artisynth.core.materials

Class AxialTendonBase

java.lang.Object

artisynth.core.materials.MaterialBase

artisynth.core.materials.AxialMaterial

artisynth.core.materials.AxialTendonBase

All Implemented Interfaces:

HasMaterialState, PostScannable, ScalableUnits, java.lang.Cloneable, CompositeProperty, HasProperties, Clonable, Scannable

Direct Known Subclasses:

Millard2012AxialTendon, Thelen2003AxialTendon

public abstract class AxialTendonBase
extends AxialMaterial

Base class for point-to-point muscle materials that implement muscle tendons.

Field Summary

Fields

Modifier and Type	Field and Description
static double	DEFAULT_FMAX_TENDON_STRAIN
static double	DEFAULT_MAX_ISO_FORCE
static double	DEFAULT_TENDON_SLACK_LENGTH
static PropertyList	myProps

Constructor Summary

Constructors

Constructor and Description
AxialTendonBase()

Method Summary

Modifier and Type	Method and Description
AxialTendonBase	clone() Returns a clone of this composite property.
double	computeDFdl(double l, double ldot, double l0, double excitation) Computes and returns the derivative of the axial spring tension with respect to the length.
double	computeDFdldot(double l, double ldot, double l0, double excitation) Computes and returns the derivative of the axial spring tension with respect to the length time derivative.
double	computeF(double l, double ldot, double l0, double excitation) Computes and returns the axial spring tension, as a function of length, length time derivative, rest length, and excitation.
PropertyList	getAllPropertyInfo() Returns a list giving static information about all properties exported by this object.
double	getMaxIsoForce()
CubicHermiteSpline1d	getTendonForceLengthCurve() Queries the tendon force length curve for this material.
double	getTendonSlackLength()
boolean	isDFdldotZero() Returns true if computeDFdldot() always returns zero.
void	setMaxIsoForce(double fmax)
void	setTendonForceLengthCurve(CubicHermiteSpline1d curve) Sets the tendon force length curve for this material, or removes it if curve is set to null.
void	setTendonSlackLength(double l)
void	writeItems(java.io.PrintWriter pw, NumberFormat fmt, CompositeComponent ancestor)

Methods inherited from class artisynth.core.materials.AxialMaterial

equals, equals, getSubClasses

Methods inherited from class artisynth.core.materials.MaterialBase

advanceState, createStateObject, getProperty, getPropertyHost, getPropertyInfo, hasProperty, hasState, hasSymmetricTangent, isWritable, postscan, scaleDistance, scaleMass, scan, setPropertyHost, setPropertyInfo, symmetryOrStateChanged, updateMaterial, write

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_MAX_ISO_FORCE

public static double DEFAULT_MAX_ISO_FORCE

DEFAULT_TENDON_SLACK_LENGTH

public static double DEFAULT_TENDON_SLACK_LENGTH

DEFAULT_FMAX_TENDON_STRAIN

public static double DEFAULT_FMAX_TENDON_STRAIN

myProps

public static PropertyList myProps

Constructor Detail

AxialTendonBase

public AxialTendonBase()

Method Detail

getAllPropertyInfo

public PropertyList getAllPropertyInfo()

Description copied from interface: HasProperties

Returns a list giving static information about all properties exported by this object.

Specified by:

getAllPropertyInfo in interface HasProperties

Overrides:

getAllPropertyInfo in class MaterialBase

Returns:

static information for all exported properties

getMaxIsoForce

public double getMaxIsoForce()

setMaxIsoForce

public void setMaxIsoForce(double fmax)

getTendonSlackLength

public double getTendonSlackLength()

setTendonSlackLength

public void setTendonSlackLength(double l)

getTendonForceLengthCurve

public CubicHermiteSpline1d getTendonForceLengthCurve()

Queries the tendon force length curve for this material. Returns null if this curve has not been set.

Returns:

current tendon force length curve

setTendonForceLengthCurve

public void setTendonForceLengthCurve(CubicHermiteSpline1d curve)

Sets the tendon force length curve for this material, or removes it if curve is set to null. Any specified curve is copied internally.

Parameters:

curve - new tendon force length curve

computeF

public double computeF(double l,
                       double ldot,
                       double l0,
                       double excitation)

Computes and returns the axial spring tension, as a function of length, length time derivative, rest length, and excitation.

Specified by:

computeF in class AxialMaterial

Parameters:

l - spring length

ldot - spring length time derivative

l0 - spring rest length

excitation - excitation value (varying from 0 to 1)

Returns:

spring tension

computeDFdl

public double computeDFdl(double l,
                          double ldot,
                          double l0,
                          double excitation)

Computes and returns the derivative of the axial spring tension with respect to the length.

Specified by:

computeDFdl in class AxialMaterial

Parameters:

l - spring length

ldot - spring length time derivative

l0 - spring rest length

excitation - excitation value (varying from 0 to 1)

Returns:

tension derivative with respect to length

computeDFdldot

public double computeDFdldot(double l,
                             double ldot,
                             double l0,
                             double excitation)

Computes and returns the derivative of the axial spring tension with respect to the length time derivative.

Specified by:

computeDFdldot in class AxialMaterial

Parameters:

l - spring length

ldot - spring length time derivative

l0 - spring rest length

excitation - excitation value (varying from 0 to 1)

Returns:

tension derivative with respect to length time derivative

isDFdldotZero

public boolean isDFdldotZero()

Returns true if computeDFdldot() always returns zero. For a linear spring, this simply means the damping is zero. When dFdldot is always 0, then stiffness matrix will be symmetric.

Specified by:

isDFdldotZero in class AxialMaterial

writeItems

public void writeItems(java.io.PrintWriter pw,
                       NumberFormat fmt,
                       CompositeComponent ancestor)
                throws java.io.IOException

Overrides:

writeItems in class MaterialBase

Throws:

java.io.IOException

clone

public AxialTendonBase clone()

Description copied from interface: CompositeProperty

Returns a clone of this composite property.

Specified by:

clone in interface CompositeProperty

Specified by:

clone in interface Clonable

Overrides:

clone in class AxialMaterial

Returns:

clone of this property