This class implements a nonlinear spring ligament model introduced by Blankevoort et al. (1991) [1] and further described in Smith et al. (2016) [2]. More...

Inheritance diagram for OpenSim::Blankevoort1991Ligament:

OpenSim Properties, Sockets, Outputs, Inputs
Properties (unnamed)
GeometryPath	GeometryPath
	"The set of points defining the path of the ligament" More...

Properties (single-value)
double	linear_stiffness
	"The slope of the linear region of the force-strain curve. " "Units of force/strain (N)." More...

double	transition_strain
	"The strain at which the ligament force-strain curve transitions from " "quadratic to linear. Units of strain. Default value of 0.06 (6%)." More...

double	damping_coefficient
	"The coefficient that multiplies the strain rate when computing the " " damping force. Units of N*s/strain. Default value of 0.003." More...

double	slack_length
	"The length at which ligament begins developing tension. Units of m." More...

Outputs
double	spring_force
	Provides the value of getSpringForce() and is available at stage SimTK::Stage::Position . More...

double	damping_force
	Provides the value of getDampingForce() and is available at stage SimTK::Stage::Velocity . More...

double	total_force
	Provides the value of getTotalForce() and is available at stage SimTK::Stage::Velocity . More...

double	strain
	Provides the value of getStrain() and is available at stage SimTK::Stage::Position . More...

double	strain_rate
	Provides the value of getStrainRate() and is available at stage SimTK::Stage::Velocity . More...

double	length
	Provides the value of getLength() and is available at stage SimTK::Stage::Position . More...

double	lengthening_speed
	Provides the value of getLengtheningSpeed() and is available at stage SimTK::Stage::Velocity . More...

OpenSim Properties, Sockets, Outputs, Inputs inherited from OpenSim::Force
bool	appliesForce
	"Flag indicating whether the force is applied or not. If true the force" "is applied to the MultibodySystem otherwise the force is not applied." "NOTE: Prior to OpenSim 4.0, this behavior was controlled by the " "'isDisabled' property, where 'true' meant that force was not being " "applied. Thus, if 'isDisabled' is true, then 'appliesForce` is false." More...

double	potential_energy
	Provides the value of computePotentialEnergy() and is available at stage SimTK::Stage::Velocity . More...

OpenSim Properties, Sockets, Outputs, Inputs inherited from OpenSim::Component
Component	components
	"List of components that this component owns and serializes." More...

Public Member Functions
	Blankevoort1991Ligament ()

	Blankevoort1991Ligament (std::string name, const PhysicalFrame &frame1, SimTK::Vec3 point1, const PhysicalFrame &frame2, SimTK::Vec3 point2)

	Blankevoort1991Ligament (std::string name, const PhysicalFrame &frame1, SimTK::Vec3 point1, const PhysicalFrame &frame2, SimTK::Vec3 point2, double linear_stiffness, double slack_length)

	Blankevoort1991Ligament (std::string name, double linear_stiffness, double slack_length)

void	setSlackLengthFromReferenceStrain (double strain, const SimTK::State &reference_state)
	Set the slack_length property using the strain in the ligament at a known pose (reference state). More...

void	setSlackLengthFromReferenceForce (double force, const SimTK::State &reference_state)
	Set the slack_length property using the absolute spring force (N) in the ligament at a known pose (reference force). More...

void	setLinearStiffnessForcePerLength (double linear_stiffness)
	Set the linear_stiffness property using a value in units of force/length (N/m). More...

void	setDampingCoefficientForceTimePerLength (double damping_coefficient)
	Set the damping_coefficient property using a value in units of forcetime/length (Ns/m). More...

double	getStrain (const SimTK::State &state) const

double	getStrainRate (const SimTK::State &state) const

double	getLength (const SimTK::State &state) const

double	getLengtheningSpeed (const SimTK::State &state) const

double	getSpringForce (const SimTK::State &state) const

double	getDampingForce (const SimTK::State &state) const

double	getTotalForce (const SimTK::State &state) const

double	getLinearStiffnessForcePerLength () const
	Get the linear_stiffness property in units of force/length (N/m) More...

