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itk::fem::Element3DC0LinearHexahedron Class Reference

8-noded, linear, C0 continuous finite element in 3D space. More...

#include <itkFEMElement3DC0LinearHexahedron.h>

Inheritance diagram for itk::fem::Element3DC0LinearHexahedron:

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List of all members.

Public Types

enum  { InvalidDegreeOfFreedomID = 0xffffffff }
enum  { gaussMaxOrder = 10 }
enum  
enum  
enum  
typedef FEMPArray< ElementArrayType
typedef Self Baseclass
typedef const SelfConstPointer
typedef
Superclass::DegreeOfFreedomIDType 
DegreeOfFreedomIDType
typedef Superclass::Float Float

Public Member Functions

virtual int ClassID () const =0
virtual Baseclass::Pointer Clone () const =0
virtual Float GetElementDeformationEnergy (MatrixType &LocalSolution) const
virtual VectorType GetGlobalFromLocalCoordinates (const VectorType &pt) const
virtual void GetIntegrationPointAndWeight (unsigned int i, VectorType &pt, Float &w, unsigned int order) const
virtual void GetLandmarkContributionMatrix (float eta, MatrixType &Le) const
virtual void GetLoadVector (LoadPointer l, VectorType &Fe) const =0
virtual bool GetLocalFromGlobalCoordinates (const VectorType &globalPt, VectorType &localPt) const
virtual void GetMassMatrix (MatrixType &Me) const
virtual Material::ConstPointer GetMaterial (void) const
virtual void GetMaterialMatrix (MatrixType &D) const =0
virtual NodeIDType GetNode (unsigned int n) const
virtual const VectorTypeGetNodeCoordinates (unsigned int n) const
virtual unsigned int GetNumberOfDegreesOfFreedom (void) const
virtual unsigned int GetNumberOfDegreesOfFreedomPerNode (void) const =0
virtual unsigned int GetNumberOfIntegrationPoints (unsigned int order) const
virtual unsigned int GetNumberOfNodes (void) const
virtual unsigned int GetNumberOfSpatialDimensions () const
virtual void GetStiffnessMatrix (MatrixType &Ke) const
virtual void GetStrainDisplacementMatrix (MatrixType &B, const MatrixType &shapeDgl) const =0
virtual VectorType GetStrainsAtPoint (const VectorType &pt, const Solution &sol, unsigned int index) const
virtual VectorType GetStressesAtPoint (const VectorType &pt, const VectorType &e, const Solution &sol, unsigned int index) const
virtual VectorType InterpolateSolution (const VectorType &pt, const Solution &sol, unsigned int solutionIndex=0) const
virtual Float InterpolateSolutionN (const VectorType &pt, const Solution &sol, unsigned int f, unsigned int solutionIndex=0) const
virtual void Jacobian (const VectorType &pt, MatrixType &J, const MatrixType *pshapeD=0) const
virtual Float JacobianDeterminant (const VectorType &pt, const MatrixType *pJ=0) const
virtual void JacobianInverse (const VectorType &pt, MatrixType &invJ, const MatrixType *pJ=0) const
virtual void Read (std::istream &, void *info)
virtual void SetMaterial (Material::ConstPointer)
virtual void SetNode (unsigned int n, NodeIDType node)
virtual void ShapeFunctionDerivatives (const VectorType &pt, MatrixType &shapeD) const
virtual void ShapeFunctionGlobalDerivatives (const VectorType &pt, MatrixType &shapeDgl, const MatrixType *pJ=0, const MatrixType *pshapeD=0) const
virtual VectorType ShapeFunctions (const VectorType &pt) const
virtual void Write (std::ostream &f) const
DegreeOfFreedomIDType GetDegreeOfFreedom (unsigned int local_dof) const

Static Public Member Functions

static FEMLightObject::Pointer CreateFromStream (std::istream &f, void *info)
static void SkipWhiteSpace (std::istream &f)

Public Attributes

int GN

Static Public Attributes

static const Float gaussPoint [gaussMaxOrder+1][gaussMaxOrder]
static const Float gaussWeight [gaussMaxOrder+1][gaussMaxOrder]
static const std::string whitespaces

Protected Attributes

NodeIDType m_node [NumberOfNodes]


Detailed Description

8-noded, linear, C0 continuous finite element in 3D space.

