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HertzianViscoelasticInteraction Class Reference

Computes normal forces for a Herztian visco-elastic interaction. More...

#include <HertzianViscoelasticInteraction.h>

Inheritance diagram for HertzianViscoelasticInteraction:

## Public Types

typedef
HertzianViscoelasticNormalSpecies
SpeciesType
An alias for HertzianViscoelasticNormalSpecies. More...

## Public Member Functions

HertzianViscoelasticInteraction (BaseInteractable *P, BaseInteractable *I, Mdouble timeStamp)
Constructor. More...

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

virtual ~HertzianViscoelasticInteraction ()
Destructor. More...

void computeNormalForce ()
Computes the amount of normal force due to an Herztian visco-elastic interaction. More...

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

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

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
HertzianViscoelasticNormalSpecies
getSpecies () const
Returns a const pointer of type HerztianViscoelasticNormalSpecies (dynamic-cast). More...

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...

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

InteractionHandlergetHandler () const
Gets a point to the interaction handlers to which this interaction belongs. More...

const Vec3DgetForce () const
Gets the current force (vector) between the two interacting objects. More...

const Vec3DgetTorque () const
Gets the current torque (vector) between the two interacting objects. More...

const Vec3DgetNormal () const
Gets the normal vector between the two interacting objects. More...

const Vec3DgetContactPoint () 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...

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 ()

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

BaseInteractablegetI ()

const BaseInteractablegetP () const

const BaseInteractablegetI () 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 Vec3DgetRelativeVelocity () 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 BaseInteractioncopy () const =0
Makes a copy of the interaction and returns a pointer to the copy. More...

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...

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...

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

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

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

add an force increment to the total force. More...

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

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

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 for a Herztian visco-elastic interaction.

Definition at line 36 of file HertzianViscoelasticInteraction.h.

## Member Typedef Documentation

An alias for HertzianViscoelasticNormalSpecies.

Definition at line 42 of file HertzianViscoelasticInteraction.h.

## Constructor & Destructor Documentation

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

Constructor.

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

Definition at line 38 of file HertzianViscoelasticInteraction.cc.

39  : BaseInteraction(P, I, timeStamp)
40 {
41 #ifdef DEBUG_CONSTRUCTOR
42  std::cout<<"HertzianViscoelasticInteraction::HertzianViscoelasticInteraction() finished"<<std::endl;
43 #endif
44 }
BaseInteraction(BaseInteractable *P, BaseInteractable *I, Mdouble timeStamp)
A constructor takes the BaseInteractable objects which are interacting (come into contact) and time t...
 HertzianViscoelasticInteraction::HertzianViscoelasticInteraction ( const HertzianViscoelasticInteraction & p )

Copy constructor.

Parameters
 [in] p

Definition at line 48 of file HertzianViscoelasticInteraction.cc.

49  : BaseInteraction(p)
50 {
51 #ifdef DEBUG_CONSTRUCTOR
52  std::cout<<"HertzianViscoelasticInteraction::HertzianViscoelasticInteraction(const HertzianViscoelasticInteraction& p) finished"<<std::endl;
53 #endif
54 }
BaseInteraction(BaseInteractable *P, BaseInteractable *I, Mdouble timeStamp)
A constructor takes the BaseInteractable objects which are interacting (come into contact) and time t...
 HertzianViscoelasticInteraction::~HertzianViscoelasticInteraction ( )
virtual

Destructor.

Definition at line 58 of file HertzianViscoelasticInteraction.cc.

59 {
60 #ifdef DEBUG_DESTRUCTOR
61  std::cout<<"HertzianViscoelasticInteraction::~HertzianViscoelasticInteraction() finished"<<std::endl;
62 #endif
63 }

## Member Function Documentation

 void HertzianViscoelasticInteraction::computeNormalForce ( )

Computes the amount of normal force due to an Herztian visco-elastic interaction.

Todo:
TWnow
Todo:

Definition at line 89 of file HertzianViscoelasticInteraction.cc.