double	getTransitionLength () const
	Get the length (m) of the ligament where the model transitions from the toe region to the linear region. More...

double	getDampingCoefficientForceTimePerLength () const
	Get the damping_coefficient in units of forcetime/length (Ns/m) More...

double	computeMomentArm (const SimTK::State &s, Coordinate &aCoord) const

void	computeForce (const SimTK::State &s, SimTK::Vector_< SimTK::SpatialVec > &bodyForces, SimTK::Vector &generalizedForces) const override
	Subclasses must implement this method to compute the forces that should be applied to bodies and generalized speeds. More...

double	computePotentialEnergy (const SimTK::State &state) const override
	Subclasses may optionally override this method to compute a contribution to the potential energy of the system. More...

void	extendPostScale (const SimTK::State &s, const ScaleSet &scaleSet) override
	Perform any computations that must occur after ModelComponent::scale() has been invoked on all ModelComponents in the Model. More...

OpenSim::Array< std::string >	getRecordLabels () const override
	Methods to query a Force for the value actually applied during simulation. More...

OpenSim::Array< double >	getRecordValues (const SimTK::State &state) const override
	Given SimTK::State object extract all the values necessary to report forces, application location frame, etc. More...

Property-related functions
const GeometryPath &	get_GeometryPath () const
	Get the value of the GeometryPath property. More...

GeometryPath &	upd_GeometryPath ()
	Get a writable reference to the GeometryPath property. More...

void	set_GeometryPath (const GeometryPath &value)
	Set the value of the GeometryPath property. More...

const double &	get_linear_stiffness () const
	Get the value of the linear_stiffness property. More...

double &	upd_linear_stiffness ()
	Get a writable reference to the linear_stiffness property. More...

void	set_linear_stiffness (const double &value)
	Set the value of the linear_stiffness property. More...

const double &	get_transition_strain () const
	Get the value of the transition_strain property. More...

double &	upd_transition_strain ()
	Get a writable reference to the transition_strain property. More...

void	set_transition_strain (const double &value)
	Set the value of the transition_strain property. More...

const double &	get_damping_coefficient () const
	Get the value of the damping_coefficient property. More...

double &	upd_damping_coefficient ()
	Get a writable reference to the damping_coefficient property. More...

void	set_damping_coefficient (const double &value)
	Set the value of the damping_coefficient property. More...

const double &	get_slack_length () const
	Get the value of the slack_length property. More...

double &	upd_slack_length ()
	Get a writable reference to the slack_length property. More...

void	set_slack_length (const double &value)
	Set the value of the slack_length property. More...

Public Member Functions inherited from OpenSim::Force
virtual bool	shouldBeParallelized () const
	Tell SimBody to parallelize this force. More...

bool	appliesForce (const SimTK::State &s) const
	Return if the Force is applied (or enabled) or not. More...

void	setAppliesForce (SimTK::State &s, bool applyForce) const
	Set whether or not the Force is applied. More...

virtual bool	hasGeometryPath () const
	Return a flag indicating whether the Force is applied along a Path. More...

const bool &	get_appliesForce () const
	Get the value of the appliesForce property. More...

bool &	upd_appliesForce ()
	Get a writable reference to the appliesForce property. More...

void	set_appliesForce (const bool &value)
	Set the value of the appliesForce property. More...

Public Member Functions inherited from OpenSim::ModelComponent
	ModelComponent ()
	Default constructor. More...

	ModelComponent (const std::string &aFileName, bool aUpdateFromXMLNode=true)
	Construct ModelComponent from an XML file. More...

	ModelComponent (SimTK::Xml::Element &aNode)
	Construct ModelComponent from a specific node in an XML document. More...

virtual	~ModelComponent ()
	Destructor is virtual to allow concrete model component cleanup. More...

void	connectToModel (Model &model)
	Connect this ModelComponent to its aggregate- a Model. More...

const Model &	getModel () const
	Get a const reference to the Model this component is part of. More...