Definition at line 30 of file itkFEMElement3DC0LinearHexahedron.h.


Member Typedef Documentation

Array class that holds special pointers to the Element objects

Definition at line 88 of file itkFEMElementBase.h.

Store the base class typedef for easy access from derived classes. FEM_CLASS macro also expects this for the FEMOF...

Definition at line 64 of file itkFEMLightObject.h.

typedef Superclass::DegreeOfFreedomIDType itk::fem::ElementStd< VNumberOfNodes, VNumberOfSpatialDimensions, Element >::DegreeOfFreedomIDType [inherited]

Reimplemented from itk::fem::Element.

Definition at line 67 of file itkFEMElementStd.h.

typedef Superclass::Float itk::fem::ElementStd< VNumberOfNodes, VNumberOfSpatialDimensions, Element >::Float [inherited]

typedef Superclass::LoadPointer itk::fem::ElementStd< VNumberOfNodes, VNumberOfSpatialDimensions, Element >::LoadPointer [inherited]

Reimplemented from itk::fem::Element.

Definition at line 65 of file itkFEMElementStd.h.

typedef Superclass::LoadType itk::fem::ElementStd< VNumberOfNodes, VNumberOfSpatialDimensions, Element >::LoadType [inherited]

Reimplemented from itk::fem::Element.

Definition at line 64 of file itkFEMElementStd.h.

typedef Superclass::MatrixType itk::fem::ElementStd< VNumberOfNodes, VNumberOfSpatialDimensions, Element >::MatrixType [inherited]

typedef Superclass::Node itk::fem::ElementStd< VNumberOfNodes, VNumberOfSpatialDimensions, Element >::Node [inherited]

Definition at line 68 of file itkFEMElementStd.h.

typedef Superclass::NodeIDType itk::fem::ElementStd< VNumberOfNodes, VNumberOfSpatialDimensions, Element >::NodeIDType [inherited]

Reimplemented from itk::fem::Element.

Definition at line 66 of file itkFEMElementStd.h.

typedef Superclass::VectorType itk::fem::ElementStd< VNumberOfNodes, VNumberOfSpatialDimensions, Element >::VectorType [inherited]


Member Enumeration Documentation

anonymous enum [inherited]

Constant that represents an invalid DegreeOfFreedomID object. If a degree of freedom is assigned this value, this means that that no specific value was (yet) assigned to this DOF.

Enumerator:
InvalidDegreeOfFreedomID 

Definition at line 125 of file itkFEMElementBase.h.

anonymous enum [inherited]

Maximum supported order of 1D Gauss-Legendre integration. Integration points are defined for orders from 1 to gaussMaxOrder. Number of integration points is equal to the order of integration rule.

See also:
gaussPoint
Enumerator:
gaussMaxOrder 

Definition at line 473 of file itkFEMElementBase.h.

anonymous enum [inherited]

Definition at line 69 of file itkFEMElementStd.h.

anonymous enum [inherited]

Number of nodes that define the element.

Definition at line 74 of file itkFEMElementStd.h.

anonymous enum [inherited]

Number of dimensions of space in which element can exist.

Definition at line 79 of file itkFEMElementStd.h.


Member Function Documentation

virtual int itk::fem::FEMLightObject::ClassID (  )  const [pure virtual, inherited]

virtual Baseclass::Pointer itk::fem::FEMLightObject::Clone (  )  const [pure virtual, inherited]

static FEMLightObject::Pointer itk::fem::FEMLightObject::CreateFromStream ( std::istream &  f,
void *  info 
) [static, inherited]

Read object of any derived type from stream.

This static function creates an object of a class, which is derived from FEMLightObject. The class of object is first determined from the stream, then the object of that class is constructed using the FEMObjectFactory. Finally the data for this object is read from the stream, by calling the Read() member function.

DegreeOfFreedomIDType itk::fem::Element::GetDegreeOfFreedom ( unsigned int  local_dof  )  const [inline, inherited]

Convenient way to access IDs of degrees of freedom that are stored in node objects.

