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FrictionInteraction Class Reference

This class allows one to take all three types of frictional interactions into account. The sliding, rolling and torsional frictional interaction. See. More...

#include <FrictionInteraction.h>

+ Inheritance diagram for FrictionInteraction:

Public Types

typedef FrictionSpecies SpeciesType
 An alias for FrictionSpecies. More...
 
- Public Types inherited from SlidingFrictionInteraction
typedef SlidingFrictionSpecies SpeciesType
 An alias name for SlidingFrictionSpecies data type. More...
 

Public Member Functions

 FrictionInteraction (BaseInteractable *P, BaseInteractable *I, unsigned timeStamp)
 Constructor. More...
 
 FrictionInteraction ()
 
 FrictionInteraction (const FrictionInteraction &p)
 Copy constructor. More...
 
 ~FrictionInteraction () override
 Destructor. More...
 
void computeFrictionForce ()
 Computes the forces arising due to all three types of friction, i.e., sliding, rolling and torsional. More...
 
void read (std::istream &is) override
 Interaction read function, which accepts an std::istream as input. More...
 
void write (std::ostream &os) const override
 Interaction print function, which accepts an std::ostream as input. More...
 
void integrate (Mdouble timeStep) override
 Computes the amount of compression in all the springs, i.e., increments the rollingSpring_, slidingSpring_ (see SlidingFrictionInteraction.cc) and torsionSpring_. More...
 
Mdouble getElasticEnergy () const override
 Returns the global amount of energy stored in all the springs (rolling, sliding and torsional). More...
 
std::string getBaseName () const
 Returns interaction name/type. More...
 
const FrictionSpeciesgetSpecies () const
 Returns a const pointer of type FrictionSpecies*. More...
 
void reverseHistory () override
 A useful feature if one wants to return to the initial state of the springs. However, reverse history decrements the current state to the state corresponding to previous time step. Decrements the state or value of rollingSpring_, torsionSpring_ and slidingSpring_. More...
 
void rotateHistory (Matrix3D &rotationMatrix) override
 When periodic particles are used, some interactions need certain history properties rotated (e.g. tangential springs). This is the function for that. More...
 
Vec3D getRollingSpring () const
 
Vec3D getTorsionSpring () const
 
void setRollingSpring (Vec3D rollingSpring)
 
void setTorsionSpring (Vec3D torsionSpring)
 
- Public Member Functions inherited from SlidingFrictionInteraction
 SlidingFrictionInteraction (BaseInteractable *P, BaseInteractable *I, unsigned timeStamp)
 Constructor. More...
 
 SlidingFrictionInteraction ()
 
 SlidingFrictionInteraction (const SlidingFrictionInteraction &p)
 Copy constructor. More...
 
 ~SlidingFrictionInteraction () override
 Destructor. More...
 
void computeFrictionForce ()
 Computes the tangential force generated due to compression in the sliding spring. Does take into account if the interaction is between particle-particle or particle-wall. More...
 
void read (std::istream &is) override
 Interaction read function, which accepts an std::istream as input. More...
 
void write (std::ostream &os) const override
 Interaction write function, which accepts an std::ostream as input. More...
 
void integrate (Mdouble timeStep) override
 Increments the amount of compression in sliding spring. More...
 
Mdouble getElasticEnergy () const override
 Returns the amount of elastic energy stored in sliding spring. More...
 
Mdouble getTangentialOverlap () const override
 Returns the amount of tangential overlap which is needed by BaseInteraction::writeToFstat(). More...
 
std::string getBaseName () const
 Returns the type/name of interaction (sliding friction interaction) More...
 
void setSlidingSpring (Vec3D slidingSpring)
 
Vec3D getSlidingSpring () const
 
const Vec3D getTangentialForce () const override
 Returns the sliding friction force vector. More...
 
const SlidingFrictionSpeciesgetSpecies () const
 Returns a const pointer of type SlidingFrictionSpecies*. More...
 
void reverseHistory () override
 A useful feature if one wants to return to the initial state of the spring. However, reverse history decrements the current state to the state corresponding to previous time step. Decrements the value of slidingSpring_. More...
 
void rotateHistory (Matrix3D &rotationMatrix) override
 When periodic particles are used, some interactions need certain history properties rotated (e.g. tangential springs). This is the function for that. More...
 
void moveSlidingSpring (Vec3D displacement)
 
void computeSlidingSpring (const Vec3D &tangentialRelativeVelocity)
 
void computeSlidingSpringSuperQuadric (const Vec3D &tangentialRelativeVelocity)
 
void setIsSuperQuadricInteraction (bool isSuperQuadricInteraction)
 
- Public Member Functions inherited from BaseInteraction
 BaseInteraction (BaseInteractable *P, BaseInteractable *I, unsigned timeStamp)
 A constructor takes the BaseInteractable objects which are interacting (come into contact) and time the interaction starts. More...
 