Model &	updModel ()
	Get a modifiable reference to the Model this component is part of. More...

bool	hasModel () const
	Does this ModelComponent have a Model associated with it? More...

void	preScale (const SimTK::State &s, const ScaleSet &scaleSet)
	Perform any computations that must occur before ModelComponent::scale() is invoked on all ModelComponents in the Model. More...

void	scale (const SimTK::State &s, const ScaleSet &scaleSet)
	Scale the ModelComponent. More...

void	postScale (const SimTK::State &s, const ScaleSet &scaleSet)
	Perform any computations that must occur after ModelComponent::scale() has been invoked on all ModelComponents in the Model. More...

Public Member Functions inherited from OpenSim::Component
	Component ()
	Default constructor. More...

	Component (const std::string &aFileName, bool aUpdateFromXMLNode=true)
	Construct Component from an XML file. More...

	Component (SimTK::Xml::Element &aNode)
	Construct Component from a specific node in an XML document. More...

	Component (const Component &)=default
	Use default copy constructor and assignment operator. More...

Component &	operator= (const Component &)=default

virtual	~Component ()=default
	Destructor is virtual to allow concrete Component to cleanup. More...

virtual void	generateDecorations (bool fixed, const ModelDisplayHints &hints, const SimTK::State &state, SimTK::Array_< SimTK::DecorativeGeometry > &appendToThis) const
	Optional method for generating arbitrary display geometry that reflects this Component at the specified state. More...

const SimTK::MultibodySystem &	getSystem () const
	Get the underlying MultibodySystem that this component is connected to. More...

bool	hasSystem () const
	Check if this component has an underlying MultibodySystem. More...

bool	isComponentInOwnershipTree (const Component *component) const
	Does the provided component already exist anywhere in the ownership tree (not just subcomponents of this component)? More...

void	addComponent (Component *subcomponent)
	Add a Component (as a subcomponent) of this component. More...

template<typename T = Component>
ComponentList< const T >	getComponentList () const
	Get an iterator through the underlying subcomponents that this component is composed of. More...

template<typename T = Component>
ComponentList< T >	updComponentList ()
	Similar to getComponentList(), except the resulting list allows one to modify the components. More...

template<typename T = Component>
unsigned	countNumComponents () const
	Uses getComponentList<T>() to count the number of underlying subcomponents of the specified type. More...

std::string	getAbsolutePathString () const
	Get the complete (absolute) pathname for this Component to its ancestral Component, which is the root of the tree to which this Component belongs. More...

ComponentPath	getAbsolutePath () const
	Return a ComponentPath of the absolute path of this Component. More...

std::string	getRelativePathString (const Component &wrt) const
	Get the relative path of this Component with respect to another Component, as a string. More...

ComponentPath	getRelativePath (const Component &wrt) const
	Get the relative path of this Component with respect to another Component. More...

bool	hasComponent (const std::string &pathname) const
	Query if there is a component (of any type) at the specified path name. More...

template<class C = Component>
bool	hasComponent (const std::string &pathname) const
	Query if there is a component of a given type at the specified path name. More...

template<class C = Component>
const C &	getComponent (const std::string &pathname) const
	Get a unique subcomponent of this Component by its path name and type 'C'. More...

template<class C = Component>
const C &	getComponent (const ComponentPath &pathname) const

const Component &	getComponent (const std::string &pathname) const
	Similar to the templatized getComponent(), except this returns the component as the generic Component type. More...

template<class C = Component>
C &	updComponent (const std::string &name)
	Get a writable reference to a subcomponent. More...

template<class C = Component>
C &	updComponent (const ComponentPath &name)

Component &	updComponent (const std::string &pathname)
	Similar to the templatized updComponent(), except this returns the component as the generic Component type. More...

unsigned	printComponentsMatching (const std::string &substring) const
	Print a list to the console of all components whose absolute path name contains the given string. More...

int	getNumStateVariables () const
	Get the number of "continuous" state variables maintained by the Component and its subcomponents. More...

