Description

Class which defines a mesh of finite elements of class ChElementBase, between nodes of class ChNodeFEAbase.

#include <ChMesh.h>

Inheritance diagram for chrono::fea::ChMesh:

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Collaboration diagram for chrono::fea::ChMesh:

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Public Member Functions
	ChMesh (const ChMesh &other)

virtual ChMesh *	Clone () const override
	"Virtual" copy constructor (covariant return type).

void	AddNode (std::shared_ptr< ChNodeFEAbase > m_node)

void	AddElement (std::shared_ptr< ChElementBase > m_elem)

void	ClearNodes ()

void	ClearElements ()

const std::vector< std::shared_ptr< ChNodeFEAbase > > &	GetNodes () const
	Get the array of nodes of this mesh.

const std::vector< std::shared_ptr< ChElementBase > > &	GetElements () const
	Get the array of elements of this mesh.

virtual std::shared_ptr< ChNodeBase >	GetNode (unsigned int n) override
	Access the N-th node.

std::shared_ptr< ChElementBase >	GetElement (unsigned int n)
	Access the N-th element.

virtual unsigned int	GetNnodes () const override
	Get the number of nodes in the mesh.

unsigned int	GetNelements ()
	Get the number of elements in the mesh.

virtual int	GetDOF () override
	Get the number of scalar coordinates (variables), if any, in this item. More...

virtual int	GetDOF_w () override
	Get the number of scalar coordinates of variables derivatives (usually = DOF, but might be different than DOF, ex. More...

virtual bool	GetCollide () const override
	Override default in ChPhysicsItem.

void	ResetCounters ()
	Reset counters for internal force and Jacobian evaluations.

int	GetNumCallsInternalForces ()
	Get cumulative number of calls to internal forces evaluation.

int	GetNumCallsJacobianLoad ()
	Get cumulative number of calls to load Jacobian information.

void	ResetTimers ()
	Reset timers for internal force and Jacobian evaluations.

double	GetTimeInternalForces ()
	Get cumulative time for internal force evaluation.

double	GetTimeJacobianLoad ()
	Get cumulative time for Jacobian load calls.

void	AddContactSurface (std::shared_ptr< ChContactSurface > m_surf)
	Add a contact surface.

std::shared_ptr< ChContactSurface >	GetContactSurface (unsigned int n)
	Access the N-th contact surface.

unsigned int	GetNcontactSurfaces ()
	Get number of added contact surfaces.

void	ClearContactSurfaces ()
	Remove all contact surfaces.

void	AddMeshSurface (std::shared_ptr< ChMeshSurface > m_surf)
	Add a mesh surface (set of ChLoadableUV items that support area loads such as pressure).

std::shared_ptr< ChMeshSurface >	GetMeshSurface (unsigned int n)
	Access the N-th mesh surface.

unsigned int	GetNmeshSurfaces ()
	Get number of added mesh surfaces.

void	ClearMeshSurfaces ()
	Remove all mesh surfaces.

void	Relax ()
	Set reference position of nodes as current position, for all nodes.

void	SetNoSpeedNoAcceleration () override
	Set no speed and no accelerations in nodes (but does not change reference positions).

virtual void	Setup () override
	This recomputes the number of DOFs, constraints, as well as state offsets of contained items.

virtual void	Update (double m_time, bool update_assets=true) override
	Update time dependent data, for all elements. More...

virtual void	SyncCollisionModels () override
	If this physical item contains one or more collision models, synchronize their coordinates and bounding boxes to the state of the item.

virtual void	AddCollisionModelsToSystem () override
	If this physical item contains one or more collision models, add them to the system's collision engine.

virtual void	RemoveCollisionModelsFromSystem () override
	If this physical item contains one or more collision models, remove them from the system's collision engine.

void	SetAutomaticGravity (bool mg, int num_points=1)
	If true, as by default, this mesh will add automatically a gravity load to all contained elements (that support gravity) using the G value from the ChSystem. More...

bool	GetAutomaticGravity ()
	Tell if this mesh will add automatically a gravity load to all contained elements.