Parameters:
local_dof Local number of degree of freedom within an element.

Definition at line 389 of file itkFEMElementBase.h.

References itk::fem::Element::Element::Node::GetDegreeOfFreedom(), itk::fem::Element::GetNode(), itk::fem::Element::GetNumberOfDegreesOfFreedom(), itk::fem::Element::GetNumberOfDegreesOfFreedomPerNode(), and itk::fem::Element::InvalidDegreeOfFreedomID.

virtual Float itk::fem::Element::GetElementDeformationEnergy ( MatrixType LocalSolution  )  const [virtual, inherited]

Compute the physical energy, U, of the deformation (e.g. stress / strain ).

T U = u Ke u

The matrix LocalSolution contains the solution to use in the energy computation. Usually, this is the solution at the nodes.

virtual VectorType itk::fem::Element::GetGlobalFromLocalCoordinates ( const VectorType pt  )  const [virtual, inherited]

Transforms the given local element coordinates into global.

Parameters:
pt Point in local element coordinates.

virtual void itk::fem::Element3DC0LinearHexahedron::GetIntegrationPointAndWeight ( unsigned int  i,
VectorType pt,
Float w,
unsigned int  order 
) const [virtual]

Methods related to numeric integration

Implements itk::fem::Element.

virtual void itk::fem::Element::GetLandmarkContributionMatrix ( float  eta,
MatrixType Le 
) const [virtual, inherited]

Compute and return landmark contribution to element stiffness matrix (Le) in global coordinate system.

b T int (1/eta)^2 N(x) N(x) dx a

where (eta ) is the landmark weight. Implementation is similar to GetMassMatrix.

virtual void itk::fem::Element::GetLoadVector ( LoadPointer  l,
VectorType Fe 
) const [pure virtual, inherited]

Compute and return the element load vector for a given external load. The class of load object determines the type of load acting on the elemnent. Basically this is the contribution of this element on the right side of the master matrix equation, due to the specified load. Returned vector includes only nodal forces that correspond to the given Load object.

Visitor design pattern is used in the loads implementation. This function only selects and calls the proper function based on the given class of load object. The code that performs the actual conversion to the corresponding nodal loads is defined elswhere.

Note:
Each derived class must implement its own version of this function. This is automated by calling the LOAD_FUNCTION() macro within the class declaration (in the public: block).
For example on how to define specific element load, see funtion LoadImplementationPoint_Bar2D.

Note:
: Before a load can be applied to an element, the function that implements a load must be registered with the VisitorDispactcher class.
Parameters:
l Pointer to a load object.
Fe Reference to vector object that will store nodal forces.
See also:
VisitorDispatcher

virtual bool itk::fem::Element3DC0LinearHexahedron::GetLocalFromGlobalCoordinates ( const VectorType globalPt,
VectorType localPt 
) const [virtual]

Transforms the given global element coordinates into local. Returns false if the point is outside.

Parameters:
globalPt Reference to vector containing a point in global (world) coordinates.
localPt Reference to the vector that will store the local coordinate.

Implements itk::fem::Element.

virtual void itk::fem::Element::GetMassMatrix ( MatrixType Me  )  const [virtual, inherited]

virtual Material::ConstPointer itk::fem::Element::GetMaterial ( void   )  const [inline, virtual, inherited]

Return the pointer to the Material object used by the element. All derived classes, which use objects of Material class should override this method to provide access to the material from the base class.

Note:
Derived Element classes don't have to use a material class, but since the majority of the final Element classes uses Material classes to specify phhysical constants that the element depends on, we provide this virtual function that enables easy access to this pointer from the base class. If the derived class does not override this function, the returned pointer is 0 by default, signaling that there is no Material object.
See also:
SetMaterial

Reimplemented in itk::fem::Element2DC1Beam, itk::fem::Element1DStress< Element2DC0LinearLine >, itk::fem::Element2DMembrane< Element2DC0LinearTriangular >, itk::fem::Element2DMembrane< Element2DC0LinearQuadrilateral >, itk::fem::Element2DStrain< Element2DC0LinearTriangular >, itk::fem::Element2DStrain< Element2DC0QuadraticTriangular >, itk::fem::Element2DStrain< Element2DC0LinearQuadrilateral >, itk::fem::Element2DStress< Element2DC0LinearTriangular >, itk::fem::Element2DStress< Element2DC0QuadraticTriangular >, itk::fem::Element2DStress< Element2DC0LinearQuadrilateral >, itk::fem::Element3DMembrane< Element3DC0LinearTetrahedron >, itk::fem::Element3DMembrane< Element3DC0LinearHexahedron >, itk::fem::Element3DStrain< Element3DC0LinearTetrahedron >, and itk::fem::Element3DStrain< Element3DC0LinearHexahedron >.