Array< std::string >	getStateVariableNames () const
	Get the names of "continuous" state variables maintained by the Component and its subcomponents. More...

template<class C = Component>
const C *	findComponent (const ComponentPath &pathToFind) const
	Find a Component to which this Component is an ancestor—in other words, a Component that is directly owned by this Component or is owned by one of its sub-components, sub-sub-components, etc. More...

template<class C = Component>
const C *	findComponent (const std::string &pathToFind) const
	Same as findComponent(const ComponentPath&), but accepting a string (a path or just a name) as input. More...

const StateVariable *	traverseToStateVariable (const std::string &pathName) const
	Get a StateVariable anywhere in the Component tree, given a StateVariable path. More...

void	finalizeFromProperties ()
	Define a Component's internal data members and structure according to its properties. More...

void	finalizeConnections (Component &root)
	Satisfy the Component's connections specified by its Sockets and Inputs. More...

void	clearConnections ()
	Disconnect/clear this Component from its aggregate component. More...

void	addToSystem (SimTK::MultibodySystem &system) const
	Have the Component add itself to the underlying computational System. More...

void	initStateFromProperties (SimTK::State &state) const
	Initialize Component's state variable values from its properties. More...

void	setPropertiesFromState (const SimTK::State &state)
	Set Component's properties given a state. More...

int	getNumSockets () const
	Get the number of Sockets in this Component. More...

std::vector< std::string >	getSocketNames ()
	Collect and return the names of the sockets in this component. More...

template<typename T >
const T &	getConnectee (const std::string &name) const
	Get the "connectee" object that the Component's Socket is bound to. More...

const Object &	getConnectee (const std::string &name) const
	Get the connectee as an Object. More...

const AbstractSocket &	getSocket (const std::string &name) const
	Get an AbstractSocket for the given socket name. More...

AbstractSocket &	updSocket (const std::string &name)
	Get a writable reference to the AbstractSocket for the given socket name. More...

template<typename T >
const Socket< T > &	getSocket (const std::string &name) const
	Get a const reference to the concrete Socket provided by this Component by name. More...

template<typename T >
Socket< T > &	updSocket (const std::string &name)
	Get a writable reference to the concrete Socket provided by this Component by name. More...

void	printSubcomponentInfo () const
	List all subcomponents by name and recurse into these components to list their subcomponents, and so on. More...

void	printSocketInfo () const
	List all the Sockets of this component and whether or not they are connected. More...

void	printInputInfo () const
	List all the inputs of this component and whether or not they are connected. More...

template<typename C >
void	printSubcomponentInfo () const

void	printOutputInfo (const bool includeDescendants=true) const
	Print outputs of this component and optionally, those of all subcomponents. More...

int	getNumInputs () const
	Access the number of Inputs that this component has. More...

int	getNumOutputs () const
	Access the number of Outputs that this component has. More...

std::vector< std::string >	getInputNames () const
	Collect and return the names of Inputs in this component as an std::vector. More...

std::vector< std::string >	getOutputNames () const
	Collect and return the names of Outputs in this component as an std::vector. More...

const AbstractInput &	getInput (const std::string &name) const
	Get an Input provided by this Component by name. More...

AbstractInput &	updInput (const std::string &name)
	Get a writable reference to an Input provided by this Component by name. More...

template<typename T >
const Input< T > &	getInput (const std::string &name) const
	Get a concrete Input that you can directly ask for its values. More...

const AbstractOutput &	getOutput (const std::string &name) const
	Get the Output provided by this Component by name. More...

AbstractOutput &	updOutput (const std::string &name)
	Get a writable reference to an Output provided by this Component by name. More...