void	ComputeMassProperties (double &mass, ChVector<> &com, ChMatrix33<> &inertia)
	Get ChMesh mass properties. More...

virtual void	IntStateGather (const unsigned int off_x, ChState &x, const unsigned int off_v, ChStateDelta &v, double &T) override
	From item's state to global state vectors y={x,v} pasting the states at the specified offsets. More...

virtual void	IntStateScatter (const unsigned int off_x, const ChState &x, const unsigned int off_v, const ChStateDelta &v, const double T) override
	From global state vectors y={x,v} to item's state (and update) fetching the states at the specified offsets. More...

virtual void	IntStateGatherAcceleration (const unsigned int off_a, ChStateDelta &a) override
	From item's state acceleration to global acceleration vector. More...

virtual void	IntStateScatterAcceleration (const unsigned int off_a, const ChStateDelta &a) override
	From global acceleration vector to item's state acceleration. More...

virtual void	IntStateIncrement (const unsigned int off_x, ChState &x_new, const ChState &x, const unsigned int off_v, const ChStateDelta &Dv) override
	Computes x_new = x + Dt , using vectors at specified offsets. More...

virtual void	IntLoadResidual_F (const unsigned int off, ChVectorDynamic<> &R, const double c) override
	Takes the F force term, scale and adds to R at given offset: R += c*F. More...

virtual void	IntLoadResidual_Mv (const unsigned int off, ChVectorDynamic<> &R, const ChVectorDynamic<> &w, const double c) override
	Takes the Mv term, multiplying mass by a vector, scale and adds to R at given offset: R += cM*w. More...

virtual void	IntToDescriptor (const unsigned int off_v, const ChStateDelta &v, const ChVectorDynamic<> &R, const unsigned int off_L, const ChVectorDynamic<> &L, const ChVectorDynamic<> &Qc) override
	Prepare variables and constraints to accommodate a solution: More...

virtual void	IntFromDescriptor (const unsigned int off_v, ChStateDelta &v, const unsigned int off_L, ChVectorDynamic<> &L) override
	After a solver solution, fetch values from variables and constraints into vectors: More...

virtual void	InjectKRMmatrices (ChSystemDescriptor &mdescriptor) override
	Tell to a system descriptor that there are items of type ChKblock in this object (for further passing it to a solver) Basically does nothing, but maybe that inherited classes may specialize this.

virtual void	KRMmatricesLoad (double Kfactor, double Rfactor, double Mfactor) override
	Adds the current stiffness K and damping R and mass M matrices in encapsulated ChKblock item(s), if any. More...

virtual void	VariablesFbReset () override
	Sets the 'fb' part (the known term) of the encapsulated ChVariables to zero.

virtual void	VariablesFbLoadForces (double factor=1) override
	Adds the current forces (applied to item) into the encapsulated ChVariables, in the 'fb' part: qf+=forces*factor.

virtual void	VariablesQbLoadSpeed () override
	Initialize the 'qb' part of the ChVariables with the current value of speeds. More...

virtual void	VariablesFbIncrementMq () override
	Adds M*q (masses multiplied current 'qb') to Fb, ex. More...

virtual void	VariablesQbSetSpeed (double step=0) override
	Fetches the item speed (ex. More...

virtual void	VariablesQbIncrementPosition (double step) override
	Increment item positions by the 'qb' part of the ChVariables, multiplied by a 'step' factor. More...

virtual void	InjectVariables (ChSystemDescriptor &mdescriptor) override
	Tell to a system descriptor that there are variables of type ChVariables in this object (for further passing it to a solver) Basically does nothing, but maybe that inherited classes may specialize this.

Public Member Functions inherited from chrono::ChIndexedNodes
	ChIndexedNodes (const ChIndexedNodes &other)

virtual void	ArchiveOUT (ChArchiveOut &marchive) override
	Add a new node to the particle cluster, passing a vector as initial position. More...

virtual void	ArchiveIN (ChArchiveIn &marchive) override
	Method to allow deserialization of transient data from archives.

