Description

Class for a generic 3D finite element node, with x,y,z displacement and a direction.

The direction D represents a gradient vector to be used in ANCF elements.

#include <ChNodeFEAxyzD.h>

Inheritance diagram for chrono::fea::ChNodeFEAxyzD:

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Collaboration diagram for chrono::fea::ChNodeFEAxyzD:

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Public Member Functions
	ChNodeFEAxyzD (ChVector<> initial_pos=VNULL, ChVector<> initial_dir=VECT_X)

	ChNodeFEAxyzD (const ChNodeFEAxyzD &other)

ChNodeFEAxyzD &	operator= (const ChNodeFEAxyzD &other)

void	SetD (ChVector<> mD)
	Set the direction.

const ChVector &	GetD () const
	Get the direction.

void	SetD_dt (ChVector<> mD)
	Set the direction speed.

const ChVector &	GetD_dt () const
	Get the direction speed.

void	SetD_dtdt (ChVector<> mD)
	Set the direction acceleration.

const ChVector &	GetD_dtdt () const
	Get the direction acceleration.

ChVariables &	Variables_D ()

virtual void	SetNoSpeedNoAcceleration () override
	Reset to no speed and acceleration.

virtual ChVectorDynamic &	GetMassDiagonal ()
	Get mass of the node.

virtual void	SetFixed (bool mev) override
	Sets the 'fixed' state of the node. More...

virtual bool	GetFixed () override
	Gets the 'fixed' state of the node.

virtual int	Get_ndof_x () const override
	Get the number of degrees of freedom.

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

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

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

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

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

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

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

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

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

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)

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 node) 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.

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

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

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

virtual int	LoadableGet_ndof_x () override
	Gets the number of DOFs affected by this element (position part)

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

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

virtual void	LoadableGetStateBlock_w (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.

virtual int	Get_field_ncoords () override
	Number of coordinates in the interpolated field, ex=3 for a tetrahedron finite element or a cable, etc. More...

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

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

virtual void	ComputeNF (const double U, const double V, const double W, ChVectorDynamic<> &Qi, double &detJ, const ChVectorDynamic<> &F, ChVectorDynamic<> state_x, ChVectorDynamic<> state_w) override
	Evaluate Q=N'*F , for Q generalized lagrangian load, where N is some type of matrix evaluated at point P(U,V,W) assumed in absolute coordinates, and F is a load assumed in absolute coordinates. More...

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

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

Public Member Functions inherited from chrono::fea::ChNodeFEAxyz
	ChNodeFEAxyz (ChVector<> initial_pos=VNULL)

	ChNodeFEAxyz (const ChNodeFEAxyz &other)

ChNodeFEAxyz &	operator= (const ChNodeFEAxyz &other)

virtual ChVariablesNode &	Variables () override

virtual void	Relax () override
	Set the rest position as the actual position.

virtual double	GetMass () const override
	Get mass of the node.

virtual void	SetMass (double mm) override
	Set mass of the node.

virtual void	SetX0 (ChVector<> mx)
	Set the initial (reference) position.

virtual ChVector	GetX0 ()
	Get the initial (reference) position.

virtual void	SetForce (ChVector<> mf)
	Set the 3d applied force, in absolute reference.

virtual ChVector	GetForce ()
	Get the 3d applied force, in absolute reference.

virtual ChVariables *	GetVariables1 () override

Public Member Functions inherited from chrono::fea::ChNodeFEAbase
virtual void	SetIndex (unsigned int mindex)
	Sets the global index of the node.

virtual unsigned int	GetIndex ()
	Gets the global index of the node.

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

ChNodeBase &	operator= (const ChNodeBase &other)

virtual int	Get_ndof_w () const
	Get the number of degrees of freedom, derivative This might be different from ndof if quaternions are used for rotations, as derivative might be angular velocity.

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

unsigned int	NodeGetOffset_w ()
	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)

Public Member Functions inherited from chrono::ChNodeXYZ
	ChNodeXYZ (const ChVector<> &initial_pos)

	ChNodeXYZ (const ChNodeXYZ &other)

ChNodeXYZ &	operator= (const ChNodeXYZ &other)

const ChVector &	GetPos () const

void	SetPos (const ChVector<> &mpos)

const ChVector &	GetPos_dt () const

void	SetPos_dt (const ChVector<> &mposdt)

const ChVector &	GetPos_dtdt () const

void	SetPos_dtdt (const ChVector<> &mposdtdt)

virtual int	GetSubBlocks () override
	Tell the number of DOFs blocks (ex. =1 for a body, =4 for a tetrahedron, etc.)

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

virtual double	GetDensity () override
	This is not needed because not used in quadrature.