SimTK::IteratorRange< OutputConstIterator >	getOutputs () const
	Iterate through all Outputs of this component. More...

int	getModelingOption (const SimTK::State &state, const std::string &name) const
	Get a ModelingOption flag for this Component by name. More...

void	setModelingOption (SimTK::State &state, const std::string &name, int flag) const
	Set the value of a ModelingOption flag for this Component. More...

template<typename T >
const T &	getInputValue (const SimTK::State &state, const std::string &name) const
	Get the Input value that this component is dependent on. More...

template<typename T >
const T &	getOutputValue (const SimTK::State &state, const std::string &name) const
	Get the Output value provided by this Component by name. More...

double	getStateVariableValue (const SimTK::State &state, const std::string &name) const
	Get the value of a state variable allocated by this Component. More...

void	setStateVariableValue (SimTK::State &state, const std::string &name, double value) const
	Set the value of a state variable allocated by this Component by name. More...

SimTK::Vector	getStateVariableValues (const SimTK::State &state) const
	Get all values of the state variables allocated by this Component. More...

void	setStateVariableValues (SimTK::State &state, const SimTK::Vector &values) const
	Set all values of the state variables allocated by this Component. More...

double	getStateVariableDerivativeValue (const SimTK::State &state, const std::string &name) const
	Get the value of a state variable derivative computed by this Component. More...

double	getDiscreteVariableValue (const SimTK::State &state, const std::string &name) const
	Get the value of a discrete variable allocated by this Component by name. More...

void	setDiscreteVariableValue (SimTK::State &state, const std::string &name, double value) const
	Set the value of a discrete variable allocated by this Component by name. More...

template<class T >
SimTK::CacheEntryIndex	getCacheVariableIndex (const CacheVariable< T > &cv) const
	Get the index of a Component's cache variable in the Subsystem for allocations. More...

SimTK::CacheEntryIndex	getCacheVariableIndex (const std::string &name) const
	Get the index of a Component's cache variable in the Subsystem for allocations. More...

template<class T >
const T &	getCacheVariableValue (const SimTK::State &state, const std::string &name) const
	Get the value of a cache variable allocated by this Component by name. More...

template<class T >
const T &	getCacheVariableValue (const SimTK::State &state, const CacheVariable< T > &cv) const
	Get the value of a cache variable allocated by this Component. More...

template<typename T >
void	setCacheVariableValue (const SimTK::State &state, const std::string &k, T value) const
	Set the value of a cache variable, identified by `name`, to a new value and mark the cache variable as valid. More...

template<typename T >
void	setCacheVariableValue (const SimTK::State &state, const CacheVariable< T > &cv, T value) const
	Set the value of a cache variable to a new value and mark the cache variable as valid. More...

template<typename T >
T &	updCacheVariableValue (const SimTK::State &state, const std::string &name) const
	Returns a mutable reference to the value of a cache variable identified by `name`. More...

template<typename T >
T &	updCacheVariableValue (const SimTK::State &state, const CacheVariable< T > &cv) const
	Returns a mutable reference to the value of a cache variable. More...

bool	isCacheVariableValid (const SimTK::State &state, const std::string &name) const
	Returns true if the cache variable, identified by `name`, is valid. More...

template<class T >
bool	isCacheVariableValid (const SimTK::State &state, const CacheVariable< T > &cv) const
	Returns true if the cache variable is valid. More...

void	markCacheVariableValid (const SimTK::State &state, const std::string &name) const
	Marks the value of a cache variable, identified by `name`, as valid. More...

template<typename T >
void	markCacheVariableValid (const SimTK::State &state, const CacheVariable< T > &cv) const
	Marks the value of a cache variable as valid. More...

void	markCacheVariableInvalid (const SimTK::State &state, const std::string &name) const
	Marks the value of a cache variable, identified by `name`, as invalid. More...

template<class T >
void	markCacheVariableInvalid (const SimTK::State &state, const CacheVariable< T > &cv) const
	Marks the value of a cache variable as invalid. More...

const Component &	getOwner () const
	Access the owner of this Component. More...

bool	hasOwner () const
	(For advanced users) Check if this Component has an owner. More...

const Component &	getRoot () const
	Obtain the root Component, which is this component if it is orphaned. More...

Public Member Functions inherited from OpenSim::Object
virtual	~Object ()
	Virtual destructor for cleanup. More...

bool	isEqualTo (const Object &aObject) const
	Equality operator wrapper for use from languages not supporting operator overloading. More...

