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SlidingFrictionInteraction Class Reference

Computes the forces corresponding to sliding friction. More...

#include <SlidingFrictionInteraction.h>

+ Inheritance diagram for SlidingFrictionInteraction:

Public Types

typedef SlidingFrictionSpecies SpeciesType
 An alias name for SlidingFrictionSpecies data type. More...
 

Public Member Functions

 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
 

Protected Attributes

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_
 

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...
 

Detailed Description

Computes the forces corresponding to sliding friction.

Definition at line 42 of file SlidingFrictionInteraction.h.

Member Typedef Documentation

Constructor & Destructor Documentation

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

Constructor.

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

Definition at line 40 of file SlidingFrictionInteraction.cc.

References isSuperQuadricInteraction_, Vec3D::setZero(), and slidingSpring_.

41  : BaseInteraction(P, I, timeStamp)
42 {
45 #ifdef DEBUG_CONSTRUCTOR
46  std::cout<<"SlidingFrictionInteraction::SlidingFrictionInteraction() finished"<<std::endl;
47 #endif
48 }
void setZero()
Sets all elements to zero.
Definition: Vector.cc:43
Vec3D slidingSpring_
Stores the amount of sliding spring ( ) compression from the expression . Set in the member function ...
SlidingFrictionInteraction::SlidingFrictionInteraction ( )

Definition at line 51 of file SlidingFrictionInteraction.cc.

References isSuperQuadricInteraction_, Vec3D::setZero(), and slidingSpring_.

52  : BaseInteraction()
53 {
56 #ifdef DEBUG_CONSTRUCTOR
57  std::cout<<"SlidingFrictionInteraction::SlidingFrictionInteraction() finished"<<std::endl;
58 #endif
59 }
void setZero()
Sets all elements to zero.
Definition: Vector.cc:43
Vec3D slidingSpring_
Stores the amount of sliding spring ( ) compression from the expression . Set in the member function ...
SlidingFrictionInteraction::SlidingFrictionInteraction ( const SlidingFrictionInteraction p)

Copy constructor.

Parameters
[in]p

Definition at line 64 of file SlidingFrictionInteraction.cc.

References isSuperQuadricInteraction_, and slidingSpring_.

65  : BaseInteraction(p)
66 {
69 #ifdef DEBUG_CONSTRUCTOR
70  std::cout<<"SlidingFrictionInteraction::SlidingFrictionInteraction(const SlidingFrictionInteraction& p) finished"<<std::endl;
71 #endif
72 }
Vec3D slidingSpring_
Stores the amount of sliding spring ( ) compression from the expression . Set in the member function ...
SlidingFrictionInteraction::~SlidingFrictionInteraction ( )
override

Destructor.

Definition at line 77 of file SlidingFrictionInteraction.cc.

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

Member Function Documentation

void SlidingFrictionInteraction::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.

Definition at line 106 of file SlidingFrictionInteraction.cc.

References BaseInteraction::addForce(), computeSlidingSpring(), computeSlidingSpringSuperQuadric(), BaseInteraction::getAbsoluteNormalForce(), BaseInteraction::getBaseSpecies(), BaseInteraction::getEffectiveMass(), SlidingFrictionSpecies::getIsSuperquadricSpecies(), Vec3D::getLengthSquared(), BaseInteraction::getNormal(), BaseInteraction::getNormalRelativeVelocity(), BaseInteraction::getRelativeVelocity(), SlidingFrictionSpecies::getSlidingDissipation(), SlidingFrictionSpecies::getSlidingFrictionCoefficient(), SlidingFrictionSpecies::getSlidingFrictionCoefficientStatic(), SlidingFrictionSpecies::getSlidingStiffness(), getSpecies(), isSuperQuadricInteraction_, slidingSpring_, mathsFunc::square(), and tangentialForce_.

Referenced by FrictionInteraction::computeFrictionForce().

