Description

Class for one-degree-of-freedom mechanical parts with associated inertia (mass or moment of rotational inertia).

In most cases these represent shafts that can be used to build 1D models of power trains. This is more efficient than simulating power trains modeled with full 3D ChBody objects.

#include <ChShaft.h>

Inheritance diagram for chrono::ChShaft:

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Collaboration diagram for chrono::ChShaft:

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Public Member Functions
	ChShaft (const ChShaft &other)

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

void	ForceToRest () override
	Set no speed and no accelerations (but does not change the position)

void	SetAppliedLoad (double applied_load)
	Set the load applied to the shaft. More...

double	GetAppliedLoad () const
	Get the load applied to the shaft. More...

void	SetPos (double mp)
	Set the shaft position. More...

double	GetPos () const
	Get the shaft position. More...

void	SetPosDt (double mp)
	Set the shaft velocity. More...

double	GetPosDt () const
	Get the shaft velocity. More...

void	SetPosDt2 (double mp)
	Set the shaft acceleration. More...

double	GetPosDt2 () const
	Get the shaft acceleration. More...

void	SetInertia (double newJ)
	Inertia property of the shaft (must be a positive value). More...

double	GetInertia () const
	Get the shaft inertia property.

void	SetMaxSpeed (float m_max_speed)
	Set the maximum shaft speed (beyond this limit, the speed it will be clamped).

void	ClampSpeed ()
	Clamp the shaft speed shaft is clamped to the range specified by SetMaxSpeed. More...

void	SetSleepTime (float time)
	Set the duration before automatically placing the shaft in sleep mode when shaft movement is small.

void	SetSleepMinSpeed (float speed)
	Set the max linear speed to be kept for 'sleep_time' before freezing.

void	SetFixed (bool fixed)
	Fix or release this shaft. More...

bool	IsFixed () const
	Return true if the shaft is set to fixed.

void	SetLimitSpeed (bool limit)
	Enable limit on shaft speed (default: false).

void	SetSleepingAllowed (bool sleeping)
	If use sleeping= true, shafts which do not rotate for too long time will be deactivated, for optimization. More...

bool	IsSleepingAllowed () const
	Return true if this shaft is allowed to go to sleep.

void	SetSleeping (bool ms)
	Force the shaft in sleeping mode or not. More...

bool	IsSleeping () const
	Tell if the shaft is actually in sleeping state.

bool	TrySleeping ()
	Put the shaft in sleeping state if requirements are satisfied.

virtual bool	IsActive () const override
	Return true if the shaft is currently active and thereofre included into the system solver. More...

ChVariablesShaft &	Variables ()
	Returns reference to the encapsulated ChVariables,.

virtual void	ArchiveOut (ChArchiveOut &archive_out) override
	Method to allow serialization of transient data to archives.

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

unsigned int	GetIndex () const
	Get the unique sequential shaft index (internal use only).

virtual unsigned int	GetNumCoordsPosLevel () override
	Number of coordinates of the shaft.

virtual void	InjectVariables (ChSystemDescriptor &descriptor) override
	Register with the given system descriptor any ChVariable objects associated with this item.

virtual void	Update (double mytime, bool update_assets=true) override
	Perform any updates necessary at the current phase during the solution process. 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, bool full_update) 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	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	IntLoadLumpedMass_Md (const unsigned int off, ChVectorDynamic<> &Md, double &err, const double c) override
	Adds the lumped mass to a Md vector, representing a mass diagonal matrix. 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	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 unsigned int	GetLoadableNumCoordsPosLevel () override
	Gets the number of DOFs affected by this element (position part)

virtual unsigned int	GetLoadableNumCoordsVelLevel () override
	Gets the number of DOFs affected by this element (speed part)

virtual void	LoadableGetStateBlockPosLevel (int block_offset, ChState &mD) override
	Gets all the DOFs packed in a single vector (position part)

virtual void	LoadableGetStateBlockVelLevel (int block_offset, ChStateDelta &mD) override
	Gets all the DOFs packed in a single vector (speed part)

virtual void	LoadableStateIncrement (const unsigned int off_x, ChState &x_new, const ChState &x, const unsigned int off_v, const ChStateDelta &Dv) override
	Increment all DOFs using a delta. More...