Object &	operator= (const Object &aObject)
	Copy assignment copies he base class fields, including the properties. More...

virtual bool	operator== (const Object &aObject) const
	Determine if two objects are equal. More...

virtual bool	operator< (const Object &aObject) const
	Provide an ordering for objects so they can be put in sorted containers. More...

void	setName (const std::string &name)
	Set the name of the Object. More...

const std::string &	getName () const
	Get the name of this Object. More...

void	setDescription (const std::string &description)
	Set description, a one-liner summary. More...

const std::string &	getDescription () const
	Get description, a one-liner summary. More...

const std::string &	getAuthors () const
	Get Authors of this Object. More...

void	setAuthors (const std::string &authors)
	Set Authors of this object. More...

const std::string &	getReferences () const
	Get references or publications to cite if using this object. More...

void	setReferences (const std::string &references)
	Set references or publications to cite if using this object. More...

int	getNumProperties () const
	Determine how many properties are stored with this Object. More...

const AbstractProperty &	getPropertyByIndex (int propertyIndex) const
	Get a const reference to a property by its index number, returned as an AbstractProperty. More...

AbstractProperty &	updPropertyByIndex (int propertyIndex)
	Get a writable reference to a property by its index number, returned as an AbstractProperty. More...

bool	hasProperty (const std::string &name) const
	Return true if this Object has a property of any type with the given name, which must not be empty. More...

const AbstractProperty &	getPropertyByName (const std::string &name) const
	Get a const reference to a property by its name, returned as an AbstractProperty. More...

AbstractProperty &	updPropertyByName (const std::string &name)
	Get a writable reference to a property by its name, returned as an AbstractProperty. More...

template<class T >
bool	hasProperty () const
	Return true if this Object contains an unnamed, one-object property that contains objects of the given template type T. More...

template<class T >
const Property< T > &	getProperty (const PropertyIndex &index) const
	Get property of known type Property<T> as a const reference; the property must be present and have the right type. More...

template<class T >
Property< T > &	updProperty (const PropertyIndex &index)
	Get property of known type Property<T> as a writable reference; the property must be present and have the right type. More...

bool	isObjectUpToDateWithProperties () const
	Returns `true` if no property's value has changed since the last time setObjectIsUpToDateWithProperties() was called. More...

void	readObjectFromXMLNodeOrFile (SimTK::Xml::Element &objectElement, int versionNumber)
	We're given an XML element from which we are to populate this Object. More...

void	updateXMLNode (SimTK::Xml::Element &parent, const AbstractProperty *prop=nullptr) const
	Serialize this object into the XML node that represents it. More...

bool	getInlined () const
	Inlined means an in-memory Object that is not associated with an XMLDocument. More...

void	setInlined (bool aInlined, const std::string &aFileName="")
	Mark this as inlined or not and optionally provide a file name to associate with the new XMLDocument for the non-inline case. More...

std::string	getDocumentFileName () const
	If there is a document associated with this object then return the file name maintained by the document. More...

int	getDocumentFileVersion () const
	If there is a document associated with this object then return its version number. More...

void	setAllPropertiesUseDefault (bool aUseDefault)

bool	print (const std::string &fileName) const
	Write this Object into an XML file of the given name; conventionally the suffix to use is ".osim". More...

std::string	dump () const
	dump the XML representation of this Object into an std::string and return it. More...

virtual bool	isA (const char *type) const
	The default implementation returns true only if the supplied string is "Object"; each Object-derived class overrides this to match its own class name. More...

const std::string &	toString () const
	Wrapper to be used on Java side to display objects in tree; this returns just the object's name. More...

PropertySet &	getPropertySet ()
	OBSOLETE: Get a reference to the PropertySet maintained by the Object. More...

const PropertySet &	getPropertySet () const

Auto-generated functions
static Blankevoort1991Ligament *	safeDownCast (OpenSim::Object *obj)
	For use in MATLAB and Python to access the concrete class. More...

static const std::string &	getClassName ()
	This returns "Blankevoort1991Ligament". More...