 BaseInteraction ()
 
 BaseInteraction (const BaseInteraction &p)
 Copy constructor. More...
 
 ~BaseInteraction () override
 The 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, Mdouble time) const
 Writes forces data to the FStat file. More...
 
std::string getName () const override
 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 (unsigned timeStamp)
 Updates the time step of the interacting. Note, time steps used to find completed interactions. More...
 
void setSpecies (const 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 importP (BaseInteractable *P)
 Sets the first object involved in the interaction (normally a particle). More...
 
void importI (BaseInteractable *I)
 Sets the second object involved in the interaction (often particle or wall). More...
 
Vec3D getIP () const
 
Vec3D getIC () const
 
Vec3D getCP () const
 
void setLagrangeMultiplier (Mdouble multiplier)
 
Mdouble getLagrangeMultiplier ()
 
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...
 
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 ()
 
BaseInteractablegetP ()
 Returns a pointer to first object involved in the interaction (normally a particle). More...
 
BaseInteractablegetI ()
 Returns a pointer to the second object involved in the interaction (often a wall or a particle). More...
 
const BaseInteractablegetP () const
 Returns a constant pointer to the first object involved in the interaction. More...
 
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...
 
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...
 
void setFStatData (std::fstream &fstat, BaseParticle *P, BaseWall *I)
 
void setFStatData (std::fstream &fstat, BaseParticle *P, BaseParticle *I)
 
unsigned int getMultiContactIdentifier () const
 
void setMultiContactIdentifier (unsigned int multiContactIdentifier_)
 
virtual void actionsAfterTimeStep ()
 
virtual unsigned getNumberOfFieldsVTK () const
 
virtual std::string getTypeVTK (unsigned i) const
 
virtual std::string getNameVTK (unsigned i) const
 
virtual std::vector< MdoublegetFieldVTK (unsigned i) const
 
void setForce (Vec3D force)
 set total force (this is used by the normal force, tangential forces are added use addForce) More...
 
const BaseSpeciesgetBaseSpecies () const
 Return a constant point to BaseSpecies of the interaction. More...
 
virtual void createMPIType ()
 
virtual void * createMPIInteractionDataArray (unsigned int numberOfInteractions) const
 
virtual void deleteMPIInteractionDataArray (void *dataArray)
 
virtual void getMPIInteraction (void *historyDataArray, unsigned int index) const
 copies the history interactions into the data array More...
 
virtual void getInteractionDetails (void *interactionDataArray, unsigned int index, unsigned int &identificationP, unsigned int &identificationI, bool &isWallInteraction, unsigned &timeStamp)
 
virtual void setMPIInteraction (void *interactionDataArray, unsigned int index, bool resetPointers)
 
void setBasicMPIInteractionValues (int P, int I, unsigned timeStamp, Vec3D force, Vec3D torque, bool isWallInteraction, bool resetPointers)
 
void setIdentificationP (unsigned int identification)
 
void setIdentificationI (int identification)
 
void setWallInteraction (bool flag)
 
unsigned int getIdentificationP ()
 
int getIdentificationI ()
 
bool isWallInteraction ()
 
virtual bool isBonded () const
 
- Public Member Functions inherited from BaseObject
 BaseObject ()=default
 Default constructor. More...
 
 BaseObject (const BaseObject &p)=default
 Copy constructor, copies all the objects BaseObject contains. More...
 
virtual ~BaseObject ()=default
 virtual destructor More...
 
virtual void moveInHandler (unsigned int index)
 Except that it is virtual, it does the same thing as setIndex() does. More...
 
void setIndex (unsigned int index)
 Allows one to assign an index to an object in the handler/container. More...
 
void setId (unsigned long 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...
 
void setGroupId (unsigned groupId)
 
unsigned getGroupId () const
 

Private Attributes

Vec3D rollingSpring_
 Stores the amount of rolling spring compression. Set in integrate(), used in computing frictional force due to rolling. More...
 