Public Member Functions inherited from chrono::ChPhysicsItem
	ChPhysicsItem (const ChPhysicsItem &other)

ChSystem *	GetSystem () const
	Get the pointer to the parent ChSystem()

virtual void	SetSystem (ChSystem *m_system)
	Set the pointer to the parent ChSystem() and also add to new collision system / remove from old coll.system.

void	AddAsset (std::shared_ptr< ChAsset > masset)
	Add an optional asset (it can be used to define visualization shapes, es ChSphereShape, or textures, or custom attached properties that the user can define by creating his class inherited from ChAsset)

std::vector< std::shared_ptr< ChAsset > > &	GetAssets ()
	Access to the list of optional assets.

std::shared_ptr< ChAsset >	GetAssetN (unsigned int num)
	Access the Nth asset in the list of optional assets.

virtual ChFrame	GetAssetsFrame (unsigned int nclone=0)
	Get the master coordinate system for assets that have some geometric meaning. More...

virtual unsigned int	GetAssetsFrameNclones ()
	Optionally, a ChPhysicsItem can return multiple asset coordinate systems; this can be helpful if, for example, when a ChPhysicsItem contains 'clones' with the same assets (ex. More...

virtual void	GetTotalAABB (ChVector<> &bbmin, ChVector<> &bbmax)
	Get the entire AABB axis-aligned bounding box of the object. More...

virtual void	GetCenter (ChVector<> &mcenter)
	Get a symbolic 'center' of the object. More...

virtual void	StreamINstate (ChStreamInBinary &mstream)
	Method to deserialize only the state (position, speed) Must be implemented by child classes.

virtual void	StreamOUTstate (ChStreamOutBinary &mstream)
	Method to serialize only the state (position, speed) Must be implemented by child classes.

virtual void	Update (bool update_assets=true)
	As above, but does not require updating of time-dependent data. More...

virtual int	GetDOC ()
	Get the number of scalar constraints, if any, in this item.

virtual int	GetDOC_c ()
	Get the number of scalar constraints, if any, in this item (only bilateral constr.) Children classes might override this.

virtual int	GetDOC_d ()
	Get the number of scalar constraints, if any, in this item (only unilateral constr.) Children classes might override this.

unsigned int	GetOffset_x ()
	Get offset in the state vector (position part)

unsigned int	GetOffset_w ()
	Get offset in the state vector (speed part)

unsigned int	GetOffset_L ()
	Get offset in the lagrangian multipliers.

void	SetOffset_x (const unsigned int moff)
	Set offset in the state vector (position part) Note: only the ChSystem::Setup function should use this.

void	SetOffset_w (const unsigned int moff)
	Set offset in the state vector (speed part) Note: only the ChSystem::Setup function should use this.

void	SetOffset_L (const unsigned int moff)
	Set offset in the lagrangian multipliers Note: only the ChSystem::Setup function should use this.

virtual void	IntStateGatherReactions (const unsigned int off_L, ChVectorDynamic<> &L)
	From item's reaction forces to global reaction vector. More...

virtual void	IntStateScatterReactions (const unsigned int off_L, const ChVectorDynamic<> &L)
	From global reaction vector to item's reaction forces. More...

virtual void	IntLoadResidual_CqL (const unsigned int off_L, ChVectorDynamic<> &R, const ChVectorDynamic<> &L, const double c)
	Takes the term Cq'L, scale and adds to R at given offset: R += cCq'*L. More...

virtual void	IntLoadConstraint_C (const unsigned int off, ChVectorDynamic<> &Qc, const double c, bool do_clamp, double recovery_clamp)
	Takes the term C, scale and adds to Qc at given offset: Qc += c*C. More...

virtual void	IntLoadConstraint_Ct (const unsigned int off, ChVectorDynamic<> &Qc, const double c)
	Takes the term Ct, scale and adds to Qc at given offset: Qc += c*Ct. More...

virtual void	InjectConstraints (ChSystemDescriptor &mdescriptor)
	Tell to a system descriptor that there are constraints of type ChConstraint in this object (for further passing it to a solver) Basically does nothing, but maybe that inherited classes may specialize this.

virtual void	ConstraintsBiReset ()
	Sets to zero the known term (b_i) of encapsulated ChConstraints.