Blankevoort1991Ligament *	clone () const override
	Create a new heap-allocated copy of the concrete object to which this Object refers. More...

const std::string &	getConcreteClassName () const override
	Returns the class name of the concrete Object-derived class of the actual object referenced by this Object, as a string. More...

Additional Inherited Members
Static Public Member Functions inherited from OpenSim::Force
static Force *	safeDownCast (OpenSim::Object *obj)
	For use in MATLAB and Python to access the concrete class. More...

static const std::string &	getClassName ()
	This returns "Force". More...

Static Public Member Functions inherited from OpenSim::ModelComponent
static ModelComponent *	safeDownCast (OpenSim::Object *obj)
	For use in MATLAB and Python to access the concrete class. More...

static const std::string &	getClassName ()
	This returns "ModelComponent". More...

Static Public Member Functions inherited from OpenSim::Component
static Component *	safeDownCast (OpenSim::Object *obj)
	For use in MATLAB and Python to access the concrete class. More...

static const std::string &	getClassName ()
	This returns "Component". More...

Static Public Member Functions inherited from OpenSim::Object
static void	registerType (const Object &defaultObject)
	Register an instance of a class; if the class is already registered it will be replaced. More...

static void	renameType (const std::string &oldTypeName, const std::string &newTypeName)
	Support versioning by associating the current Object type with an old name. More...

static const Object *	getDefaultInstanceOfType (const std::string &concreteClassName)
	Return a pointer to the default instance of the registered (concrete) Object whose class name is given, or NULL if the type is not registered. More...

template<class T >
static bool	isObjectTypeDerivedFrom (const std::string &concreteClassName)
	Return true if the given concrete object type represents a subclass of the template object type T, and thus could be referenced with a T*. More...

static Object *	newInstanceOfType (const std::string &concreteClassName)
	Create a new instance of the concrete Object type whose class name is given as concreteClassName. More...

static void	getRegisteredTypenames (Array< std::string > &typeNames)
	Retrieve all the typenames registered so far. More...

template<class T >
static void	getRegisteredObjectsOfGivenType (ArrayPtrs< T > &rArray)
	Return an array of pointers to the default instances of all registered (concrete) Object types that derive from a given Object-derived type that does not have to be concrete. More...

static bool	PrintPropertyInfo (std::ostream &os, const std::string &classNameDotPropertyName, bool printFlagInfo=true)
	Dump formatted property information to a given output stream, useful for creating a "help" facility for registered objects. More...

static bool	PrintPropertyInfo (std::ostream &os, const std::string &className, const std::string &propertyName, bool printFlagInfo=true)
	Same as the other signature but the class name and property name are provided as two separate strings. More...

static Object *	makeObjectFromFile (const std::string &fileName)
	Create an OpenSim object whose type is based on the tag at the root node of the XML file passed in. More...

static const std::string &	getClassName ()
	Return the name of this class as a string; i.e., "Object". More...

static void	setSerializeAllDefaults (bool shouldSerializeDefaults)
	Static function to control whether all registered objects and their properties are written to the defaults section of output files rather than only those values for which the default was explicitly overwritten when read in from an input file or set programmatically. More...

static bool	getSerializeAllDefaults ()
	Report the value of the "serialize all defaults" flag. More...

static bool	isKindOf (const char *type)
	Returns true if the passed-in string is "Object"; each Object-derived class defines a method of this name for its own class name. More...

static void	setDebugLevel (int newLevel)
	Set the amount of logging output. More...

static int	getDebugLevel ()
	Get the current setting of debug level. More...

static Object *	SafeCopy (const Object *aObject)
	Use the clone() method to duplicate the given object unless the pointer is null in which case null is returned. More...

static void	RegisterType (const Object &defaultObject)
	OBSOLETE alternate name for registerType(). More...

static void	RenameType (const std::string &oldName, const std::string &newName)
	OBSOLETE alternate name for renameType(). More...

Detailed Description

This class implements a nonlinear spring ligament model introduced by Blankevoort et al. (1991) [1] and further described in Smith et al. (2016) [2].