virtual unsigned int	GetNumFieldCoords () override
	Number of coordinates in the interpolated field (e.g., 3 for a tetrahedron, 1 for a thermal problem, etc.).

virtual unsigned int	GetNumSubBlocks () override
	Get the number of DOFs sub-blocks (e.g., 1 for a body, 4 for a tetrahedron, etc.).

virtual unsigned int	GetSubBlockOffset (unsigned int nblock) override
	Get the offset of the specified sub-block of DOFs in global vector.

virtual unsigned int	GetSubBlockSize (unsigned int nblock) override
	Get the size of the specified sub-block of DOFs in global vector.

virtual bool	IsSubBlockActive (unsigned int nblock) const override
	Check if the specified sub-block of DOFs is active.

virtual void	LoadableGetVariables (std::vector< ChVariables * > &mvars) override
	Get the pointers to the contained ChVariables, appending to the mvars vector.

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(). More...

void	AddVisualModel (std::shared_ptr< ChVisualModel > model)
	Add an (optional) visualization model. More...

std::shared_ptr< ChVisualModel >	GetVisualModel () const
	Access the visualization model (if any). More...

void	AddVisualShape (std::shared_ptr< ChVisualShape > shape, const ChFrame<> &frame=ChFrame<>())
	Add the specified visual shape to the visualization model. More...

std::shared_ptr< ChVisualShape >	GetVisualShape (unsigned int i) const
	Access the specified visualization shape in the visualization model (if any). More...

void	AddVisualShapeFEA (std::shared_ptr< ChVisualShapeFEA > shapeFEA)
	Add the specified FEA visualization object to the visualization model. More...

std::shared_ptr< ChVisualShapeFEA >	GetVisualShapeFEA (unsigned int i) const
	Access the specified FEA visualization object in the visualization model (if any). More...

virtual ChFrame	GetVisualModelFrame (unsigned int nclone=0) const
	Get the reference frame (expressed in and relative to the absolute frame) of the visual model. More...

virtual unsigned int	GetNumVisualModelClones () const
	Return the number of clones of the visual model associated with this physics item. More...

void	AddCamera (std::shared_ptr< ChCamera > camera)
	Attach a ChCamera to this physical item. More...

std::vector< std::shared_ptr< ChCamera > >	GetCameras () const
	Get the set of cameras attached to this physics item.

virtual bool	IsCollisionEnabled () const
	Tell if the object is subject to collision. More...

virtual void	AddCollisionModelsToSystem (ChCollisionSystem *coll_sys) const
	Add to the provided collision system any collision models managed by this physics item. More...

virtual void	RemoveCollisionModelsFromSystem (ChCollisionSystem *coll_sys) const
	Remove from the provided collision system any collision models managed by this physics item. More...

virtual void	SyncCollisionModels ()
	Synchronize the position and bounding box of any collsion models managed by this physics item.

virtual ChAABB	GetTotalAABB () const
	Get the axis-aligned bounding box (AABB) of this object. More...

virtual ChVector3d	GetCenter () const
	Get a symbolic 'center' of the object. More...

virtual void	Setup ()
	Perform setup operations. More...

virtual void	Update (bool update_assets=true)
	Perform an update using the current time.

void	UpdateVisualModel ()
	Utility function to update only the associated visual assets (if any).

virtual unsigned int	GetNumCoordsVelLevel ()
	Get the number of coordinates at the velocity level. More...

virtual unsigned int	GetNumConstraints ()
	Get the number of scalar constraints.

virtual unsigned int	GetNumConstraintsBilateral ()
	Get the number of bilateral scalar constraints.

virtual unsigned int	GetNumConstraintsUnilateral ()
	Get the number of unilateral scalar constraints.

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

virtual void	IntStateGetIncrement (const unsigned int off_x, const ChState &x_new, const ChState &x, const unsigned int off_v, ChStateDelta &Dv)
	Computes Dt = x_new - x, using vectors at specified offsets. 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 &descriptor)
	Register with the given system descriptor any ChConstraint objects associated with this item.

virtual void	LoadConstraintJacobians ()
	Compute and load current Jacobians in encapsulated ChConstraint objects.

virtual void	InjectKRMMatrices (ChSystemDescriptor &descriptor)
	Register with the given system descriptor any ChKRMBlock objects associated with this item.

virtual void	LoadKRMMatrices (double Kfactor, double Rfactor, double Mfactor)
	Compute and load current stiffnes (K), damping (R), and mass (M) matrices in encapsulated ChKRMBlock objects. More...