Vec3D rollingSpringVelocity_
 Stores the rate at which the rolling spring compresses or relaxes. Set in computeFrictionForce(), used in computing the amount of compression in rolling spring. Used in integrate(). More...
 
Vec3D torsionSpring_
 Stores the amount of torsional spring compression. Set in integrate(), used in computing frictional force due to torsion. More...
 
Vec3D torsionSpringVelocity_
 Stores the rate at which the torsional spring compresses or relaxes. Set in computeFrictionForce(), used in computing the amount of compression in torsion spring. Used in integrate(). More...
 

Additional Inherited Members

- Protected Member Functions inherited from BaseInteraction
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...
 
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...
 
virtual Mdouble getElasticEnergyAtEquilibrium (Mdouble adhesiveForce) const
 
void writeInteraction (std::ostream &os, bool created) const
 Writes information about a interaction to the interaction file. More...
 
- Protected Attributes inherited from SlidingFrictionInteraction
Vec3D slidingSpring_
 Stores the amount of sliding spring ( \(\delta\)) compression from the expression \(f_t=-k*\delta-\nu*relVel\). Set in the member function integrate(), used in computeFrictionForce(). More...
 
Vec3D slidingSpringVelocity_
 Stores the rate at which the sliding spring compressed or relaxed. Set in the member function computeFrictionForce() and used in integrate(). More...
 
Vec3D tangentialForce_
 Computes the tangential force such that \(|f_t|=\mu*|f_n|\). Set and computed in computeFrictionForce(). More...
 
bool isSuperQuadricInteraction_
 

Detailed Description

This class allows one to take all three types of frictional interactions into account. The sliding, rolling and torsional frictional interaction. See.

Definition at line 44 of file FrictionInteraction.h.

Member Typedef Documentation

Constructor & Destructor Documentation

FrictionInteraction::FrictionInteraction ( BaseInteractable P,
BaseInteractable I,
unsigned  timeStamp 
)

Constructor.

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

Definition at line 40 of file FrictionInteraction.cc.

References rollingSpring_, Vec3D::setZero(), and torsionSpring_.

41  : BaseInteraction(P, I, timeStamp), SlidingFrictionInteraction(P, I, timeStamp)
42 {
45 #ifdef DEBUG_CONSTRUCTOR
46  std::cout<<"FrictionInteraction::FrictionInteraction() finished"<<std::endl;
47 #endif
48 }
void setZero()
Sets all elements to zero.
Definition: Vector.cc:43
Vec3D torsionSpring_
Stores the amount of torsional spring compression. Set in integrate(), used in computing frictional f...
Vec3D rollingSpring_
Stores the amount of rolling spring compression. Set in integrate(), used in computing frictional for...
FrictionInteraction::FrictionInteraction ( )

Definition at line 51 of file FrictionInteraction.cc.

References rollingSpring_, Vec3D::setZero(), and torsionSpring_.

53 {
56 #ifdef DEBUG_CONSTRUCTOR
57  std::cout<<"FrictionInteraction::FrictionInteraction() finished"<<std::endl;
58 #endif
59 }
void setZero()
Sets all elements to zero.
Definition: Vector.cc:43
Vec3D torsionSpring_
Stores the amount of torsional spring compression. Set in integrate(), used in computing frictional f...
Vec3D rollingSpring_
Stores the amount of rolling spring compression. Set in integrate(), used in computing frictional for...
FrictionInteraction::FrictionInteraction ( const FrictionInteraction p)

Copy constructor.

Parameters
[in]p

Definition at line 64 of file FrictionInteraction.cc.

References rollingSpring_, and torsionSpring_.

66 {
69 #ifdef DEBUG_CONSTRUCTOR
70  std::cout<<"FrictionInteraction::FrictionInteraction(const FrictionInteraction& p) finished"<<std::endl;
71 #endif
72 }
Vec3D torsionSpring_
Stores the amount of torsional spring compression. Set in integrate(), used in computing frictional f...
Vec3D rollingSpring_
Stores the amount of rolling spring compression. Set in integrate(), used in computing frictional for...
FrictionInteraction::~FrictionInteraction ( )
override

Destructor.

Definition at line 77 of file FrictionInteraction.cc.

78 {
79 #ifdef DEBUG_DESTRUCTOR
80  std::cout<<"FrictionInteraction::~FrictionInteraction() finished"<<std::endl;
81 #endif
82 }

Member Function Documentation

void FrictionInteraction::computeFrictionForce ( )

Computes the forces arising due to all three types of friction, i.e., sliding, rolling and torsional.

