouble	getUnloadingModulus () const

Public Member Functions inherited from BaseInteraction
	BaseInteraction (BaseInteractable P, BaseInteractable I, Mdouble timeStamp)
	A constructor takes the BaseInteractable objects which are interacting (come into contact) and time the interaction starts. More...

	BaseInteraction (const BaseInteraction &p)
	Copy constructor. More...

	BaseInteraction ()
	Empty constructor. More...

virtual	~BaseInteraction ()
	The default destructor. More...

virtual void	actionsOnErase ()
	If an interaction needs to do something before it gets erased, add it here. E.g. Liquid bridges rupture at the end of their lifetime, and the liquid bridge volume has to be redistributed. The reason this action is not done in the destructor is that this action should not be taken when erasing ghost interactions. More...

virtual void	computeForce ()
	Virtual function that contains the force law between the two objects interacting. More...

void	writeToFStat (std::ostream &os) const
	Writes forces data to the FStat file. More...

virtual std::string	getName () const
	Virtual function which allows interactions to be named. More...

void	setDistance (Mdouble distance)
	Sets the interaction distance between the two interacting objects. More...

void	setNormal (Vec3D normal)
	Sets the normal vector between the two interacting objects. More...

void	setOverlap (Mdouble overlap)
	Set the overlap between the two interacting object. More...

void	setContactPoint (Vec3D contactPoint)
	Set the location of the contact point between the two interacting objects. More...

void	setTimeStamp (Mdouble timeStamp)
	Updates the time step of the interacting. Note, timesteps used to find completed interactions. More...

void	setSpecies (BaseSpecies *species)
	Set the Species of the interaction; note this can either be a Species or MixedSpecies. More...

void	setP (BaseInteractable *P)
	Sets the first object involved in the interaction (normally a particle). More...

void	setI (BaseInteractable *I)
	Sets the second object involved in the interaction (often particle or wall). More...

void	setHandler (InteractionHandler *handler)
	Sets the pointer to the interaction hander which is storing this interaction. More...

InteractionHandler *	getHandler () const
	Gets a point to the interaction handlers to which this interaction belongs. More...

const Vec3D &	getForce () const
	Gets the current force (vector) between the two interacting objects. More...

const Vec3D &	getTorque () const
	Gets the current torque (vector) between the two interacting objects. More...

const Vec3D &	getNormal () const
	Gets the normal vector between the two interacting objects. More...

const Vec3D &	getContactPoint () const
	Gets constant reference to contact point (vector). More...

Mdouble	getOverlap () const
	Returns a Mdouble with the current overlap between the two interacting objects. More...

Mdouble	getContactRadius () const
	Returns a Mdouble with the current contact between the two interacting objects. More...

void	removeFromHandler ()
	Removes this interaction from its interaction hander. More...

void	copySwitchPointer (const BaseInteractable original, BaseInteractable ghost) const
	This copies the interactions of the original particle and replaces the original with the ghost copy. More...

void	gatherContactStatistics ()

BaseInteractable *	getP ()
	Returns a pointer to first object involved in the interaction (normally a particle). More...

BaseInteractable *	getI ()

const BaseInteractable *	getP () const

const BaseInteractable *	getI () const
	Returns a constant pointer to the second object involved in the interaction. More...

Mdouble	getTimeStamp () const
	Returns an Mdouble which is the time stamp of the interaction. More...

virtual void	integrate (Mdouble timeStep)
	integrates variables of the interaction which need to be integrate e.g. the tangential overlap. More...

virtual Mdouble	getTangentialOverlap () const
	get the length of the current tangential overlap More...

Mdouble	getDistance () const
	Returns an Mdouble which is the norm (length) of distance vector. More...

const Vec3D &	getRelativeVelocity () const
	Returns a constant reference to a vector of relative velocity. More...

Mdouble	getNormalRelativeVelocity () const
	Returns a double which is the norm (length) of the relative velocity vector. More...

Mdouble	getAbsoluteNormalForce () const
	Returns the absolute value of the norm (length) of the Normal force vector. More...

virtual BaseInteraction *	copy () const =0
	Makes a copy of the interaction and returns a pointer to the copy. More...

unsigned int	getMultiContactIdentifier () const

void	setMultiContactIdentifier (unsigned int multiContactIdentifier_)

virtual void	rotateHistory (Matrix3D &rotationMatrix)
	When periodic particles are used, some interactions need certain history properties rotated (e.g. tangential springs). This is the function for that. More...

virtual void	actionsAfterTimeStep ()

virtual unsigned	getNumberOfFieldsVTK () const

virtual std::string	getTypeVTK (unsigned i) const

virtual std::string	getNameVTK (unsigned i) const

virtual std::vector< Mdouble >	getFieldVTK (unsigned i) const

void	setForce (Vec3D force)
	set total force (this is used by the normal force, tangential forces are added use addForce) More...