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	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
	Get the unique integer identifier of this object. More...

void	SetTag (int tag)
	Set an object integer tag (default: -1). More...

int	GetTag () const
	Get the tag of this object.

void	SetName (const std::string &myname)
	Set the name of this object.

const std::string &	GetName () const
	Get the name of this object.

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

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

virtual std::string &	ArchiveContainerName ()

Friends
class	ChSystem

class	ChSystemMulticore

Additional Inherited Members
Protected Member Functions inherited from chrono::ChObj
int	GenerateUniqueIdentifier ()

Protected Attributes inherited from chrono::ChPhysicsItem
ChSystem *	system
	parent system

std::shared_ptr< ChVisualModelInstance >	vis_model_instance
	instantiated visualization model

std::vector< std::shared_ptr< ChCamera > >	cameras
	set of cameras

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
	object simulation time

std::string	m_name
	object name

int	m_identifier
	object unique identifier

int	m_tag
	user-supplied tag

Member Function Documentation

◆ ClampSpeed()

void chrono::ChShaft::ClampSpeed ( )

Clamp the shaft speed shaft is clamped to the range specified by SetMaxSpeed.

The speed limit must be enabled (i.e., call first SetLimitSpeed(true)).

◆ GetAppliedLoad()

double chrono::ChShaft::GetAppliedLoad ( ) const

inline

Get the load applied to the shaft.

For shafts with a rotational degree of freedom, this represents the applied torque. For shafts with a translational degree of freedom, this is the applied force.

◆ GetPos()

double chrono::ChShaft::GetPos ( ) const

inline

Get the shaft position.

For shafts with a rotational degree of freedom, this represents an angle. For shafts with a translational degree of freedom, this represents a displacement.

◆ GetPosDt()

double chrono::ChShaft::GetPosDt ( ) const

inline

Get the shaft velocity.

For shafts with a rotational degree of freedom, this represents an angular velocity. For shafts with a translational degree of freedom, this represents a linear velocity.

◆ GetPosDt2()

double chrono::ChShaft::GetPosDt2 ( ) const

inline

Get the shaft acceleration.

For shafts with a rotational degree of freedom, this represents an angular acceleration. For shafts with a translational degree of freedom, this represents a linear acceleration.

◆ IntFromDescriptor()

void chrono::ChShaft::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.

◆ IntLoadLumpedMass_Md()

void chrono::ChShaft::IntLoadLumpedMass_Md	(	const unsigned int	off,
		ChVectorDynamic<> &	Md,
		double &	err,
		const double	c
	)

overridevirtual

Adds the lumped mass to a Md vector, representing a mass diagonal matrix.

Used by lumped explicit integrators. If mass lumping is impossible or approximate, adds scalar error to "error" parameter. Md += c*diag(M)

Parameters

off	offset in Md vector
Md	result: Md vector, diagonal of the lumped mass matrix
err	result: not touched if lumping does not introduce errors
c	a scaling factor

Reimplemented from chrono::ChPhysicsItem.

◆ IntLoadResidual_F()

void chrono::ChShaft::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::ChShaft::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::ChShaft::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::ChShaft::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.

◆ IntStateScatter()

void chrono::ChShaft::IntStateScatter	(	const unsigned int	off_x,
		const ChState &	x,
		const unsigned int	off_v,
		const ChStateDelta &	v,
		const double	T,
		bool	full_update
	)

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
full_update	perform complete update

Reimplemented from chrono::ChPhysicsItem.

◆ IntStateScatterAcceleration()

void chrono::ChShaft::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::ChShaft::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 copied into the q 'unknowns' term of the variables
R	vector copied into the F 'force' term of the variables
off_L	offset for L and Qc
L	vector copied into the L 'lagrangian ' term of the constraints
Qc	vector copied into the Qb 'constraint' term of the constraints

Reimplemented from chrono::ChPhysicsItem.

◆ IsActive()

virtual bool chrono::ChShaft::IsActive ( ) const

inlineoverridevirtual

Return true if the shaft is currently active and thereofre included into the system solver.

A shaft is inactive if it is fixed to ground or is in sleep mode.

Reimplemented from chrono::ChPhysicsItem.