Definition at line 412 of file itkFEMElementBase.h.

virtual void itk::fem::Element::GetMaterialMatrix ( MatrixType D  )  const [pure virtual, inherited]

virtual NodeIDType itk::fem::ElementStd< VNumberOfNodes, VNumberOfSpatialDimensions, Element >::GetNode ( unsigned int  n  )  const [inline, virtual, inherited]

Implements itk::fem::Element.

Definition at line 93 of file itkFEMElementStd.h.

virtual const VectorType& itk::fem::ElementStd< VNumberOfNodes, VNumberOfSpatialDimensions, Element >::GetNodeCoordinates ( unsigned int  n  )  const [inline, virtual, inherited]

Implements itk::fem::Element.

Definition at line 111 of file itkFEMElementStd.h.

virtual unsigned int itk::fem::Element::GetNumberOfDegreesOfFreedom ( void   )  const [inline, virtual, inherited]

Return the total number of degrees of freedom defined in a derived element class. By default this is equal to number of points in a cell multiplied by number of degrees of freedom at each point.

Definition at line 650 of file itkFEMElementBase.h.

References itk::fem::Element::GetNumberOfDegreesOfFreedomPerNode(), and itk::fem::Element::GetNumberOfNodes().

Referenced by itk::fem::Element::GetDegreeOfFreedom().

virtual unsigned int itk::fem::Element::GetNumberOfDegreesOfFreedomPerNode ( void   )  const [pure virtual, inherited]

virtual unsigned int itk::fem::Element3DC0LinearHexahedron::GetNumberOfIntegrationPoints ( unsigned int  order  )  const [virtual]

Returns total number of integration points, for given order of Gauss-Legendre numerical integration rule.

Note:
This function must be implemented in derived element classes, and is expected to provide valid number of integration points for up to gaussMaxOrder-th order of integration.
See also:
GetIntegrationPointAndWeight()

Implements itk::fem::Element.

virtual unsigned int itk::fem::ElementStd< VNumberOfNodes, VNumberOfSpatialDimensions, Element >::GetNumberOfNodes ( void   )  const [inline, virtual, inherited]

Methods that define the geometry of an element

Implements itk::fem::Element.

Definition at line 90 of file itkFEMElementStd.h.

virtual unsigned int itk::fem::ElementStd< VNumberOfNodes, VNumberOfSpatialDimensions, Element >::GetNumberOfSpatialDimensions (  )  const [inline, virtual, inherited]

Implements itk::fem::Element.

Definition at line 116 of file itkFEMElementStd.h.

virtual void itk::fem::Element::GetStiffnessMatrix ( MatrixType Ke  )  const [virtual, inherited]

Compute and return element stiffnes matrix (Ke) in global coordinate system. The base class provides a general implementation which only computes

b T int B(x) D B(x) dx a

using the Gaussian numeric integration method. The function calls GetIntegrationPointAndWeight() / GetNumberOfIntegrationPoints() to obtain the integration points. It also calls the GetStrainDisplacementMatrix() and GetMaterialMatrix() member functions.

Parameters:
Ke Reference to the resulting stiffnes matrix.
Note:
This is a very generic implementation of the stiffness matrix that is suitable for any problem/element definition. A specifc element may override this implementation with its own simple one.

Reimplemented in itk::fem::Element2DC1Beam, and itk::fem::Element1DStress< Element2DC0LinearLine >.

virtual void itk::fem::Element::GetStrainDisplacementMatrix ( MatrixType B,
const MatrixType shapeDgl 
) const [pure virtual, inherited]

virtual VectorType itk::fem::Element::GetStrainsAtPoint ( const VectorType pt,
const Solution sol,
unsigned int  index 
) const [virtual, inherited]

virtual VectorType itk::fem::Element::GetStressesAtPoint ( const VectorType pt,
const VectorType e,
const Solution sol,
unsigned int  index 
) const [virtual, inherited]

virtual VectorType itk::fem::Element::InterpolateSolution ( const VectorType pt,
const Solution sol,
unsigned int  solutionIndex = 0 
) const [virtual, inherited]

Return interpolated value of all unknown functions at given local point.

Parameters:
pt Point in local element coordinates.
sol Reference to the master solution object. This object is created by the Solver object when the whole FEM problem is solved and contains the values of unknown functions at nodes (degrees of freedom).
solutionIndex We allow more than one solution vector to be stored - this selects which to use in interpolation.

virtual Float itk::fem::Element::InterpolateSolutionN ( const VectorType pt,
const Solution sol,
unsigned int  f,
unsigned int  solutionIndex = 0 
) const [virtual, inherited]

Return interpolated value of f-th unknown function at given local point.

Parameters:
pt Point in local element coordinates.
sol Reference to the master solution object. This object is created by the Solver object when the whole FEM problem is solved and contains the values of unknown functions at nodes (degrees of freedom).
f Number of unknown function to interpolate. Must be 0 <= f < GetNumberOfDegreesOfFreedomPerNode().
solutionIndex We allow more than one solution vector to be stored - this selects which to use in interpolation.

virtual void itk::fem::Element::Jacobian ( const VectorType pt,
MatrixType J,
const MatrixType pshapeD = 0 
) const [virtual, inherited]

Compute the Jacobian matrix of the transformation from local to global coordinates at a given local point.

A column in this matrix corresponds to a global coordinate, while a row corresponds to different local coordinates. E.g. element at row 2, col 3 contains derivative of the third global coordinate with respect to local coordinate number 2.

In order to compute the Jacobian, we normally need the shape function derivatives. If they are known, you should pass a pointer to an object of MatrixType that contains the shape function derivatives. If they are not known, pass null pointer and they will be computed automatically.

Parameters:
pt Point in local coordinates
J referece to matrix object, which will contain the jacobian
pshapeD A pointer to derivatives of shape functions at point pt. If this pointer is 0, derivatives will be computed as necessary.

Reimplemented in itk::fem::Element2DC0LinearLine.

virtual Float itk::fem::Element::JacobianDeterminant ( const VectorType pt,
const MatrixType pJ = 0 
) const [virtual, inherited]

Compute the determinant of the Jacobian matrix at a given point with respect to the local coordinate system.

Parameters:
pt Point in local element coordinates.
pJ Optional pointer to Jacobian matrix computed at point pt. If this is set to 0, the Jacobian will be computed as necessary.

Reimplemented in itk::fem::Element2DC0LinearTriangular, itk::fem::Element2DC0QuadraticTriangular, and itk::fem::Element2DC1Beam.

virtual void itk::fem::Element::JacobianInverse ( const VectorType pt,
MatrixType invJ,
const MatrixType pJ = 0 
) const [virtual, inherited]

Compute the inverse of the Jacobian matrix at a given point with respect to the local coordinate system.

Parameters:
pt Point in local element coordinates.
invJ Reference to the object of MatrixType that will store the computed inverse if Jacobian.
pJ Optional pointer to Jacobian matrix computed at point pt. If this is set to 0, the Jacobian will be computed as necessary.

Reimplemented in itk::fem::Element2DC0LinearTriangular, and itk::fem::Element2DC0QuadraticTriangular.

virtual void itk::fem::ElementStd< VNumberOfNodes, VNumberOfSpatialDimensions, Element >::Read ( std::istream &  ,
void *  info 
) [virtual, inherited]

Methods related to I/O Read data for this class from input stream

Reimplemented from itk::fem::FEMLightObject.

Reimplemented in itk::fem::Element3DMembrane< Element3DC0LinearHexahedron >, and itk::fem::Element3DStrain< Element3DC0LinearHexahedron >.

virtual void itk::fem::Element::SetMaterial ( Material::ConstPointer   )  [inline, virtual, inherited]

virtual void itk::fem::ElementStd< VNumberOfNodes, VNumberOfSpatialDimensions, Element >::SetNode ( unsigned int  n,
NodeIDType  node 
) [inline, virtual, inherited]

Implements itk::fem::Element.

Definition at line 102 of file itkFEMElementStd.h.

virtual void itk::fem::Element3DC0LinearHexahedron::ShapeFunctionDerivatives ( const VectorType pt,
MatrixType shapeD 
) const [virtual]

Compute the matrix of values of the shape functions derivatives with respect to local coordinates of this element at a given point.

A column in this matrix corresponds to a specific shape function, while a row corresponds to different local coordinates. E.g. element at row 2, col 3 contains derivative of shape function number 3 with respect to local coordinate number 2.

Parameters:
pt Point in local element coordinates.
shapeD Reference to a matrix object, which will be filled with values of shape function derivatives.
See also:
ShapeFunctionGlobalDerivatives

Implements itk::fem::Element.

virtual void itk::fem::Element::ShapeFunctionGlobalDerivatives ( const VectorType pt,
MatrixType shapeDgl,
const MatrixType pJ = 0,
const MatrixType pshapeD = 0 
) const [virtual, inherited]

Compute matrix of shape function derivatives with respect to global coordinates.

A column in this matrix corresponds to a specific shape function, while a row corresponds to different global coordinates.

Parameters:
pt Point in local element coordinates.
shapeDgl Reference to a matrix object, which will be filled with values of shape function derivatives w.r.t. global (world) element coordinates.
pJ Optional pointer to Jacobian matrix computed at point pt. If this is set to 0, the Jacobian will be computed as necessary.
pshapeD A pointer to derivatives of shape functions at point pt. If this pointer is 0, derivatives will be computed as necessary.
See also:
ShapeFunctionDerivatives

virtual VectorType itk::fem::Element3DC0LinearHexahedron::ShapeFunctions ( const VectorType pt  )  const [virtual]

Methods related to the geometry of an element

Implements itk::fem::Element.

static void itk::fem::FEMLightObject::SkipWhiteSpace ( std::istream &  f  )  [static, inherited]

Helper function that skips all the whitespace and comments in an input stream.

virtual void itk::fem::ElementStd< VNumberOfNodes, VNumberOfSpatialDimensions, Element >::Write ( std::ostream &  f  )  const [virtual, inherited]


Member Data Documentation

const Float itk::fem::Element::gaussPoint[gaussMaxOrder+1][gaussMaxOrder] [static, inherited]

Points for 1D Gauss-Legendre integration from -1 to 1. First index is order of integration, second index is the number of integration point.

Example: gaussPoint[4][2] returns third point of the 4th order integration rule. Subarray gaussPoint[0][...] does not provide useful information. It is there only to keep order index correct.

See also:
gaussWeight

Definition at line 486 of file itkFEMElementBase.h.

const Float itk::fem::Element::gaussWeight[gaussMaxOrder+1][gaussMaxOrder] [static, inherited]

Weights for Gauss-Legendre integration.

See also:
gaussPoint

Definition at line 493 of file itkFEMElementBase.h.

Global number of an object (ID of an object) In general the ID's are required to be unique only within a specific type of derived classes (Elements, Nodes, ...) If the GN is not required, it can be ignored. (normally you need the GN when writing or reading objects to/from stream.

Definition at line 165 of file itkFEMLightObject.h.

Referenced by itk::fem::FEMLightObject::FEMLightObject().

NodeIDType itk::fem::ElementStd< VNumberOfNodes, VNumberOfSpatialDimensions, Element >::m_node[NumberOfNodes] [protected, inherited]

Array of pointers to point objects that define the element

Definition at line 141 of file itkFEMElementStd.h.

const std::string itk::fem::FEMLightObject::whitespaces [static, inherited]

Const string of all whitespace characters. This string is used by SkipWhiteSpace function.

Definition at line 135 of file itkFEMLightObject.h.


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

Generated at Tue Sep 15 15:09:21 2009 for ITK by doxygen 1.5.8 written by Dimitri van Heesch, © 1997-2000