Public Member Functions inherited from chrono::ChLoadableUVW
virtual bool	IsTetrahedronIntegrationNeeded ()
	If true, use quadrature over u,v,w in [0..1] range as tetrahedron volumetric coords (with z=1-u-v-w) otherwise use default quadrature over u,v,w in [-1..+1] as box isoparametric coords.

virtual bool	IsTrianglePrismIntegrationNeeded ()
	If true, use quadrature over u,v in [0..1] range as triangle natural coords (with z=1-u-v), and use linear quadrature over w in [-1..+1], otherwise use default quadrature over u,v,w in [-1..+1] as box isoparametric coords.

Public Attributes
ChVector	D

ChVector	D_dt

ChVector	D_dtdt

Public Attributes inherited from chrono::fea::ChNodeFEAbase
double	m_TotalMass
	Nodal mass obtained from element masss matrix.

Public Attributes inherited from chrono::ChNodeXYZ
ChVector	pos

ChVector	pos_dt

ChVector	pos_dtdt

Additional Inherited Members
Public Types inherited from chrono::ChVariableTupleCarrier_1vars< 3 >
typedef ChConstraintTuple_1vars< ChVariableTupleCarrier_1vars< N1 > >	type_constraint_tuple

Static Public Attributes inherited from chrono::ChVariableTupleCarrier_1vars< 3 >
static const int	nvars1

Protected Attributes inherited from chrono::fea::ChNodeFEAxyz
ChVariablesNode	variables

ChVector	X0
	3D node variables, with x,y,z More...

ChVector	Force
	applied force

Protected Attributes inherited from chrono::fea::ChNodeFEAbase
unsigned int	g_index
	global node index

Protected Attributes inherited from chrono::ChNodeBase
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

◆ ComputeNF()

void chrono::fea::ChNodeFEAxyzD::ComputeNF	(	const double	U,
		const double	V,
		const double	W,
		ChVectorDynamic<> &	Qi,
		double &	detJ,
		const ChVectorDynamic<> &	F,
		ChVectorDynamic<> *	state_x,
		ChVectorDynamic<> *	state_w
	)

overridevirtual

Evaluate Q=N'*F , for Q generalized lagrangian load, where N is some type of matrix evaluated at point P(U,V,W) assumed in absolute coordinates, and F is a load assumed in absolute coordinates.

The det[J] is unused.

Parameters

U	x coordinate of application point in absolute space
V	y coordinate of application point in absolute space
W	z coordinate of application point in absolute space
Qi	Return result of N'*F here, maybe with offset block_offset
detJ	Return det[J] here
F	Input F vector, containing Force xyz in absolute coords and a 'pseudo' torque.
state_x	if != 0, update state (pos. part) to this, then evaluate Q
state_w	if != 0, update state (speed part) to this, then evaluate Q

Reimplemented from chrono::ChNodeXYZ.

Reimplemented in chrono::fea::ChNodeFEAxyzDD.

◆ Get_field_ncoords()

virtual int chrono::fea::ChNodeFEAxyzD::Get_field_ncoords ( )

inlineoverridevirtual

Number of coordinates in the interpolated field, ex=3 for a tetrahedron finite element or a cable, etc.

Here is 6: xyz displ + xyz rots

Reimplemented from chrono::ChNodeXYZ.

Reimplemented in chrono::fea::ChNodeFEAxyzDD.

◆ SetFixed()

void chrono::fea::ChNodeFEAxyzD::SetFixed ( bool mev )

overridevirtual

Sets the 'fixed' state of the node.

If true, it does not move respect to the absolute world, despite constraints, forces, etc.

Reimplemented from chrono::fea::ChNodeFEAxyz.

Reimplemented in chrono::fea::ChNodeFEAxyzDD.

◆ VariablesFbIncrementMq()

void chrono::fea::ChNodeFEAxyzD::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::fea::ChNodeFEAxyz.

Reimplemented in chrono::fea::ChNodeFEAxyzDD.

◆ VariablesQbIncrementPosition()

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

overridevirtual

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 from chrono::fea::ChNodeFEAxyz.

Reimplemented in chrono::fea::ChNodeFEAxyzDD.

◆ VariablesQbSetSpeed()

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

overridevirtual

Fetches 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 from chrono::fea::ChNodeFEAxyz.

Reimplemented in chrono::fea::ChNodeFEAxyzDD.

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

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

Description

Public Member Functions

Public Attributes

Additional Inherited Members

Member Function Documentation

◆ ComputeNF()

◆ Get_field_ncoords()

◆ SetFixed()

◆ VariablesFbIncrementMq()

◆ VariablesQbIncrementPosition()

◆ VariablesQbSetSpeed()