Calls the slidingFrictionInteraction::computeFrictionForce() as well, see slidingFrictionInteraction.cc.

Todo:
TW: Why do we not use the corrected diameter here, as in the rolling case? And check if Stefan uses radius or diameter

Definition at line 108 of file FrictionInteraction.cc.

References BaseInteraction::addTorque(), SlidingFrictionInteraction::computeFrictionForce(), Vec3D::cross(), Vec3D::dot(), BaseInteraction::getAbsoluteNormalForce(), BaseInteraction::getBaseSpecies(), BaseInteraction::getDistance(), BaseHandler< T >::getDPMBase(), BaseInteraction::getEffectiveMass(), BaseInteraction::getEffectiveRadius(), BaseInteraction::getHandler(), BaseInteraction::getI(), Vec3D::getLengthSquared(), BaseInteraction::getNormal(), BaseInteraction::getP(), FrictionSpecies::getRollingDissipation(), FrictionSpecies::getRollingFrictionCoefficient(), FrictionSpecies::getRollingFrictionCoefficientStatic(), FrictionSpecies::getRollingStiffness(), getSpecies(), DPMBase::getTimeStep(), FrictionSpecies::getTorsionDissipation(), FrictionSpecies::getTorsionFrictionCoefficient(), FrictionSpecies::getTorsionFrictionCoefficientStatic(), FrictionSpecies::getTorsionStiffness(), BaseInteractable::getVelocity(), rollingSpring_, rollingSpringVelocity_, mathsFunc::square(), torsionSpring_, and torsionSpringVelocity_.

