Description

Class for a node, that has some degrees of freedom.

It is like a lightweight version of a ChPhysicsItem; often a ChPhysicsItem is used as a container for a cluster of these ChNodeBase.

#include <ChNodeBase.h>

Inheritance diagram for chrono::ChNodeBase:

[legend]

Public Member Functions
	ChNodeBase (const ChNodeBase &other)

ChNodeBase &	operator= (const ChNodeBase &other)

virtual int	GetNdofX () const =0
	Get the number of degrees of freedom.

virtual int	GetNdofW () const
	Get the number of degrees of freedom, derivative. More...

virtual int	GetNdofX_active () const
	Get the actual number of active degrees of freedom. More...

virtual int	GetNdofW_active () const
	Get the actual number of active degrees of freedom, derivative. More...

virtual bool	UseFullDof () const
	Return true if all node DOFs are active (no node variable is fixed).

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

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

void	NodeSetOffset_x (const unsigned int moff)
	Set offset in the state vector (position part).

void	NodeSetOffset_w (const unsigned int moff)
	Set offset in the state vector (speed part).

virtual void	NodeIntStateGather (const unsigned int off_x, ChState &x, const unsigned int off_v, ChStateDelta &v, double &T)

virtual void	NodeIntStateScatter (const unsigned int off_x, const ChState &x, const unsigned int off_v, const ChStateDelta &v, const double T)

virtual void	NodeIntStateGatherAcceleration (const unsigned int off_a, ChStateDelta &a)

virtual void	NodeIntStateScatterAcceleration (const unsigned int off_a, const ChStateDelta &a)

virtual void	NodeIntStateIncrement (const unsigned int off_x, ChState &x_new, const ChState &x, const unsigned int off_v, const ChStateDelta &Dv)

virtual void	NodeIntStateGetIncrement (const unsigned int off_x, const ChState &x_new, const ChState &x, const unsigned int off_v, ChStateDelta &Dv)

virtual void	NodeIntLoadResidual_F (const unsigned int off, ChVectorDynamic<> &R, const double c)

virtual void	NodeIntLoadResidual_Mv (const unsigned int off, ChVectorDynamic<> &R, const ChVectorDynamic<> &w, const double c)

virtual void	NodeIntToDescriptor (const unsigned int off_v, const ChStateDelta &v, const ChVectorDynamic<> &R)

virtual void	NodeIntFromDescriptor (const unsigned int off_v, ChStateDelta &v)

virtual void	InjectVariables (ChSystemDescriptor &mdescriptor)
	Tell to a system descriptor that there are variables of type ChVariables in this object (for further passing it to a solver).

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

virtual void	VariablesFbLoadForces (double factor=1)
	Add the current forces (applied to node) into the encapsulated ChVariables. More...

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

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

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

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

virtual void	ArchiveOUT (ChArchiveOut &marchive)
	Method to allow serialization of transient data to archives.

virtual void	ArchiveIN (ChArchiveIn &marchive)
	Method to allow de-serialization of transient data from archives.

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

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

Member Function Documentation

◆ GetNdofW()

virtual int chrono::ChNodeBase::GetNdofW ( ) const

inlinevirtual

Get the number of degrees of freedom, derivative.

This might be different from ndof_x if quaternions are used for rotations and derivative is angular velocity.

Reimplemented in chrono::fea::ChNodeFEAcurv, and chrono::fea::ChNodeFEAxyzrot.

◆ GetNdofW_active()

virtual int chrono::ChNodeBase::GetNdofW_active ( ) const

inlinevirtual

Get the actual number of active degrees of freedom, derivative.

The default implementation returns the full number of DOFs for this node, but derived classes may allow fixing some of the node variables.

◆ GetNdofX_active()

virtual int chrono::ChNodeBase::GetNdofX_active ( ) const

inlinevirtual

Get the actual number of active degrees of freedom.

The default implementation returns the full number of DOFs for this node, but derived classes may allow fixing some of the node variables.

Reimplemented in chrono::fea::ChNodeFEAxyzDDD, chrono::fea::ChNodeFEAxyzDD, and chrono::fea::ChNodeFEAxyzD.

◆ VariablesFbIncrementMq()

virtual void chrono::ChNodeBase::VariablesFbIncrementMq ( )

inlinevirtual

Add 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 in chrono::fea::ChNodeFEAcurv, chrono::fea::ChNodeFEAxyzrot, chrono::fea::ChNodeFEAxyzDDD, chrono::fea::ChNodeFEAxyzDD, chrono::fea::ChNodeFEAxyzD, chrono::fea::ChNodeFEAxyz, and chrono::fea::ChNodeFEAxyzP.

◆ VariablesFbLoadForces()

virtual void chrono::ChNodeBase::VariablesFbLoadForces ( double factor = 1 )

inlinevirtual

Add the current forces (applied to node) into the encapsulated ChVariables.

Include in the 'fb' part: qf+=forces*factor

Reimplemented in chrono::fea::ChNodeFEAcurv, chrono::fea::ChNodeFEAxyzrot, chrono::fea::ChNodeFEAxyzDDD, chrono::fea::ChNodeFEAxyzDD, chrono::fea::ChNodeFEAxyzD, chrono::fea::ChNodeFEAxyz, and chrono::fea::ChNodeFEAxyzP.

◆ VariablesQbIncrementPosition()

virtual void chrono::ChNodeBase::VariablesQbIncrementPosition ( double step )

inlinevirtual

Increment node 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 in chrono::fea::ChNodeFEAcurv, chrono::fea::ChNodeFEAxyzrot, chrono::fea::ChNodeFEAxyzDDD, chrono::fea::ChNodeFEAxyzDD, chrono::fea::ChNodeFEAxyzD, chrono::fea::ChNodeFEAxyz, and chrono::fea::ChNodeFEAxyzP.

◆ VariablesQbSetSpeed()

virtual void chrono::ChNodeBase::VariablesQbSetSpeed ( double step = 0 )

inlinevirtual

Fetch the item speed (ex.

linear velocity, in xyz nodes) 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 in chrono::fea::ChNodeFEAcurv, chrono::fea::ChNodeFEAxyzrot, chrono::fea::ChNodeFEAxyzDDD, chrono::fea::ChNodeFEAxyzDD, chrono::fea::ChNodeFEAxyzD, chrono::fea::ChNodeFEAxyz, and chrono::fea::ChNodeFEAxyzP.

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

/builds/uwsbel/chrono/src/chrono/physics/ChNodeBase.h
/builds/uwsbel/chrono/src/chrono/physics/ChNodeBase.cpp

Description

Public Member Functions

Protected Attributes

Member Function Documentation

◆ GetNdofW()

◆ GetNdofW_active()

◆ GetNdofX_active()

◆ VariablesFbIncrementMq()

◆ VariablesFbLoadForces()

◆ VariablesQbIncrementPosition()

◆ VariablesQbSetSpeed()