Public Member Functions inherited from BaseObject
	BaseObject ()
	Default constructor. More...

	BaseObject (const BaseObject &p)
	Copy constructor, copies all the objects BaseObject contains. More...

virtual	~BaseObject ()
	virtual destructor More...

virtual void	moveInHandler (const unsigned int index)
	Except that it is virtual, it does the same thing as setIndex() does. More...

void	setIndex (const unsigned int index)
	Allows one to assign an index to an object in the handler/container. More...

void	setId (const unsigned int id)
	Assigns a unique identifier to each object in the handler (container) which remains constant even after the object is deleted from the container/handler. More...

unsigned int	getIndex () const
	Returns the index of the object in the handler. More...

unsigned int	getId () const
	Returns the unique identifier of any particular object. More...

Private Attributes
Mdouble	maxOverlap_

Additional Inherited Members
Protected Member Functions inherited from BaseInteraction
virtual const Vec3D	getTangentialForce () const

Mdouble	getEffectiveRadius () const
	Returns a Mdouble to the effective radius of the interaction. (Not corrected for the overlap) More...

Mdouble	getEffectiveMass () const
	Returns a Mdouble to the effective radius of the interaction. (Not corrected for the overlap) More...

Mdouble	getEffectiveCorrectedRadius ()
	Returns a Mdouble to the effective radius corrected for the overlaps of the particles. More...

void	addForce (Vec3D force)
	add an force increment to the total force. More...

void	addTorque (Vec3D torque)

void	setTorque (Vec3D torque)
	set the total force (this is used by the normal force, tangential torques are added use addTorque) More...

void	setRelativeVelocity (Vec3D relativeVelocity)
	set the relative velocity of the current of the interactions. More...

void	setNormalRelativeVelocity (Mdouble normalRelativeVelocit)
	set the normal component of the relative velocity. More...

void	setAbsoluteNormalForce (Mdouble absoluteNormalForce)
	the absolute values of the norm (length) of the normal force More...

const BaseSpecies *	getBaseSpecies () const
	Return a constant point to BaseSpecies of the interaction. More...

virtual Mdouble	getElasticEnergyAtEquilibrium (Mdouble adhesiveForce) const

virtual void	reverseHistory ()
	When periodic particles some interaction need certain history properties reversing. This is the function for that. More...

Detailed Description

Computes normal forces in case of a linear plastic visco-elastic interaction.

Definition at line 36 of file HertzianSinterInteraction.h.

Constructor & Destructor Documentation

HertzianSinterInteraction::HertzianSinterInteraction	(	BaseInteractable *	P,
		BaseInteractable *	I,
		Mdouble	timeStamp
	)

Constructor.

Parameters

[in]	P
[in]	I
[in]	timeStamp

Definition at line 41 of file HertzianSinterInteraction.cc.

References maxOverlap_.

         : BaseInteraction(P, I, timeStamp)
 {
     maxOverlap_=0;
 #ifdef DEBUG_CONSTRUCTOR
     std::cout<<"HertzianSinterInteraction::HertzianSinterInteraction() finished"<<std::endl;
 #endif
 }

HertzianSinterInteraction::HertzianSinterInteraction ( const HertzianSinterInteraction & p )

Copy constructor.

Parameters

[in] p

Definition at line 52 of file HertzianSinterInteraction.cc.

References maxOverlap_.

         : BaseInteraction(p)
 {
     maxOverlap_=p.maxOverlap_;
 #ifdef DEBUG_CONSTRUCTOR
     std::cout<<"HertzianSinterInteraction::HertzianSinterInteraction(const HertzianSinterInteraction &p finished"<<std::endl;
 #endif
 }

HertzianSinterInteraction::~HertzianSinterInteraction ( )

virtual

Destructor.

Definition at line 63 of file HertzianSinterInteraction.cc.

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

Member Function Documentation

void HertzianSinterInteraction::computeNormalForce ( )

Calls computeSinterForce().

Definition at line 175 of file HertzianSinterInteraction.cc.