109 {
111 
112  const FrictionSpecies* species = getSpecies();
113  //If tangential forces are present
114  if (getAbsoluteNormalForce() == 0.0) return;
115 
116 
117  if (species->getRollingFrictionCoefficient() != 0.0)
118  {
119  if (species->getRollingStiffness() != 0.0)
120  {
121  Mdouble effectiveDiameter = 2.0 * getEffectiveRadius();
122 
123  //From Luding2008, objective rolling velocity (eq 15) w/o 2.0!
124  Vec3D rollingRelativeVelocity = -effectiveDiameter *
126  getP()->getAngularVelocity() - getI()->getAngularVelocity());
127 
128  if (dynamic_cast<BaseParticle*>(getI()) == nullptr) //if particle-wall
129  rollingSpringVelocity_ = rollingRelativeVelocity;
130  else //if particle-particle
131  {
132  const Vec3D relativeVelocity = getP()->getVelocity() - getI()->getVelocity();
133  rollingSpringVelocity_ = rollingRelativeVelocity
134  - Vec3D::dot(rollingSpring_, relativeVelocity) / getDistance() * getNormal();
135  }
136 
137  //used to Integrate the spring
138  //rollingSpringVelocity_= rollingRelativeVelocity;
139  //integrate(getHandler()->timeStep_);
141 
142  //Calculate test force acting on P including viscous force
143  Vec3D rollingForce = -species->getRollingStiffness() * rollingSpring_ -
144  species->getRollingDissipation() * rollingRelativeVelocity;
145  if (getBaseSpecies()->getNormalForce()->getConstantRestitution()) rollingForce *=2.0*getEffectiveMass();
146 
147  //tangential forces are modelled by a spring-damper of elasticity kt and viscosity dispt (sticking),
148  //but the force is limited by Coulomb friction (rolling):
149  Mdouble rollingForceSquared = rollingForce.getLengthSquared();
150  if (rollingForceSquared <=
152  {
153  //if sticking (|ft|<=mu*|fn|), apply the force
154  }
155  else
156  {
157  //if rolling, resize the tangential force such that |ft|=mu*|fn|
158  rollingForce *= species->getRollingFrictionCoefficient() * getAbsoluteNormalForce() /
159  std::sqrt(rollingForceSquared);
160  //resize the tangential spring accordingly such ft=-k*delta-nu*relVel
161  rollingSpring_ = -(rollingForce + species->getRollingDissipation() * rollingRelativeVelocity) /
162  species->getRollingStiffness();
163  }
164  //Add (virtual) rolling force to torque
165  addTorque(effectiveDiameter * Vec3D::cross(getNormal(), rollingForce));
166  }
167  else //if no spring stiffness is set
168  {
169  std::cerr << "FrictionInteraction::computeFrictionForce(): Rolling stiffness is zero" << std::endl;
170  exit(-1);
171  }
172  } //end if rolling force
173 
174  if (species->getTorsionFrictionCoefficient() != 0.0)
175  {
176  if (species->getTorsionStiffness() != 0.0)
177  {
179  Mdouble effectiveDiameter = 2.0 * getEffectiveRadius();
180 
181  //From Luding2008, spin velocity (eq 16) w/o 2.0!
182  Vec3D torsionRelativeVelocity = effectiveDiameter * Vec3D::dot(getNormal(), getP()->getAngularVelocity() -
183  getI()->getAngularVelocity()) *
184  getNormal();
185 
186  //Integrate the spring
187  torsionSpringVelocity_ = torsionRelativeVelocity;
188  //integrate(getHandler()->timeStep_);
190  Vec3D::dot(torsionSpring_ + torsionSpringVelocity_ * getHandler()->getDPMBase()->getTimeStep(),
191  getNormal()) * getNormal();
192 
193  //Calculate test force acting on P including viscous force
194  Vec3D torsionForce = -species->getTorsionStiffness() * torsionSpring_ -
195  species->getTorsionDissipation() * torsionRelativeVelocity;
196  if (getBaseSpecies()->getNormalForce()->getConstantRestitution()) torsionForce *=2.0*getEffectiveMass();
197 
198  //tangential forces are modelled by a spring-damper of elasticity kt and viscosity dispt (sticking),
199  //but the force is limited by Coulomb friction (torsion):
200  Mdouble torsionForceSquared = torsionForce.getLengthSquared();
201  if (torsionForceSquared <=
203  {
204  //if sticking (|ft|<=mu*|fn|), apply the force
205  }
206  else
207  {
208  //if torsion, resize the tangential force such that |ft|=mu*|fn|
209  torsionForce *= species->getTorsionFrictionCoefficient() * getAbsoluteNormalForce() /
210  std::sqrt(torsionForceSquared);
211  //resize the tangential spring accordingly such ft=-k*delta-nu*relVel
212  torsionSpring_ = -(torsionForce + species->getTorsionDissipation() * torsionRelativeVelocity) /
213  species->getTorsionStiffness();
214  }
215  //Add (virtual) rolling force to torque
216  addTorque(effectiveDiameter * torsionForce);
217  }
218  else //if no spring stiffness is set
219  {
220  std::cerr << "FrictionInteraction::computeFrictionForce(): Torsion stiffness is zero" << std::endl;
221  exit(-1);
222  }
223  } //end if torsion force
224 }
Mdouble getRollingFrictionCoefficient() const
Allows the (dynamic) Coulomb friction coefficient to be accessed.
const FrictionSpecies * getSpecies() const
Returns a const pointer of type FrictionSpecies*.
Mdouble getEffectiveRadius() const
Returns a Mdouble to the effective radius of the interaction. (Not corrected for the overlap) ...
InteractionHandler * getHandler() const
Gets a point to the interaction handlers to which this interaction belongs.
double Mdouble
Definition: GeneralDefine.h:34
Mdouble getTorsionFrictionCoefficient() const
Allows the (dynamic) Coulomb torsion friction coefficient to be accessed.
FrictionSpecies contains the parameters used to describe sliding, rolling and torsional friction...
void addTorque(Vec3D torque)
Mdouble getTorsionStiffness() const
Allows the torsion stiffness to be accessed.
BaseInteractable * getI()
Returns a pointer to the second object involved in the interaction (often a wall or a particle)...
static Mdouble dot(const Vec3D &a, const Vec3D &b)
Calculates the dot product of two Vec3D: .
Definition: Vector.cc:76
Mdouble getRollingDissipation() const
Allows the tangential viscosity to be accessed.
Mdouble getRollingFrictionCoefficientStatic() const
Allows the static Coulomb rolling friction coefficient to be accessed.
const Vec3D & getNormal() const
Gets the normal vector between the two interacting objects.
Mdouble getRollingStiffness() const
Allows the spring constant to be accessed.
BaseInteractable * getP()
Returns a pointer to first object involved in the interaction (normally a particle).
void computeFrictionForce()
Computes the tangential force generated due to compression in the sliding spring. Does take into acco...
const BaseSpecies * getBaseSpecies() const
Return a constant point to BaseSpecies of the interaction.
static Vec3D cross(const Vec3D &a, const Vec3D &b)
Calculates the cross product of two Vec3D: .
Definition: Vector.cc:163
Mdouble getDistance() const
Returns an Mdouble which is the norm (length) of distance vector.
Vec3D rollingSpringVelocity_
Stores the rate at which the rolling spring compresses or relaxes. Set in computeFrictionForce(), used in computing the amount of compression in rolling spring. Used in integrate().
static Mdouble getLengthSquared(const Vec3D &a)
Calculates the squared length of a Vec3D: .
Definition: Vector.h:316
virtual const Vec3D & getVelocity() const
Returns the velocity of this interactable.
Mdouble getTorsionDissipation() const
Allows the torsion viscosity to be accessed.
Definition: Vector.h:49
T square(const T val)
squares a number
Definition: ExtendedMath.h:104
DPMBase * getDPMBase()
Gets the problem that is solved using this handler.
Definition: BaseHandler.h:725
Mdouble getTimeStep() const
Returns the simulation time step.
Definition: DPMBase.cc:1211
Vec3D torsionSpring_
Stores the amount of torsional spring compression. Set in integrate(), used in computing frictional f...
Vec3D torsionSpringVelocity_
Stores the rate at which the torsional spring compresses or relaxes. Set in computeFrictionForce(), used in computing the amount of compression in torsion spring. Used in integrate().
Mdouble getTorsionFrictionCoefficientStatic() const
Allows the static Coulomb torsion friction coefficient to be accessed.
Vec3D rollingSpring_
Stores the amount of rolling spring compression. Set in integrate(), used in computing frictional for...
Mdouble getEffectiveMass() const
Returns a Mdouble to the effective radius of the interaction. (Not corrected for the overlap) ...
Mdouble getAbsoluteNormalForce() const
Returns the absolute value of the norm (length) of the Normal force vector.
std::string FrictionInteraction::getBaseName ( ) const