◆ LoadableStateIncrement()

virtual void chrono::ChShaft::LoadableStateIncrement	(	const unsigned int	off_x,
		ChState &	x_new,
		const ChState &	x,
		const unsigned int	off_v,
		const ChStateDelta &	Dv
	)

inlineoverridevirtual

Increment all DOFs using a delta.

Default is sum, but may override if ndof_x is different than ndof_w, for example with rotation quaternions and angular w vel. This could be invoked, for example, by the BDF differentiation that computes the jacobians.

Implements chrono::ChLoadable.

◆ SetAppliedLoad()

void chrono::ChShaft::SetAppliedLoad ( double applied_load )

inline

Set the load applied to the shaft.

For shafts with a rotational degree of freedom, this represents the applied torque. For shafts with a translational degree of freedom, this is the applied force.

◆ SetFixed()

void chrono::ChShaft::SetFixed ( bool fixed )

Fix or release this shaft.

If set to true, the shaft does not move, regardless of applied loads.

◆ SetInertia()

void chrono::ChShaft::SetInertia ( double newJ )

Inertia property of the shaft (must be a positive value).

For rotational shafts, this is a moment of inertia. For translational shafts, this is a mass. Try not to mix physics items with too widely different inertia values, for numerical stability.

◆ SetPos()

void chrono::ChShaft::SetPos ( double mp )

inline

Set the shaft position.

For shafts with a rotational degree of freedom, this represents an angle. For shafts with a translational degree of freedom, this represents a displacement.

◆ SetPosDt()

void chrono::ChShaft::SetPosDt ( double mp )

inline

Set the shaft velocity.

For shafts with a rotational degree of freedom, this represents an angular velocity. For shafts with a translational degree of freedom, this represents a linear velocity.

◆ SetPosDt2()

void chrono::ChShaft::SetPosDt2 ( double mp )

inline

Set the shaft acceleration.

For shafts with a rotational degree of freedom, this represents an angular acceleration. For shafts with a translational degree of freedom, this represents a linear acceleration.

◆ SetSleeping()

void chrono::ChShaft::SetSleeping ( bool ms )

inline

Force the shaft in sleeping mode or not.

Note: Usually this state change is not handled by users, because it is mostly automatic.

◆ SetSleepingAllowed()

void chrono::ChShaft::SetSleepingAllowed ( bool sleeping )

inline

If use sleeping= true, shafts which do not rotate for too long time will be deactivated, for optimization.

The realism is limited, but the simulation is faster.

◆ Update()

void chrono::ChShaft::Update	(	double	time,
		bool	update_assets = `true`
	)

overridevirtual

Perform any updates necessary at the current phase during the solution process.

This function is called at least once per step to update auxiliary data, internal states, etc. The default implementation updates the item's time stamp and its visualization assets (if any are defined anf only if requested).

Reimplemented from chrono::ChPhysicsItem.

◆ VariablesFbIncrementMq()

void chrono::ChShaft::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::ChShaft::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 (Euler integration).

Reimplemented from chrono::ChPhysicsItem.

◆ VariablesQbLoadSpeed()

void chrono::ChShaft::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::ChShaft::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/physics/ChShaft.h
/builds/uwsbel/chrono/src/chrono/physics/ChShaft.cpp

Description

Public Member Functions

Friends

Additional Inherited Members

Member Function Documentation

◆ ClampSpeed()

◆ GetAppliedLoad()

◆ GetPos()

◆ GetPosDt()

◆ GetPosDt2()

◆ IntFromDescriptor()

◆ IntLoadLumpedMass_Md()

◆ IntLoadResidual_F()

◆ IntLoadResidual_Mv()

◆ IntStateGather()

◆ IntStateGatherAcceleration()

◆ IntStateScatter()

◆ IntStateScatterAcceleration()

◆ IntToDescriptor()

◆ IsActive()

◆ LoadableStateIncrement()

◆ SetAppliedLoad()

◆ SetFixed()

◆ SetInertia()

◆ SetPos()

◆ SetPosDt()

◆ SetPosDt2()

◆ SetSleeping()

◆ SetSleepingAllowed()

◆ Update()

◆ VariablesFbIncrementMq()

◆ VariablesQbIncrementPosition()

◆ VariablesQbLoadSpeed()

◆ VariablesQbSetSpeed()