90 {
92  // Compute the relative velocity vector of particle P w.r.t. I
93  setRelativeVelocity(getP()->getVelocityAtContact(getContactPoint()) - getI()->getVelocityAtContact(getContactPoint()));
94  // Compute the projection of vrel onto the normal (can be negative)
96
97  if (getOverlap() > 0) //if contact forces
98  {
100
101  Mdouble stiffness = 4. / 3. * species->getElasticModulus() * std::sqrt(getEffectiveRadius() * getOverlap());
102
103  //calculating the current normal force
104  //dissipation is computed such that the restitution is constant
105  Mdouble normalForce = stiffness * getOverlap() - species->getDissipation() * getNormalRelativeVelocity();
106
107  //setting the normal force parameter in the base interaction class so that it can be accessed
108  //by other classes...
109  setAbsoluteNormalForce(std::abs(normalForce)); //used for further force calculations;
110  setForce(getNormal() * normalForce);
112  setTorque(Vec3D(0.0, 0.0, 0.0));
113  }
114  else
115  {
117  setForce(Vec3D(0.0, 0.0, 0.0));
118  setTorque(Vec3D(0.0, 0.0, 0.0));
119  }
120 }
Returns a Mdouble to the effective radius of the interaction. (Not corrected for the overlap) ...
const HertzianViscoelasticNormalSpecies * getSpecies() const
Returns a const pointer of type HerztianViscoelasticNormalSpecies (dynamic-cast). ...
Mdouble getElasticModulus() const
Allows the spring constant to be accessed.
const Vec3D & getRelativeVelocity() const
Returns a constant reference to a vector of relative velocity.
double Mdouble
void setRelativeVelocity(Vec3D relativeVelocity)
set the relative velocity of the current of the interactions.
void setForce(Vec3D force)
set total force (this is used by the normal force, tangential forces are added use addForce) ...
static Mdouble dot(const Vec3D &a, const Vec3D &b)
Calculates the dot product of two Vec3D: .
Definition: Vector.cc:187
void setNormalRelativeVelocity(Mdouble normalRelativeVelocit)
set the normal component of the relative velocity.
const Vec3D & getContactPoint() const
Gets constant reference to contact point (vector).
Mdouble getNormalRelativeVelocity() const
Returns a double which is the norm (length) of the relative velocity vector.
Mdouble getDissipation() const
Allows the normal dissipation to be accessed.
const Vec3D & getNormal() const
Gets the normal vector between the two interacting objects.
void setTorque(Vec3D torque)
set the total force (this is used by the normal force, tangential torques are added use addTorque) ...
Mdouble getOverlap() const
Returns a Mdouble with the current overlap between the two interacting objects.
void setAbsoluteNormalForce(Mdouble absoluteNormalForce)
the absolute values of the norm (length) of the normal force
BaseInteractable * getI()
BaseInteractable * getP()
Returns a pointer to first object involved in the interaction (normally a particle).
Implementation of a 3D vector (by Vitaliy).
Definition: Vector.h:45
HertzianViscoelasticNormalSpecies contains the parameters used to describe a Hertzian normal force (T...
 std::string HertzianViscoelasticInteraction::getBaseName ( ) const

Returns the name of the interaction.

Returns
std::string

Definition at line 82 of file HertzianViscoelasticInteraction.cc.

83 {
84  return "HertzianViscoelastic";
85 }
 Mdouble HertzianViscoelasticInteraction::getElasticEnergy ( ) const
virtual

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

Returns
Mdouble
Todo:
TW This is not correct

Reimplemented from BaseInteraction.

Definition at line 124 of file HertzianViscoelasticInteraction.cc.

125 {
126  if (getOverlap() > 0)
127  return 0.5 * (getSpecies()->getElasticModulus() * mathsFunc::square(getOverlap()));
128  else
129  return 0.0;
131 }
const HertzianViscoelasticNormalSpecies * getSpecies() const
Returns a const pointer of type HerztianViscoelasticNormalSpecies (dynamic-cast). ...
Mdouble getElasticModulus() const
Allows the spring constant to be accessed.
T square(T val)
squares a number
Definition: ExtendedMath.h:91
Mdouble getOverlap() const
Returns a Mdouble with the current overlap between the two interacting objects.
 const HertzianViscoelasticNormalSpecies * HertzianViscoelasticInteraction::getSpecies ( ) const

Returns a const pointer of type HerztianViscoelasticNormalSpecies (dynamic-cast).

Returns
const HertzianViscoelasticNormalSpecies*

Definition at line 135 of file HertzianViscoelasticInteraction.cc.

References BaseInteraction::getBaseSpecies().

Referenced by computeNormalForce(), and getElasticEnergy().

136 {
137  return dynamic_cast<const HertzianViscoelasticNormalSpecies*>(getBaseSpecies());
138 }
const BaseSpecies * getBaseSpecies() const
Return a constant point to BaseSpecies of the interaction.
HertzianViscoelasticNormalSpecies contains the parameters used to describe a Hertzian normal force (T...
 void HertzianViscoelasticInteraction::read ( std::istream & is )
virtual

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

Parameters
 [in,out] is

Reimplemented from BaseInteraction.

Definition at line 75 of file HertzianViscoelasticInteraction.cc.

76 {
78 }
Interaction read function, which accepts an std::istream as input.
 void HertzianViscoelasticInteraction::write ( std::ostream & os ) const
virtual

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

Parameters
 [in,out] os

Reimplemented from BaseInteraction.

Definition at line 68 of file HertzianViscoelasticInteraction.cc.

References BaseInteraction::write().

69  {
71 }
virtual void write(std::ostream &os) const
Interaction print function, which accepts an std::ostream as input.

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