Returns interaction name/type.

Returns
std::string

Definition at line 264 of file FrictionInteraction.cc.

265 {
266  return "Friction";
267 }
Mdouble FrictionInteraction::getElasticEnergy ( ) const
overridevirtual

Returns the global amount of energy stored in all the springs (rolling, sliding and torsional).

Returns
Mdouble the total elastic energy stored in the frictional springs

Reimplemented from BaseInteraction.

Definition at line 239 of file FrictionInteraction.cc.

References BaseInteraction::getBaseSpecies(), BaseInteraction::getEffectiveMass(), SlidingFrictionInteraction::getElasticEnergy(), Vec3D::getLengthSquared(), FrictionSpecies::getRollingStiffness(), getSpecies(), FrictionSpecies::getTorsionStiffness(), rollingSpring_, and torsionSpring_.

240 {
241  if (getBaseSpecies()->getNormalForce()->getConstantRestitution()) {
245  } else {
249  }
250 }
const FrictionSpecies * getSpecies() const
Returns a const pointer of type FrictionSpecies*.
Mdouble getTorsionStiffness() const
Allows the torsion stiffness to be accessed.
Mdouble getElasticEnergy() const override
Returns the amount of elastic energy stored in sliding spring.
Mdouble getRollingStiffness() const
Allows the spring constant to be accessed.
const BaseSpecies * getBaseSpecies() const
Return a constant point to BaseSpecies of the interaction.
static Mdouble getLengthSquared(const Vec3D &a)
Calculates the squared length of a Vec3D: .
Definition: Vector.h:316
Vec3D torsionSpring_
Stores the amount of torsional spring compression. Set in integrate(), used in computing frictional f...
Vec3D rollingSpring_
Stores the amount of rolling spring compression. Set in integrate(), used in computing frictional for...
Mdouble getEffectiveMass() const
Returns a Mdouble to the effective radius of the interaction. (Not corrected for the overlap) ...
Vec3D FrictionInteraction::getRollingSpring ( ) const

Definition at line 293 of file FrictionInteraction.cc.

References rollingSpring_.

294 {
295  return rollingSpring_;
296 }
Vec3D rollingSpring_
Stores the amount of rolling spring compression. Set in integrate(), used in computing frictional for...
const FrictionSpecies * FrictionInteraction::getSpecies ( ) const

Returns a const pointer of type FrictionSpecies*.

Returns
const FrictionSpecies*

Definition at line 255 of file FrictionInteraction.cc.