virtual void	ConstraintsBiLoad_C (double factor=1, double recovery_clamp=0.1, bool do_clamp=false)
	Adds the current C (constraint violation) to the known term (b_i) of encapsulated ChConstraints.

virtual void	ConstraintsBiLoad_Ct (double factor=1)
	Adds the current Ct (partial t-derivative, as in C_dt=0-> [Cq]*q_dt=-Ct) to the known term (b_i) of encapsulated ChConstraints.

virtual void	ConstraintsBiLoad_Qc (double factor=1)
	Adds the current Qc (the vector of C_dtdt=0 -> [Cq]*q_dtdt=Qc ) to the known term (b_i) of encapsulated ChConstraints.

virtual void	ConstraintsFbLoadForces (double factor=1)
	Adds the current link-forces, if any, (caused by springs, etc.) to the 'fb' vectors of the ChVariables referenced by encapsulated ChConstraints.

virtual void	ConstraintsLoadJacobians ()
	Adds the current jacobians in encapsulated ChConstraints.

virtual void	ConstraintsFetch_react (double factor=1)
	Fetches the reactions from the lagrangian multiplier (l_i) of encapsulated ChConstraints. More...

Public Member Functions inherited from chrono::ChObj
	ChObj (const ChObj &other)

int	GetIdentifier () const
	Gets the numerical identifier of the object.

void	SetIdentifier (int id)
	Sets the numerical identifier of the object.

double	GetChTime () const
	Gets the simulation time of this object.

void	SetChTime (double m_time)
	Sets the simulation time of this object.

const char *	GetName () const
	Gets the name of the object as C Ascii null-terminated string -for reading only!

void	SetName (const char myname[])
	Sets the name of this object, as ascii string.

std::string	GetNameString () const
	Gets the name of the object as C Ascii null-terminated string.

void	SetNameString (const std::string &myname)
	Sets the name of this object, as std::string.

void	MFlagsSetAllOFF (int &mflag)

void	MFlagsSetAllON (int &mflag)

void	MFlagSetON (int &mflag, int mask)

void	MFlagSetOFF (int &mflag, int mask)

int	MFlagGet (int &mflag, int mask)

virtual std::string &	ArchiveContainerName ()

Friends
class	chrono::ChSystem

Additional Inherited Members
Protected Attributes inherited from chrono::ChPhysicsItem
ChSystem *	system
	parent system

std::vector< std::shared_ptr< ChAsset > >	assets
	set of assets

unsigned int	offset_x
	offset in vector of state (position part)

unsigned int	offset_w
	offset in vector of state (speed part)

unsigned int	offset_L
	offset in vector of lagrangian multipliers

Protected Attributes inherited from chrono::ChObj
double	ChTime
	the time of simulation for the object

Member Function Documentation

◆ ComputeMassProperties()

void chrono::fea::ChMesh::ComputeMassProperties	(	double &	mass,
		ChVector<> &	com,
		ChMatrix33<> &	inertia
	)

Get ChMesh mass properties.

Parameters

mass	ChMesh object mass
com	ChMesh center of gravity
inertia	ChMesh inertia tensor

◆ GetDOF()

virtual int chrono::fea::ChMesh::GetDOF ( )

inlineoverridevirtual

Get the number of scalar coordinates (variables), if any, in this item.

Children classes must override this.

Reimplemented from chrono::ChPhysicsItem.

◆ GetDOF_w()

virtual int chrono::fea::ChMesh::GetDOF_w ( )

inlineoverridevirtual

Get the number of scalar coordinates of variables derivatives (usually = DOF, but might be different than DOF, ex.

DOF=4 for quaternions, but DOF_w = 3 for its Lie algebra, ex angular velocity) Children classes might override this.

Reimplemented from chrono::ChPhysicsItem.

◆ IntFromDescriptor()

void chrono::fea::ChMesh::IntFromDescriptor	(	const unsigned int	off_v,
		ChStateDelta &	v,
		const unsigned int	off_L,
		ChVectorDynamic<> &	L
	)

overridevirtual

After a solver solution, fetch values from variables and constraints into vectors:

Parameters

off_v	offset for v
v	vector to where the q 'unknowns' term of the variables will be copied
off_L	offset for L
L	vector to where L 'lagrangian ' term of the constraints will be copied

Reimplemented from chrono::ChPhysicsItem.