107 {
108  //If tangential forces are absent
109  if (getAbsoluteNormalForce() == 0.0) return;
110 
111  const SlidingFrictionSpecies* species = getSpecies();//dynamic_cast
113 
114  if (species->getSlidingFrictionCoefficient() != 0.0)
115  {
116  //Compute the tangential component of relativeVelocity_
117  // relativeVelocity = [v_p + (r_p-c) x w_p] - [v_i + (r_i-c) x w_i]
118  // tangentialRelativeVelocity = relativeVelocity - (relativeVelocity . n) n
119  Vec3D tangentialRelativeVelocity = getRelativeVelocity() - getNormal() * getNormalRelativeVelocity();
120 
121  if (species->getSlidingStiffness() != 0.0)
122  {
124  {
125  computeSlidingSpring(tangentialRelativeVelocity);
126  }
127  else
128  {
129  computeSlidingSpringSuperQuadric(tangentialRelativeVelocity);
130  }
131 
132  //Calculate test force acting on P including viscous force
134  species->getSlidingDissipation() * tangentialRelativeVelocity;
135  if (getBaseSpecies()->getNormalForce()->getConstantRestitution()) tangentialForce_ *=2.0*getEffectiveMass();
136 
137  //tangential forces are modelled by a spring-damper of elasticity kt and viscosity dispt (sticking),
138  //but the force is limited by Coulomb friction (sliding):
139  Mdouble tangentialForceSquared = tangentialForce_.getLengthSquared();
140  if (tangentialForceSquared <=
142  {
143  //if sticking (|ft|<=mu*|fn|), apply the force
145  }
146  else
147  {
148  //if sliding, resize the tangential force such that |ft|=mu*|fn|
150  std::sqrt(tangentialForceSquared);
152  //resize the tangential spring accordingly such ft=-k*delta-nu*relVel
153  slidingSpring_ = -(tangentialForce_ + species->getSlidingDissipation() * tangentialRelativeVelocity) /
154  species->getSlidingStiffness();
155  }
156  }
157  else //if no spring stiffness is set
158  {
159 // if (species->getSlidingDissipation()==0.0)
160 // {
161 // std::cerr << "SlidingFrictionInteraction::getForce(): warning: both sliding stiffness and dissipation are zero" << std::endl;
162 // }
163  Mdouble tangentialRelativeVelocitySquared = tangentialRelativeVelocity.getLengthSquared();
164  if (tangentialRelativeVelocitySquared * mathsFunc::square(species->getSlidingDissipation()) <=
166  tangentialForce_ = -species->getSlidingDissipation() * tangentialRelativeVelocity;
167  else //if sliding, set force to Coulomb limit
169  std::sqrt(tangentialRelativeVelocitySquared)) * tangentialRelativeVelocity;
170 
172  }
173  }
174 
175  /* And if species->getSlidingFrictionCoefficient() == 0.0, then there is no
176  * friction force at all. */
177 }
Mdouble getSlidingFrictionCoefficientStatic() const
Allows the static Coulomb friction coefficient to be accessed.
double Mdouble
Definition: GeneralDefine.h:34
const Vec3D & getRelativeVelocity() const
Returns a constant reference to a vector of relative velocity.
const Vec3D & getNormal() const
Gets the normal vector between the two interacting objects.
Vec3D tangentialForce_
Computes the tangential force such that . Set and computed in computeFrictionForce().
void computeSlidingSpringSuperQuadric(const Vec3D &tangentialRelativeVelocity)
Mdouble getNormalRelativeVelocity() const
Returns a double which is the norm (length) of the relative velocity vector.
const BaseSpecies * getBaseSpecies() const
Return a constant point to BaseSpecies of the interaction.
const SlidingFrictionSpecies * getSpecies() const
Returns a const pointer of type SlidingFrictionSpecies*.
Vec3D slidingSpring_
Stores the amount of sliding spring ( ) compression from the expression . Set in the member function ...
void addForce(Vec3D force)
add an force increment to the total force.
SlidingFrictionSpecies contains the parameters used to describe sliding friction. ...
Mdouble getSlidingStiffness() const
Allows the spring constant to be accessed.
static Mdouble getLengthSquared(const Vec3D &a)
Calculates the squared length of a Vec3D: .
Definition: Vector.h:316
Mdouble getSlidingDissipation() const
Allows the tangential viscosity to be accessed.
Definition: Vector.h:49
T square(const T val)
squares a number
Definition: ExtendedMath.h:104
void computeSlidingSpring(const Vec3D &tangentialRelativeVelocity)
Mdouble getEffectiveMass() const
Returns a Mdouble to the effective radius of the interaction. (Not corrected for the overlap) ...
Mdouble getSlidingFrictionCoefficient() const
Allows the (dynamic) Coulomb friction coefficient to be accessed.
Mdouble getAbsoluteNormalForce() const
Returns the absolute value of the norm (length) of the Normal force vector.
void SlidingFrictionInteraction::computeSlidingSpring ( const Vec3D tangentialRelativeVelocity)

Definition at line 179 of file SlidingFrictionInteraction.cc.

References Vec3D::dot(), BaseInteraction::getDistance(), BaseHandler< T >::getDPMBase(), BaseInteraction::getHandler(), BaseInteraction::getI(), BaseInteraction::getNormal(), BaseInteraction::getP(), DPMBase::getTimeStep(), slidingSpring_, and slidingSpringVelocity_.

Referenced by computeFrictionForce().

180 {
181  //used to Integrate the spring
182  if (dynamic_cast<BaseParticle*>(getI()) == nullptr) //if particle-wall
183  {
184  slidingSpringVelocity_ = tangentialRelativeVelocity;
185  }
186  else //if particle-particle
187  {
188  slidingSpringVelocity_ = (tangentialRelativeVelocity -
189  Vec3D::dot(slidingSpring_, getP()->getVelocity() - getI()->getVelocity()) *
190  getNormal() / getDistance());
191  }
192  // v_s = v_t - [xi . (v_p-v_i)/|r_pi|] n
193 
194 
195  //integrate(getHandler()->timeStep_);
196  // xi = xi' + dt v_s
198  // Stefan does [EJECE-12/2008] sth. like xi = xi' - (xi . n) n + dt*v_t, see SlidingFrictionSuperQuadricInteraction
199 }
Vec3D slidingSpringVelocity_
Stores the rate at which the sliding spring compressed or relaxed. Set in the member function compute...
InteractionHandler * getHandler() const
Gets a point to the interaction handlers to which this interaction belongs.
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
const Vec3D & getNormal() const
Gets the normal vector between the two interacting objects.
BaseInteractable * getP()
Returns a pointer to first object involved in the interaction (normally a particle).
Vec3D slidingSpring_
Stores the amount of sliding spring ( ) compression from the expression . Set in the member function ...
Mdouble getDistance() const
Returns an Mdouble which is the norm (length) of distance vector.
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
void SlidingFrictionInteraction::computeSlidingSpringSuperQuadric ( const Vec3D tangentialRelativeVelocity)

Definition at line 201 of file SlidingFrictionInteraction.cc.

References DEBUG, Vec3D::dot(), BaseHandler< T >::getDPMBase(), BaseInteraction::getHandler(), BaseInteraction::getI(), Vec3D::getLength(), BaseInteraction::getNormal(), DPMBase::getTimeStep(), logger, Vec3D::normalise(), slidingSpring_, and slidingSpringVelocity_.

Referenced by computeFrictionForce().

202 {
203  //used to Integrate the spring
204  if (dynamic_cast<BaseParticle*>(getI()) == nullptr) //if particle-wall
205  {
206  slidingSpringVelocity_ = tangentialRelativeVelocity;
207  }
208  else //if particle-particle
209  {
210  slidingSpringVelocity_ = tangentialRelativeVelocity;
211  }
212 
213  // From Stefan [EJECE-12/2008]:
214  // xi = xi' - (xi . n) n and renormalising, then add v_t * dt
215  logger(DEBUG, "sliding spring, normal before rotation-step: %, %", slidingSpring_, getNormal());
216  if (slidingSpring_.getLength() > 1e-10)
217  {
218  const Mdouble springLength = slidingSpring_.getLength();
221  slidingSpring_ *= springLength;
222  logger.assert(std::abs(slidingSpring_.getLength() - springLength) < 1e-10, "Spring length not the same after rotation");
223  }
224  logger(DEBUG, "sliding spring after rotation-step: %\n", slidingSpring_);
226  logger.assert(std::abs(Vec3D::dot(slidingSpring_, getNormal())) < 1e-10, "sliding spring not perpendicular to normal");
227 }
Vec3D slidingSpringVelocity_
Stores the rate at which the sliding spring compressed or relaxed. Set in the member function compute...
Logger< MERCURY_LOGLEVEL > logger("MercuryKernel")
InteractionHandler * getHandler() const
Gets a point to the interaction handlers to which this interaction belongs.
double Mdouble
Definition: GeneralDefine.h:34
void normalise()
Makes this Vec3D unit length.
Definition: Vector.cc:123
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
static Mdouble getLength(const Vec3D &a)
Calculates the length of a Vec3D: .
Definition: Vector.cc:331
const Vec3D & getNormal() const
Gets the normal vector between the two interacting objects.
Vec3D slidingSpring_
Stores the amount of sliding spring ( ) compression from the expression . Set in the member function ...
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
std::string SlidingFrictionInteraction::getBaseName ( ) const

Returns the type/name of interaction (sliding friction interaction)

Returns
std::string

Definition at line 279 of file SlidingFrictionInteraction.cc.

280 {
281  return "SlidingFriction";
282 }
Mdouble SlidingFrictionInteraction::getElasticEnergy ( ) const
overridevirtual

Returns the amount of elastic energy stored in sliding spring.

Returns
Mdouble

Reimplemented from BaseInteraction.

Definition at line 241 of file SlidingFrictionInteraction.cc.

References BaseInteraction::getBaseSpecies(), BaseInteraction::getEffectiveMass(), Vec3D::getLengthSquared(), SlidingFrictionSpecies::getSlidingStiffness(), getSpecies(), and slidingSpring_.

Referenced by FrictionInteraction::getElasticEnergy().

242 {
243  if (getBaseSpecies()->getNormalForce()->getConstantRestitution()) {
245  } else {
247  }
248 }
const BaseSpecies * getBaseSpecies() const
Return a constant point to BaseSpecies of the interaction.
const SlidingFrictionSpecies * getSpecies() const
Returns a const pointer of type SlidingFrictionSpecies*.
Vec3D slidingSpring_
Stores the amount of sliding spring ( ) compression from the expression . Set in the member function ...
Mdouble getSlidingStiffness() const
Allows the spring constant to be accessed.
static Mdouble getLengthSquared(const Vec3D &a)
Calculates the squared length of a Vec3D: .
Definition: Vector.h:316
Mdouble getEffectiveMass() const
Returns a Mdouble to the effective radius of the interaction. (Not corrected for the overlap) ...
Vec3D SlidingFrictionInteraction::getSlidingSpring ( ) const

Definition at line 307 of file SlidingFrictionInteraction.cc.

References slidingSpring_.

308 {
309  return slidingSpring_;
310 }
Vec3D slidingSpring_
Stores the amount of sliding spring ( ) compression from the expression . Set in the member function ...
const SlidingFrictionSpecies * SlidingFrictionInteraction::getSpecies ( ) const

Returns a const pointer of type SlidingFrictionSpecies*.

Returns
const SlidingFrictionSpecies*

Definition at line 270 of file SlidingFrictionInteraction.cc.

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

Referenced by computeFrictionForce(), and getElasticEnergy().

271 {
272  return static_cast<const SlidingFrictionSpecies*>(getBaseSpecies()->getFrictionForce());
273 ;
274 }
BaseFrictionForce * getFrictionForce() const
Definition: BaseSpecies.h:150
const BaseSpecies * getBaseSpecies() const
Return a constant point to BaseSpecies of the interaction.
SlidingFrictionSpecies contains the parameters used to describe sliding friction. ...
const Vec3D SlidingFrictionInteraction::getTangentialForce ( ) const
overridevirtual

Returns the sliding friction force vector.

Returns
const Vec3D

Reimplemented from BaseInteraction.

Definition at line 262 of file SlidingFrictionInteraction.cc.

References tangentialForce_.

263 {
264  return tangentialForce_;
265 }
Vec3D tangentialForce_
Computes the tangential force such that . Set and computed in computeFrictionForce().
Mdouble SlidingFrictionInteraction::getTangentialOverlap ( ) const
overridevirtual

Returns the amount of tangential overlap which is needed by BaseInteraction::writeToFstat().

Returns
Mdouble
Todo:
TWnow this should be positive

Reimplemented from BaseInteraction.

Definition at line 253 of file SlidingFrictionInteraction.cc.

References Vec3D::getLength(), and slidingSpring_.

254 {
256  return -slidingSpring_.getLength();
257 }
static Mdouble getLength(const Vec3D &a)
Calculates the length of a Vec3D: .
Definition: Vector.cc:331
Vec3D slidingSpring_
Stores the amount of sliding spring ( ) compression from the expression . Set in the member function ...
void SlidingFrictionInteraction::integrate ( Mdouble timeStep  )
overridevirtual

Increments the amount of compression in sliding spring.

Parameters
[in]timeStepthe dt

Reimplemented from BaseInteraction.

Definition at line 233 of file SlidingFrictionInteraction.cc.

References slidingSpring_, and slidingSpringVelocity_.

Referenced by FrictionInteraction::integrate().

234 {
236 }
Vec3D slidingSpringVelocity_
Stores the rate at which the sliding spring compressed or relaxed. Set in the member function compute...
Vec3D slidingSpring_
Stores the amount of sliding spring ( ) compression from the expression . Set in the member function ...
void SlidingFrictionInteraction::moveSlidingSpring ( Vec3D  displacement)

Definition at line 312 of file SlidingFrictionInteraction.cc.

References slidingSpring_.

313 {
314  slidingSpring_ += displacement;
315 }
Vec3D slidingSpring_
Stores the amount of sliding spring ( ) compression from the expression . Set in the member function ...
void SlidingFrictionInteraction::read ( std::istream &  is)
overridevirtual

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

Parameters
[in,out]is

Reimplemented from BaseInteraction.

Definition at line 96 of file SlidingFrictionInteraction.cc.

References slidingSpring_.

Referenced by FrictionInteraction::read().

97 {
98  //BaseInteraction::read(is);
99  std::string dummy;
100  is >> dummy >> slidingSpring_;
101 }
Vec3D slidingSpring_
Stores the amount of sliding spring ( ) compression from the expression . Set in the member function ...
void SlidingFrictionInteraction::reverseHistory ( )
overridevirtual

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_.

Reimplemented from BaseInteraction.

Definition at line 293 of file SlidingFrictionInteraction.cc.

References slidingSpring_, slidingSpringVelocity_, and tangentialForce_.

Referenced by FrictionInteraction::reverseHistory().

294 {
298 }
Vec3D slidingSpringVelocity_
Stores the rate at which the sliding spring compressed or relaxed. Set in the member function compute...
Vec3D tangentialForce_
Computes the tangential force such that . Set and computed in computeFrictionForce().
Vec3D slidingSpring_
Stores the amount of sliding spring ( ) compression from the expression . Set in the member function ...
void SlidingFrictionInteraction::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 300 of file SlidingFrictionInteraction.cc.

References slidingSpring_, slidingSpringVelocity_, and tangentialForce_.

Referenced by FrictionInteraction::rotateHistory().

301 {
302  slidingSpring_ = rotationMatrix * slidingSpring_;
304  tangentialForce_ = rotationMatrix * tangentialForce_;
305 }
Vec3D slidingSpringVelocity_
Stores the rate at which the sliding spring compressed or relaxed. Set in the member function compute...
Vec3D tangentialForce_
Computes the tangential force such that . Set and computed in computeFrictionForce().
Vec3D slidingSpring_
Stores the amount of sliding spring ( ) compression from the expression . Set in the member function ...
void SlidingFrictionInteraction::setIsSuperQuadricInteraction ( bool  isSuperQuadricInteraction)

Definition at line 317 of file SlidingFrictionInteraction.cc.

References isSuperQuadricInteraction_.

318 {
319  isSuperQuadricInteraction_ = isSuperQuadricInteraction;
320 }
void SlidingFrictionInteraction::setSlidingSpring ( Vec3D  slidingSpring)
Bug:
may need to remove the consts

Definition at line 285 of file SlidingFrictionInteraction.cc.

References slidingSpring_.

286 {
287  slidingSpring_ = slidingSpring;
288 }
Vec3D slidingSpring_
Stores the amount of sliding spring ( ) compression from the expression . Set in the member function ...
void SlidingFrictionInteraction::write ( std::ostream &  os) const
overridevirtual

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

Parameters
[in,out]os

Reimplemented from BaseInteraction.

Definition at line 87 of file SlidingFrictionInteraction.cc.

References slidingSpring_.

Referenced by FrictionInteraction::write().

88 {
89  //BaseInteraction::write(os);
90  os << " slidingSpring " << slidingSpring_;
91 }
Vec3D slidingSpring_
Stores the amount of sliding spring ( ) compression from the expression . Set in the member function ...

Member Data Documentation

bool SlidingFrictionInteraction::isSuperQuadricInteraction_
protected
Vec3D SlidingFrictionInteraction::slidingSpring_
protected

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().

Definition at line 142 of file SlidingFrictionInteraction.h.

Referenced by computeFrictionForce(), computeSlidingSpring(), computeSlidingSpringSuperQuadric(), getElasticEnergy(), getSlidingSpring(), getTangentialOverlap(), integrate(), moveSlidingSpring(), read(), reverseHistory(), rotateHistory(), setSlidingSpring(), SlidingFrictionInteraction(), and write().

Vec3D SlidingFrictionInteraction::slidingSpringVelocity_
protected

Stores the rate at which the sliding spring compressed or relaxed. Set in the member function computeFrictionForce() and used in integrate().

Definition at line 147 of file SlidingFrictionInteraction.h.

Referenced by computeSlidingSpring(), computeSlidingSpringSuperQuadric(), integrate(), reverseHistory(), and rotateHistory().

Vec3D SlidingFrictionInteraction::tangentialForce_
protected

Computes the tangential force such that \(|f_t|=\mu*|f_n|\). Set and computed in computeFrictionForce().

Definition at line 151 of file SlidingFrictionInteraction.h.

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


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