chrono::fea::ChNodeFEAxyz Class Reference

Description

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

This is the typical node that can be used for tetahedrons, etc.

#include <ChNodeFEAxyz.h>

Inheritance diagram for chrono::fea::ChNodeFEAxyz:
Collaboration diagram for chrono::fea::ChNodeFEAxyz:

Public Member Functions

 ChNodeFEAxyz (ChVector<> initial_pos=VNULL)
 
 ChNodeFEAxyz (const ChNodeFEAxyz &other)
 
ChNodeFEAxyzoperator= (const ChNodeFEAxyz &other)
 
virtual ChVariablesNodeVariables () override
 
virtual void Relax () override
 Set the rest position as the actual position.
 
virtual void SetNoSpeedNoAcceleration () override
 Reset to no speed and acceleration.
 
virtual void SetFixed (bool mev) override
 Set the 'fixed' state of the node. More...
 
virtual bool GetFixed () override
 Get the 'fixed' state of the node. More...
 
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 int Get_ndof_x () const override
 Get the number of degrees of freedom.
 
virtual ChVariablesGetVariables1 () override
 
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. More...
 
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 void ArchiveOUT (ChArchiveOut &marchive) override
 
virtual void ArchiveIN (ChArchiveIn &marchive) override
 Method to allow de serialization of transient data from archives.
 
- 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)
 
ChNodeBaseoperator= (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. More...
 
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)
 
ChNodeXYZoperator= (const ChNodeXYZ &other)
 
const ChVectorGetPos () const
 
void SetPos (const ChVector<> &mpos)
 
const ChVectorGetPos_dt () const
 
void SetPos_dt (const ChVector<> &mposdt)
 
const ChVectorGetPos_dtdt () const
 
void SetPos_dtdt (const ChVector<> &mposdtdt)
 
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 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 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 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 quadrature over u,v,w in [-1..+1] as box isoparametric coords. More...
 

Protected Attributes

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)
 

Additional Inherited Members

- Public Types inherited from chrono::ChVariableTupleCarrier_1vars< 3 >
typedef
ChConstraintTuple_1vars
< ChVariableTupleCarrier_1vars
< N1 > > 
type_constraint_tuple
 
- 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
 
- Static Public Attributes inherited from chrono::ChVariableTupleCarrier_1vars< 3 >
static const int nvars1
 

Member Function Documentation

virtual bool chrono::fea::ChNodeFEAxyz::GetFixed ( )
overridevirtual

Get the 'fixed' state of the node.

If true, its current field value is not changed by solver.

Implements chrono::fea::ChNodeFEAbase.

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

virtual void chrono::fea::ChNodeFEAxyz::SetFixed ( bool  mev)
overridevirtual

Set the 'fixed' state of the node.

If true, its current field value is not changed by solver.

Implements chrono::fea::ChNodeFEAbase.

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

virtual void chrono::fea::ChNodeFEAxyz::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::ChNodeBase.

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

virtual void chrono::fea::ChNodeFEAxyz::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::ChNodeBase.

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

virtual void chrono::fea::ChNodeFEAxyz::VariablesQbLoadSpeed ( )
overridevirtual

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

Reimplemented from chrono::ChNodeBase.

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

virtual void chrono::fea::ChNodeFEAxyz::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::ChNodeBase.

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

Member Data Documentation

ChVector chrono::fea::ChNodeFEAxyz::X0
protected

3D node variables, with x,y,z

reference position