References computeSinterForce().

 {
     computeSinterForce();
 }

void HertzianSinterInteraction::computeSinterForce ( )

Creates a copy of an object of this class. (Deep copy)

Computes the normal forces due to linear plastic visco elastic interaction.

Definition at line 99 of file HertzianSinterInteraction.cc.

Referenced by computeNormalForce().

 {
     // Compute the relative velocity vector of particle P w.r.t. I
     setRelativeVelocity(getP()->getVelocityAtContact(getContactPoint()) - getI()->getVelocityAtContact(getContactPoint()));
     // Compute the projection of vrel onto the normal (can be negative)
     setNormalRelativeVelocity(Vec3D::dot(getRelativeVelocity(), getNormal()));
 
     if (getOverlap() > 0) //if contact forces
     {
         const HertzianSinterNormalSpecies* species = getSpecies();
         Mdouble effectiveDiameter = 2.0*getEffectiveRadius();
 
         //calculate the overlap above which the max. unloading stiffness becomes active (the 'fluid branch')
         static Mdouble maxFactor = 1
             -mathsFunc::square(cbrt((species->getLoadingModulus()+species->getCohesionModulus())/species->getUnloadingModulusMax()));
         Mdouble deltaStar = species->getPenetrationDepthMax() * effectiveDiameter/maxFactor;
     
         //increase max overlap if necessary
         if (getOverlap()>getMaxOverlap()) {
             setMaxOverlap(getOverlap());
             std::cout << "," << getHandler()->getDPMBase()->getTime();
         }
         //limit max overlap if necessary
         if (getMaxOverlap()>deltaStar)
             setMaxOverlap(deltaStar);
             
         //calculate the unloading modulus
         Mdouble loadingCohesionModulus = species->getLoadingModulus()+species->getCohesionModulus();
         Mdouble unloadingModulus = loadingCohesionModulus
             + (species->getUnloadingModulusMax() - loadingCohesionModulus) * (getMaxOverlap() / deltaStar);
             
         //calculate the overlap where the force is minimal
         Mdouble factor = 1-mathsFunc::square(cbrt(loadingCohesionModulus/unloadingModulus));
         Mdouble minOverlap = factor*maxOverlap_;
 
         //add dissipative force
         Mdouble normalForce = -species->getDissipation() * getNormalRelativeVelocity();
 
         //compute elastic force
         if (getOverlap() < minOverlap) {
             //decrease max overlap if in cohesive range
             std::cout << "." << getHandler()->getDPMBase()->getTime();
             setMaxOverlap(getOverlap()/factor);
         } else {
             Mdouble contactRadius = sqrt(2.0*effectiveDiameter * (getOverlap()-minOverlap));
             normalForce += 4./3.*unloadingModulus * contactRadius *(getOverlap()-minOverlap);
         }
                    
         setAbsoluteNormalForce(std::abs(normalForce)); //used for the friction force calculations;
         
         Mdouble contactRadius = sqrt(2.0*effectiveDiameter * getOverlap());
         normalForce -= 4./3.*species->getCohesionModulus() * contactRadius *getOverlap();
             
         setForce(getNormal() * normalForce);
         setTorque(Vec3D(0.0, 0.0, 0.0));
         
         //now add the sintering model 'modified Frenkel' of the Pokula paper
         //plasticOverlap_+=species->getSinterRate()*(deltaStar-plasticOverlap_)*getHandler()->getDPMBase()->getTimeStep();
         //x/a=sqrt(2*a*del)/a
         Mdouble x = 1e-10+sqrt(2.0*maxOverlap_/effectiveDiameter);
         //Mdouble x2 = x*x;
         Mdouble dx = 0.5/x;//+ x*(-0.5 + x2* (0.15625 + x2*(-0.0208333 +x2*(-0.00325521  +x2*(0.000189887 +x2*0.0000542535)))));
         Mdouble doverlap = x*dx*effectiveDiameter;
         //doverlap = 0.5/(factor*factor*plasticOverlap_);
         maxOverlap_ += species->getSinterRate()*doverlap*getHandler()->getDPMBase()->getTimeStep();
     }
     else
     {
         setAbsoluteNormalForce(0.0);
         setForce(Vec3D(0.0, 0.0, 0.0));
         setTorque(Vec3D(0.0, 0.0, 0.0));
     } 
 }

std::string HertzianSinterInteraction::getBaseName ( ) const

virtual

Returns the name of the interaction.

