artisynth.core.materials

Class ElasticContactBase

java.lang.Object

artisynth.core.materials.MaterialBase

artisynth.core.materials.ContactForceBehavior

artisynth.core.materials.ElasticContactBase

All Implemented Interfaces:

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

Direct Known Subclasses:

LinearElasticContact

public abstract class ElasticContactBase
extends ContactForceBehavior

Base class for elastic foundation contact implementations.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ElasticContactBase.DampingMethod Describes how the method computeDamping(double, double) computes the net damping d from the damping factor df.

Field Summary

Fields

Modifier and Type	Field and Description
static FieldPropertyList	myProps

Fields inherited from class artisynth.core.materials.ContactForceBehavior

TWO_WAY_CONTACT

Constructor Summary

Constructors

Constructor and Description
ElasticContactBase() Need no-args constructor for scanning

Method Summary

Modifier and Type	Method and Description
ElasticContactBase	clone() Returns a clone of this composite property.
FieldPropertyList	getAllPropertyInfo() Returns a list giving static information about all properties exported by this object.
double	getDampingFactor() Queries the damping factor for this material.
ElasticContactBase.DampingMethod	getDampingMethod() Queries the damping method for this material.
double	getMinThicknessRatio() Queries the minimum thickness ratio for this material.
double	getThickness() Queries the thickness of the foundation layer.
ScalarFieldComponent	getThicknessField() Queries the field, if any, associated with the foundation thickness.
boolean	getUseLocalContactArea() Queries whether local contact areas are used for computing contact pressure.
boolean	getUseLogDistance() Queries whether log distances are used for computing contact forces.
void	setDampingFactor(double df) Sets the damping factor for this material.
void	setDampingMethod(ElasticContactBase.DampingMethod method) Sets the damping method for this material, which determines how damping forces are compute.
void	setMinThicknessRatio(double r) Sets the minimum thickness ratio for this material.
void	setThickness(double h) Sets the thickness of the foundation layer.
void	setThicknessField(ScalarFieldComponent field) Binds the foundation thickness to a field, or unbinds it if field is null.
void	setUseLocalContactArea(boolean enable) Queries whether local contact areas are used for computing contact pressure.
void	setUseLogDistance(boolean enable) Sets whether log distances are enabled for computing contact forces.
void	writeItems(java.io.PrintWriter pw, NumberFormat fmt, CompositeComponent ancestor)

Methods inherited from class artisynth.core.materials.ContactForceBehavior

computeContactArea, computeResponse, getSubClasses, registerSubclass

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

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

Field Detail

myProps

public static FieldPropertyList myProps

Constructor Detail

ElasticContactBase

public ElasticContactBase()

Need no-args constructor for scanning

Method Detail

getAllPropertyInfo

public FieldPropertyList 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

getThickness

public double getThickness()

Queries the thickness of the foundation layer.

Returns:

foundation layer thickness

setThickness

public void setThickness(double h)

Sets the thickness of the foundation layer.

Parameters:

h - new foundation layer thickness

getThicknessField

public ScalarFieldComponent getThicknessField()

Queries the field, if any, associated with the foundation thickness.

Returns:

thickness field, or null

setThicknessField

public void setThicknessField(ScalarFieldComponent field)

Binds the foundation thickness to a field, or unbinds it if field is null.

Parameters:

field - field to bind to, or null

getMinThicknessRatio

public double getMinThicknessRatio()

Queries the minimum thickness ratio for this material. See setMinThicknessRatio(double).

Returns:

minimum thickness ratio

setMinThicknessRatio

public void setMinThicknessRatio(double r)

Sets the minimum thickness ratio for this material. If contact forces are being generated using log distances, and penetration into the foundation layer exceeds h*(1-r), then the contact force revert to a linear formulation, using the stiffness value at the threshold point. This ensures that restoring forces are still defined even for penetrations through the foundation layer.

Parameters:

r - new minimum thickness ratio

getDampingFactor

public double getDampingFactor()

Queries the damping factor for this material. See setDampingFactor(double).

Returns:

damping factor for this material

setDampingFactor

public void setDampingFactor(double df)

Sets the damping factor for this material. This is this constant multiplier used when computing the damping force. See ElasticContactBase.DampingMethod.

Parameters:

df - new damping factor

getDampingMethod

public ElasticContactBase.DampingMethod getDampingMethod()

Queries the damping method for this material. See setDampingMethod(artisynth.core.materials.ElasticContactBase.DampingMethod).

Returns:

damping method for this material

setDampingMethod

public void setDampingMethod(ElasticContactBase.DampingMethod method)

Sets the damping method for this material, which determines how damping forces are compute. See ElasticContactBase.DampingMethod.

Parameters:

method - new damping method

getUseLogDistance

public boolean getUseLogDistance()

Queries whether log distances are used for computing contact forces. See setUseLogDistance(boolean).

Returns:

true if log distances are used for computing contact forces

setUseLogDistance

public void setUseLogDistance(boolean enable)

Sets whether log distances are enabled for computing contact forces. If enabled, then contact forces increase according to

   ln (1 + d/h)
 

where d is the (negatively valued) penetration distance, and h is the foundation layer thickness. This ensures that forces increase non-linearly to prevent penetration of the foundation layer.

Parameters:

enable - if true, enables using log distances to compute contact forces

getUseLocalContactArea

public boolean getUseLocalContactArea()

Queries whether local contact areas are used for computing contact pressure. See setUseLocalContactArea(boolean).

Returns:

true if local contact areas are used for computing pressure

setUseLocalContactArea

public void setUseLocalContactArea(boolean enable)

Queries whether local contact areas are used for computing contact pressure. If enabled, then within ContactForceBehavior.computeResponse(double[], double, artisynth.core.modelbase.ContactPoint, artisynth.core.modelbase.ContactPoint, maspack.matrix.Vector3d, double, int), the system will attempt to determine the area around each contact using local vertex information for that contact. Otherwise, it will use the value of the contactArea argument.

Parameters:

enable - if true, enables using local contact areas for computing pressure

clone

public ElasticContactBase clone()

Returns a clone of this composite property.

Specified by:

clone in interface CompositeProperty

Specified by:

clone in interface Clonable

Overrides:

clone in class MaterialBase

Returns:

clone of this property

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