◆ IntLoadResidual_F()

void chrono::fea::ChMesh::IntLoadResidual_F	(	const unsigned int	off,
		ChVectorDynamic<> &	R,
		const double	c
	)

overridevirtual

Takes the F force term, scale and adds to R at given offset: R += c*F.

Parameters

off	offset in R residual
R	result: the R residual, R += c*F
c	a scaling factor

Reimplemented from chrono::ChPhysicsItem.

◆ IntLoadResidual_Mv()

void chrono::fea::ChMesh::IntLoadResidual_Mv	(	const unsigned int	off,
		ChVectorDynamic<> &	R,
		const ChVectorDynamic<> &	w,
		const double	c
	)

overridevirtual

Takes the M*v term, multiplying mass by a vector, scale and adds to R at given offset: R += c*M*w.

Parameters

off	offset in R residual
R	result: the R residual, R += cMv
w	the w vector
c	a scaling factor

Reimplemented from chrono::ChPhysicsItem.

◆ IntStateGather()

void chrono::fea::ChMesh::IntStateGather	(	const unsigned int	off_x,
		ChState &	x,
		const unsigned int	off_v,
		ChStateDelta &	v,
		double &	T
	)

overridevirtual

From item's state to global state vectors y={x,v} pasting the states at the specified offsets.

Parameters

off_x	offset in x state vector
x	state vector, position part
off_v	offset in v state vector
v	state vector, speed part
T	time

Reimplemented from chrono::ChPhysicsItem.

◆ IntStateGatherAcceleration()

void chrono::fea::ChMesh::IntStateGatherAcceleration	(	const unsigned int	off_a,
		ChStateDelta &	a
	)

overridevirtual

From item's state acceleration to global acceleration vector.

Parameters

off_a	offset in a accel. vector
a	acceleration part of state vector derivative

Reimplemented from chrono::ChPhysicsItem.

◆ IntStateIncrement()

void chrono::fea::ChMesh::IntStateIncrement	(	const unsigned int	off_x,
		ChState &	x_new,
		const ChState &	x,
		const unsigned int	off_v,
		const ChStateDelta &	Dv
	)

overridevirtual

Computes x_new = x + Dt , using vectors at specified offsets.

By default, when DOF = DOF_w, it does just the sum, but in some cases (ex when using quaternions for rotations) it could do more complex stuff, and children classes might overload it.

Parameters

off_x	offset in x state vector
x_new	state vector, position part, incremented result
x	state vector, initial position part
off_v	offset in v state vector
Dv	state vector, increment

Reimplemented from chrono::ChPhysicsItem.

◆ IntStateScatter()

void chrono::fea::ChMesh::IntStateScatter	(	const unsigned int	off_x,
		const ChState &	x,
		const unsigned int	off_v,
		const ChStateDelta &	v,
		const double	T
	)

overridevirtual

From global state vectors y={x,v} to item's state (and update) fetching the states at the specified offsets.

Parameters

off_x	offset in x state vector
x	state vector, position part
off_v	offset in v state vector
v	state vector, speed part
T	time

Reimplemented from chrono::ChPhysicsItem.

◆ IntStateScatterAcceleration()

void chrono::fea::ChMesh::IntStateScatterAcceleration	(	const unsigned int	off_a,
		const ChStateDelta &	a
	)

overridevirtual

From global acceleration vector to item's state acceleration.

Parameters

off_a	offset in a accel. vector
a	acceleration part of state vector derivative

Reimplemented from chrono::ChPhysicsItem.

◆ IntToDescriptor()

void chrono::fea::ChMesh::IntToDescriptor	(	const unsigned int	off_v,
		const ChStateDelta &	v,
		const ChVectorDynamic<> &	R,
		const unsigned int	off_L,
		const ChVectorDynamic<> &	L,
		const ChVectorDynamic<> &	Qc
	)

overridevirtual

Prepare variables and constraints to accommodate a solution:

Parameters

off_v	offset for v and R
v	vector that will be copied into the q 'unknowns' term of the variables (for warm starting)
R	vector that will be copied into the F 'force' term of the variables
off_L	offset for L and Qc
L	vector that will be copied into the L 'lagrangian ' term of the constraints (for warm starting)
Qc	vector that will be copied into the Qb 'constraint' term of the constraints

Reimplemented from chrono::ChPhysicsItem.

◆ KRMmatricesLoad()

void chrono::fea::ChMesh::KRMmatricesLoad	(	double	Kfactor,
		double	Rfactor,
		double	Mfactor
	)

overridevirtual

Adds the current stiffness K and damping R and mass M matrices in encapsulated ChKblock item(s), if any.

The K, R, M matrices are added with scaling values Kfactor, Rfactor, Mfactor.

Reimplemented from chrono::ChPhysicsItem.

◆ SetAutomaticGravity()

void chrono::fea::ChMesh::SetAutomaticGravity	(	bool	mg,
		int	num_points = `1`
	)

inline

If true, as by default, this mesh will add automatically a gravity load to all contained elements (that support gravity) using the G value from the ChSystem.

So this saves you from adding many ChLoad<ChLoaderGravity> to all elements.

◆ Update()

void chrono::fea::ChMesh::Update	(	double	m_time,
		bool	update_assets = `true`
	)

overridevirtual

Update time dependent data, for all elements.

Updates all [A] coord.systems for all (corotational) elements.

Reimplemented from chrono::ChPhysicsItem.

◆ VariablesFbIncrementMq()

void chrono::fea::ChMesh::VariablesFbIncrementMq ( )

overridevirtual

Adds M*q (masses multiplied current 'qb') to Fb, ex.

if qb is initialized with v_old using VariablesQbLoadSpeed, this method can be used in timestepping schemes that do: M*v_new = M*v_old + forces*dt.

Reimplemented from chrono::ChPhysicsItem.

◆ VariablesQbIncrementPosition()

void chrono::fea::ChMesh::VariablesQbIncrementPosition ( double step )

overridevirtual

Increment item positions by the 'qb' part of the ChVariables, multiplied by a 'step' factor.

    pos += qb * step

If qb is a speed, this behaves like a single step of 1-st order numerical integration (Eulero integration).

Reimplemented from chrono::ChPhysicsItem.

◆ VariablesQbLoadSpeed()

void chrono::fea::ChMesh::VariablesQbLoadSpeed ( )

overridevirtual

Initialize the 'qb' part of the ChVariables with the current value of speeds.

Note: since 'qb' is the unknown, this function seems unnecessary, unless used before VariablesFbIncrementMq().

Reimplemented from chrono::ChPhysicsItem.

◆ VariablesQbSetSpeed()

void chrono::fea::ChMesh::VariablesQbSetSpeed ( double step = 0 )

overridevirtual

Fetches the item speed (ex.

linear and angular vel.in rigid bodies) from the 'qb' part of the ChVariables and sets it as the current item speed. If 'step' is not 0, also should compute the approximate acceleration of the item using backward differences, that is accel=(new_speed-old_speed)/step. Mostly used after the solver provided the solution in ChVariables.

Reimplemented from chrono::ChPhysicsItem.

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

/builds/uwsbel/chrono/src/chrono/fea/ChMesh.h
/builds/uwsbel/chrono/src/chrono/fea/ChMesh.cpp

Description

Public Member Functions

Friends

Additional Inherited Members

Member Function Documentation

◆ ComputeMassProperties()

◆ GetDOF()

◆ GetDOF_w()

◆ IntFromDescriptor()

◆ IntLoadResidual_F()

◆ IntLoadResidual_Mv()

◆ IntStateGather()

◆ IntStateGatherAcceleration()

◆ IntStateIncrement()

◆ IntStateScatter()

◆ IntStateScatterAcceleration()

◆ IntToDescriptor()

◆ KRMmatricesLoad()

◆ SetAutomaticGravity()

◆ Update()

◆ VariablesFbIncrementMq()

◆ VariablesQbIncrementPosition()

◆ VariablesQbLoadSpeed()

◆ VariablesQbSetSpeed()