Returns: std::string

Definition at line 92 of file HertzianSinterInteraction.cc.

 {
     return "HertzianSinter";
 }

Mdouble HertzianSinterInteraction::getElasticEnergy ( ) const

virtual

Computes and returns the amount of elastic energy stored in the spring.

Returns: Mdouble

Todo:: TW this is not correct; we should count the return energy

Reimplemented from BaseInteraction.

Definition at line 182 of file HertzianSinterInteraction.cc.

References HertzianSinterNormalSpecies::getLoadingModulus(), BaseInteraction::getOverlap(), getSpecies(), and mathsFunc::square().

 {
    if (getOverlap() > 0)
         return 0.5 * (getSpecies()->getLoadingModulus() * mathsFunc::square(getOverlap()));
     else
         return 0.0;
 }

Mdouble HertzianSinterInteraction::getMaxOverlap ( ) const

Returns: Mdouble plasticOverlap_

Definition at line 200 of file HertzianSinterInteraction.cc.

References maxOverlap_.

Referenced by computeSinterForce(), and getUnloadingModulus().

 {
     return maxOverlap_;
 }

const HertzianSinterNormalSpecies * HertzianSinterInteraction::getSpecies ( ) const

Returns: const HertzianSinterNormalSpecies*

Definition at line 193 of file HertzianSinterInteraction.cc.

References BaseInteraction::getBaseSpecies().

Referenced by computeSinterForce(), getElasticEnergy(), and getUnloadingModulus().

 {
     return dynamic_cast<const HertzianSinterNormalSpecies*>(getBaseSpecies());
 }

Mdouble HertzianSinterInteraction::getUnloadingModulus ( ) const

Returns: Mdouble

Definition at line 214 of file HertzianSinterInteraction.cc.

References BaseInteraction::getEffectiveRadius(), HertzianSinterNormalSpecies::getLoadingModulus(), getMaxOverlap(), BaseInteraction::getOverlap(), HertzianSinterNormalSpecies::getPenetrationDepthMax(), getSpecies(), and HertzianSinterNormalSpecies::getUnloadingModulusMax().

 {
     const HertzianSinterNormalSpecies* species = getSpecies();
     Mdouble effectiveDiameter = 2.0*getEffectiveRadius();
     Mdouble deltaMaxFluid = species->getPenetrationDepthMax() * effectiveDiameter / (1.0-species->getLoadingModulus()/species->getUnloadingModulusMax());
     if (getOverlap() > deltaMaxFluid)
         return species->getUnloadingModulusMax();
     else
         return species->getLoadingModulus() + (species->getUnloadingModulusMax() - species->getLoadingModulus()) * getMaxOverlap()/deltaMaxFluid;
 }

void HertzianSinterInteraction::read ( std::istream & is )

virtual

Interaction read function, which accepts an std::istream as input.

Calls the read function of BaseInteraction().

Parameters

[in,out] is

Reimplemented from BaseInteraction.

Definition at line 83 of file HertzianSinterInteraction.cc.

References maxOverlap_, and BaseInteraction::read().

 {
     BaseInteraction::read(is);
     std::string dummy;
     is >> dummy >> maxOverlap_;
 }

void HertzianSinterInteraction::setMaxOverlap ( const Mdouble maxOverlap )

Parameters

[in] maxOverlap

Definition at line 207 of file HertzianSinterInteraction.cc.

References maxOverlap_.

Referenced by computeSinterForce().

 {
     maxOverlap_ = maxOverlap;
 }

void HertzianSinterInteraction::write ( std::ostream & os ) const

virtual

Interaction write function, which accepts an std::ostream as input.

Calls the write function of BaseInteraction().

Parameters

[in,out] os

Reimplemented from BaseInteraction.

Definition at line 74 of file HertzianSinterInteraction.cc.

References maxOverlap_, and BaseInteraction::write().

 {
     BaseInteraction::write(os);
     os << " maxOverlap " << maxOverlap_;
 }

Member Data Documentation

Mdouble HertzianSinterInteraction::maxOverlap_

private

Definition at line 99 of file HertzianSinterInteraction.h.

Referenced by computeSinterForce(), getMaxOverlap(), HertzianSinterInteraction(), read(), setMaxOverlap(), and write().

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

Interactions/NormalForceInteractions/HertzianSinterInteraction.h
Interactions/NormalForceInteractions/HertzianSinterInteraction.cc

Public Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation