artisynth.core.femmodels

Class StiffnessWarper3d

java.lang.Object

artisynth.core.femmodels.StiffnessWarper3d

public class StiffnessWarper3d
extends java.lang.Object

Implements stiffness warping for a particular 3D FEM element.

Note: it is important that all these methods are called from the same (simulation) thread. In particular, they should not be called by methods activated by the GUI.

Constructor Summary

Constructors

Constructor and Description
StiffnessWarper3d(FemElement3dBase elem)

Method Summary

Modifier and Type	Method and Description
void	addInitialStiffness(FemElement3dBase e, AuxiliaryMaterial mat, double weight) Adds linear stiffness contributions to an underlying cache
void	addInitialStiffness(FemElement3dBase e, FemMaterial mat, double weight) Adds linear stiffness contributions to an underlying cache
void	addNodeForce(Vector3d f, int i, FemNode3d[] nodes) Adds the total force contribution due to stiffness from all cached linear materials for node i
void	addNodeForce(Vector3d f, Vector3d fback, int i, FemNode3d[] nodes)
void	addNodeForce0(VectorNd f, int offset, int i) Adds initial force contribution due to cached stiffness
void	addNodeStiffness(FemNodeNeighbor nbr, int i, int j)
void	addNodeStiffness(Matrix3d K, int i, int j) Adds the total stiffness contributions between nodes i and j from all cached linear and corotated linear materials to the given matrix
static void	computeRotation(RotationMatrix3d R, SymmetricMatrix3d P, Matrix3d F) Computes a corotated rotation based on the deformation gradient
void	computeWarpingRotation(FemElement3dBase elem)
RotationMatrix3d	getRotation() Gets current warping rotation matrix
void	initialize(FemElement3dBase elem) Initializes the warper, clears any cached values
boolean	isCacheEmpty() Checks if warper contains any cached data
void	setRotation(Matrix3dBase R) Manually sets rotation to use for warping

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

StiffnessWarper3d

public StiffnessWarper3d(FemElement3dBase elem)

Method Detail

initialize

public void initialize(FemElement3dBase elem)

Initializes the warper, clears any cached values

Parameters:

elem - element to be used by warper

isCacheEmpty

public boolean isCacheEmpty()

Checks if warper contains any cached data

Returns:

true if contains cached data, false otherwise

addInitialStiffness

public void addInitialStiffness(FemElement3dBase e,
                                FemMaterial mat,
                                double weight)

Adds linear stiffness contributions to an underlying cache

Parameters:

e - FEM element

mat - linear material

weight - weight to combine with integration point weights

addInitialStiffness

public void addInitialStiffness(FemElement3dBase e,
                                AuxiliaryMaterial mat,
                                double weight)

Adds linear stiffness contributions to an underlying cache

Parameters:

e - FEM element

mat - linear material

weight - weight to combine with integration point weights

computeWarpingRotation

public void computeWarpingRotation(FemElement3dBase elem)

computeRotation

public static void computeRotation(RotationMatrix3d R,
                                   SymmetricMatrix3d P,
                                   Matrix3d F)

Computes a corotated rotation based on the deformation gradient

Parameters:

R - returns the rotation

F - deformation gradient

P - symmetric part of gradient after rotation

setRotation

public void setRotation(Matrix3dBase R)

Manually sets rotation to use for warping

Parameters:

R - warping rotation

getRotation

public RotationMatrix3d getRotation()

Gets current warping rotation matrix

Returns:

warping rotation

addNodeStiffness

public void addNodeStiffness(Matrix3d K,
                             int i,
                             int j)

Adds the total stiffness contributions between nodes i and j from all cached linear and corotated linear materials to the given matrix

Parameters:

K - local stiffness matrix

i - first node index

j - second node index

addNodeStiffness

public void addNodeStiffness(FemNodeNeighbor nbr,
                             int i,
                             int j)

addNodeForce

public void addNodeForce(Vector3d f,
                         int i,
                         FemNode3d[] nodes)

Adds the total force contribution due to stiffness from all cached linear materials for node i

Parameters:

f - output force

i - node index

nodes - element nodes

addNodeForce

public void addNodeForce(Vector3d f,
                         Vector3d fback,
                         int i,
                         FemNode3d[] nodes)

addNodeForce0

public void addNodeForce0(VectorNd f,
                          int offset,
                          int i)

Adds initial force contribution due to cached stiffness

Parameters:

f - output force vector

offset - offset within force vector to add contribution

i - node for which to add force