References BaseInteraction::getBaseSpecies(), and BaseSpecies::getFrictionForce().

Referenced by computeFrictionForce(), and getElasticEnergy().

256 {
257  return static_cast<const FrictionSpecies*>(getBaseSpecies()->getFrictionForce());
258 ;
259 }
FrictionSpecies contains the parameters used to describe sliding, rolling and torsional friction...
BaseFrictionForce * getFrictionForce() const
Definition: BaseSpecies.h:150
const BaseSpecies * getBaseSpecies() const
Return a constant point to BaseSpecies of the interaction.
Vec3D FrictionInteraction::getTorsionSpring ( ) const

Definition at line 298 of file FrictionInteraction.cc.

References torsionSpring_.

299 {
300  return torsionSpring_;
301 }
Vec3D torsionSpring_
Stores the amount of torsional spring compression. Set in integrate(), used in computing frictional f...
void FrictionInteraction::integrate ( Mdouble timeStep  )
overridevirtual

Computes the amount of compression in all the springs, i.e., increments the rollingSpring_, slidingSpring_ (see SlidingFrictionInteraction.cc) and torsionSpring_.

Parameters
[in]timeStepthe amount of time by which the solution is evolved

Reimplemented from BaseInteraction.

Definition at line 229 of file FrictionInteraction.cc.

References Vec3D::dot(), BaseInteraction::getNormal(), SlidingFrictionInteraction::integrate(), rollingSpring_, rollingSpringVelocity_, torsionSpring_, and torsionSpringVelocity_.

230 {
234 }
static Mdouble dot(const Vec3D &a, const Vec3D &b)
Calculates the dot product of two Vec3D: .
Definition: Vector.cc:76
const Vec3D & getNormal() const
Gets the normal vector between the two interacting objects.
Vec3D rollingSpringVelocity_
Stores the rate at which the rolling spring compresses or relaxes. Set in computeFrictionForce(), used in computing the amount of compression in rolling spring. Used in integrate().
void integrate(Mdouble timeStep) override
Increments the amount of compression in sliding spring.
Vec3D torsionSpring_
Stores the amount of torsional spring compression. Set in integrate(), used in computing frictional f...
Vec3D torsionSpringVelocity_
Stores the rate at which the torsional spring compresses or relaxes. Set in computeFrictionForce(), used in computing the amount of compression in torsion spring. Used in integrate().
Vec3D rollingSpring_
Stores the amount of rolling spring compression. Set in integrate(), used in computing frictional for...
void FrictionInteraction::read ( std::istream &  is)
overridevirtual

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

Parameters
in/out]is input file stream

Reimplemented from BaseInteraction.

Definition at line 97 of file FrictionInteraction.cc.

References SlidingFrictionInteraction::read(), rollingSpring_, and torsionSpring_.

98 {
100  std::string dummy;
101  is >> dummy >> rollingSpring_;
102  is >> dummy >> torsionSpring_;
103 }
void read(std::istream &is) override
Interaction read function, which accepts an std::istream as input.
Vec3D torsionSpring_
Stores the amount of torsional spring compression. Set in integrate(), used in computing frictional f...
Vec3D rollingSpring_
Stores the amount of rolling spring compression. Set in integrate(), used in computing frictional for...
void FrictionInteraction::reverseHistory ( )
overridevirtual

A useful feature if one wants to return to the initial state of the springs. However, reverse history decrements the current state to the state corresponding to previous time step. Decrements the state or value of rollingSpring_, torsionSpring_ and slidingSpring_.

Reimplemented from BaseInteraction.

Definition at line 272 of file FrictionInteraction.cc.

References SlidingFrictionInteraction::reverseHistory(), torsionSpring_, and torsionSpringVelocity_.

273 {
275  //rollingSpring_=-rollingSpring_;
276  //rollingSpringVelocity_=-rollingSpringVelocity_;
279 }
void reverseHistory() override
A useful feature if one wants to return to the initial state of the spring. However, reverse history decrements the current state to the state corresponding to previous time step. Decrements the value of slidingSpring_.
Vec3D torsionSpring_
Stores the amount of torsional spring compression. Set in integrate(), used in computing frictional f...
Vec3D torsionSpringVelocity_
Stores the rate at which the torsional spring compresses or relaxes. Set in computeFrictionForce(), used in computing the amount of compression in torsion spring. Used in integrate().
void FrictionInteraction::rotateHistory ( Matrix3D rotationMatrix)
overridevirtual

When periodic particles are used, some interactions need certain history properties rotated (e.g. tangential springs). This is the function for that.

