UWLigamentMaterial (Artisynth API documentation)

java.lang.Object
- artisynth.core.materials.MaterialBase
- - artisynth.core.materials.AxialMaterial
  - - artisynth.core.materials.UWLigamentMaterial

All Implemented Interfaces:

HasMaterialState, PostScannable, ScalableUnits, java.lang.Cloneable, CompositeProperty, HasProperties, Clonable, Scannable
```
public class UWLigamentMaterial
extends AxialMaterial
```
The ligament model used in the University of Wisconsin knee model. Based on: Blankevoort, L., and Huiskes, R. (1991). Ligament-bone interaction in a three-dimensional model of the knee. Journal of Biomechanical Engineering, 113(3), 263-269. implementation adapted from UW SimTk plugin: https://simtk.org/home/uwmodels Notes: - the restLength property in the associated spring is used as the referenceLength in the UW formulation, where referenceLength is the length of the ligament when the joint is in the reference position (full extension).

Field Summary

Fields
Modifier and Type	Field and Description
`static double`	`DEFAULT_LIGAMENT_TRANSITION_STRAIN`
`static double`	`DEFAULT_LINEAR_STIFFNESS`
`static double`	`DEFAULT_MAX_FORCE`
`static double`	`DEFAULT_NORMALIZED_DAMPING`
`static double`	`DEFAULT_REFERENCE_STRAIN`
`static double`	`DEFAULT_TENDON_SLACK_LENGTH`
`static PropertyList`	`myProps`

Constructor Summary

Constructors
Constructor and Description

UWLigamentMaterial()

Constructors
Constructor and Description
`UWLigamentMaterial()`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`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`	`getLigamentTransitionStrain()`
`double`	`getLinearStiffness()`
`double`	`getMaxForce()`
`double`	`getNormalizedDamping()`
`double`	`getReferenceStrain()`
`double`	`getTendonSlackLength()`
`boolean`	`isDFdldotZero()` Returns true if computeDFdldot() always returns zero.
`void`	`setLigamentTransitionStrain(double ligamentTransitionStrain)`
`void`	`setLinearStiffness(double linearStiffness)`
`void`	`setMaxForce(double maxForce)`
`void`	`setNormalizedDamping(double normalizedDamping)`
`void`	`setReferenceStrain(double referenceStrain)`
`void`	`setTendonSlackLength(double tendonSlackLength)`

Methods inherited from class artisynth.core.materials.AxialMaterial
clone, 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, writeItems

Methods inherited from class java.lang.Object
getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - DEFAULT_REFERENCE_STRAIN
```
public static double DEFAULT_REFERENCE_STRAIN
```
  - DEFAULT_LINEAR_STIFFNESS
```
public static double DEFAULT_LINEAR_STIFFNESS
```
  - DEFAULT_LIGAMENT_TRANSITION_STRAIN
```
public static double DEFAULT_LIGAMENT_TRANSITION_STRAIN
```
  - DEFAULT_NORMALIZED_DAMPING
```
public static double DEFAULT_NORMALIZED_DAMPING
```
  - DEFAULT_MAX_FORCE
```
public static double DEFAULT_MAX_FORCE
```
  - DEFAULT_TENDON_SLACK_LENGTH
```
public static double DEFAULT_TENDON_SLACK_LENGTH
```
  - myProps
```
public static PropertyList myProps
```
- Constructor Detail
  - UWLigamentMaterial
```
public UWLigamentMaterial()
```
- 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
  - computeF
```
public double computeF(double l,
                       double ldot,
                       double l0,
                       double excitation)
```
    Description copied from class: AxialMaterial
    
    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)
```
    Description copied from class: AxialMaterial
    
    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)
```
    Description copied from class: AxialMaterial
    
    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()
```
    Description copied from class: AxialMaterial
    
    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
  - getReferenceStrain
```
public double getReferenceStrain()
```
  - setReferenceStrain
```
public void setReferenceStrain(double referenceStrain)
```
  - getLinearStiffness
```
public double getLinearStiffness()
```
  - setLinearStiffness
```
public void setLinearStiffness(double linearStiffness)
```
  - getLigamentTransitionStrain
```
public double getLigamentTransitionStrain()
```
  - setLigamentTransitionStrain
```
public void setLigamentTransitionStrain(double ligamentTransitionStrain)
```
  - getNormalizedDamping
```
public double getNormalizedDamping()
```
  - setNormalizedDamping
```
public void setNormalizedDamping(double normalizedDamping)
```
  - getMaxForce
```
public double getMaxForce()
```
  - setMaxForce
```
public void setMaxForce(double maxForce)
```
  - getTendonSlackLength
```
public double getTendonSlackLength()
```
  - setTendonSlackLength
```
public void setTendonSlackLength(double tendonSlackLength)
```

Class UWLigamentMaterial

Field Summary

Constructor Summary

Method Summary

Methods inherited from class artisynth.core.materials.AxialMaterial

Methods inherited from class artisynth.core.materials.MaterialBase

Methods inherited from class java.lang.Object

Field Detail

DEFAULT_REFERENCE_STRAIN

DEFAULT_LINEAR_STIFFNESS

DEFAULT_LIGAMENT_TRANSITION_STRAIN

DEFAULT_NORMALIZED_DAMPING

DEFAULT_MAX_FORCE

DEFAULT_TENDON_SLACK_LENGTH

myProps

Constructor Detail

UWLigamentMaterial

Method Detail

getAllPropertyInfo

computeF

computeDFdl

computeDFdldot

isDFdldotZero

getReferenceStrain

setReferenceStrain

getLinearStiffness

setLinearStiffness

getLigamentTransitionStrain

setLigamentTransitionStrain

getNormalizedDamping

setNormalizedDamping

getMaxForce

setMaxForce

getTendonSlackLength

setTendonSlackLength