Todo:
some of these might be unneccesary

Reimplemented from BaseInteraction.

Definition at line 284 of file FrictionInteraction.cc.

References rollingSpring_, rollingSpringVelocity_, SlidingFrictionInteraction::rotateHistory(), torsionSpring_, and torsionSpringVelocity_.

285 {
287  rollingSpring_ = rotationMatrix * rollingSpring_;
289  torsionSpring_ = rotationMatrix * torsionSpring_;
291 }
void rotateHistory(Matrix3D &rotationMatrix) override
When periodic particles are used, some interactions need certain history properties rotated (e...
Vec3D rollingSpringVelocity_
Stores the rate at which the rolling spring compresses or relaxes. Set in computeFrictionForce(), used in computing the amount of compression in rolling spring. Used in integrate().
Vec3D torsionSpring_
Stores the amount of torsional spring compression. Set in integrate(), used in computing frictional f...
Vec3D torsionSpringVelocity_
Stores the rate at which the torsional spring compresses or relaxes. Set in computeFrictionForce(), used in computing the amount of compression in torsion spring. Used in integrate().
Vec3D rollingSpring_
Stores the amount of rolling spring compression. Set in integrate(), used in computing frictional for...
void FrictionInteraction::setRollingSpring ( Vec3D  rollingSpring)

Definition at line 303 of file FrictionInteraction.cc.

References rollingSpring_.

304 {
305  rollingSpring_ = rollingSpring;
306 }
Vec3D rollingSpring_
Stores the amount of rolling spring compression. Set in integrate(), used in computing frictional for...
void FrictionInteraction::setTorsionSpring ( Vec3D  torsionSpring)

Definition at line 308 of file FrictionInteraction.cc.

References torsionSpring_.

309 {
310  torsionSpring_ = torsionSpring;
311 }
Vec3D torsionSpring_
Stores the amount of torsional spring compression. Set in integrate(), used in computing frictional f...
void FrictionInteraction::write ( std::ostream &  os) const
overridevirtual

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

Parameters
in/out]os output file stream

Reimplemented from BaseInteraction.

Definition at line 87 of file FrictionInteraction.cc.

References rollingSpring_, torsionSpring_, and SlidingFrictionInteraction::write().

88 {
90  os << " rollingSpring " << rollingSpring_;
91  os << " torsionSpring " << torsionSpring_;
92 }
Vec3D torsionSpring_
Stores the amount of torsional spring compression. Set in integrate(), used in computing frictional f...
Vec3D rollingSpring_
Stores the amount of rolling spring compression. Set in integrate(), used in computing frictional for...
void write(std::ostream &os) const override
Interaction write function, which accepts an std::ostream as input.

Member Data Documentation

Vec3D FrictionInteraction::rollingSpring_
private

Stores the amount of rolling spring compression. Set in integrate(), used in computing frictional force due to rolling.

Definition at line 129 of file FrictionInteraction.h.

Referenced by computeFrictionForce(), FrictionInteraction(), getElasticEnergy(), getRollingSpring(), integrate(), read(), rotateHistory(), setRollingSpring(), and write().

Vec3D FrictionInteraction::rollingSpringVelocity_
private

Stores the rate at which the rolling spring compresses or relaxes. Set in computeFrictionForce(), used in computing the amount of compression in rolling spring. Used in integrate().

Definition at line 134 of file FrictionInteraction.h.

Referenced by computeFrictionForce(), integrate(), and rotateHistory().

Vec3D FrictionInteraction::torsionSpring_
private

Stores the amount of torsional spring compression. Set in integrate(), used in computing frictional force due to torsion.

Definition at line 139 of file FrictionInteraction.h.

Referenced by computeFrictionForce(), FrictionInteraction(), getElasticEnergy(), getTorsionSpring(), integrate(), read(), reverseHistory(), rotateHistory(), setTorsionSpring(), and write().

Vec3D FrictionInteraction::torsionSpringVelocity_
private

Stores the rate at which the torsional spring compresses or relaxes. Set in computeFrictionForce(), used in computing the amount of compression in torsion spring. Used in integrate().

Definition at line 144 of file FrictionInteraction.h.

Referenced by computeFrictionForce(), integrate(), reverseHistory(), and rotateHistory().


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