This model is partially based on the formulation orginally proposed by Wismans et al. (1980) [3]. The ligament is represented as a passive spring with the force-strain relationship described by a quadratic "toe" region at low strains and a linear region at high strains. The toe region represents the uncrimping and alignment of collagen fibers and the linear region represents the subsequent stretching of the aligned fibers. The ligament model also includes a damping force that is only applied if the ligament is stretched beyond the slack length and if the ligament is lengthening. The length of the ligament is \( l \).

Governing Equations

Spring Force:

\[ F_{\mathrm{spring}} = \begin{Bmatrix} 0 & \epsilon < 0 \\ \frac{1}{2\epsilon_t }k\epsilon^2 & 0 \leq \epsilon \leq \epsilon_t \\ k(\epsilon - \frac{\epsilon_t}{2})& \epsilon > \epsilon_t \end{Bmatrix} \]

Damping Force:

\[ F_{\mathrm{damping}} = \begin{Bmatrix} c\cdot \dot{\epsilon} & \epsilon > 0 \: and \: \dot{\epsilon} > 0 \\ 0 & otherwise \end{Bmatrix} \]

Total Force:

\[ F_{\mathrm{total}} = F_{\mathrm{spring}} + F_{\mathrm{damping}} \]

This Force component has the following properties:

linear stiffness (k): The force/strain (e.g. N) stiffness of the linear region of the ligament model.
slack_length ( \(l_0\)): The resting length of the ligament (e.g. m).
damping coefficient (c): Damping coefficient used in the damping force calculation in units of force*time/strain (e.g. N*s/strain). The default value is 0.003.
transition_strain ( \(\epsilon_t\)): The strain value where the ligament model transitions from the quadratic toe region to the linear stiffness region. The default value is 0.06 (6%) according to Blankevoort (1991) [1]. This value is widely used in the multibody knee modeling literature [2,4,5,6] and also agrees with some experimental studies [7]. However, other literature suggests the transition strain of ligaments occurs at around 0.03 (3%) strain [8,9]. In reality, the transition strain is likely dependent on the strain rate [10,11], however this effect is not included in this implementation.

The Blankevoort1991Ligament implementation is intended to be compatible with common methods in the literature for parameterizing ligament properties. The zero-load length of the ligament is parameterized by the slack_length property, which can be set directly, in meters, using set_slack_length(), or using setSlackLengthFromReferenceStrain() and setSlackLengthFromReferenceForce(). Here, reference strain and reference force are the strain or force in the ligament at a reference pose (state). If you want to compute the strain or force of the ligament in a given pose (state), you can use the getStrain() and getForce() methods. The linear_stiffness property has units of force/strain (newton) but can be set and obtained in units of force/length (newton/meter) using setLinearStiffnessForcePerLength() and getLinearStiffnessForcePerLength().

When scaling a model (using the ScaleTool) that contains a Blankevoort1991Ligament, the slack_length property is scaled by the ratio of the entire GeometryPath length in the default model pose before and after scaling the bone geometries. This ensures that the strain in the ligament in the default pose is equivilent before and after scaling. Thus, it is important to consider the order of scaling the model and setting the slack_length property for your specific application. The linear_stiffness property is not affected by scaling the model.

[1] Blankevoort, L. and Huiskes, R., (1991). Ligament-bone interaction in a three-dimensional model of the knee. J Biomech Eng, 113(3), 263-269

[2] Smith, C.R., Lenhart, R.L., Kaiser, J., Vignos, M.F. and Thelen, D.G., (2016). Influence of ligament properties on tibiofemoral mechanics in walking. J Knee Surg, 29(02), 99-106.

[3] Wismans, J.A.C., Veldpaus, F., Janssen, J., Huson, A. and Struben, P., (1980). A three-dimensional mathematical model of the knee-joint. J Biomech, 13(8), 677-685.

[4] Marra, M. A., Vanheule, V., Fluit, R., Koopman, B. H., Rasmussen, J., Verdonschot, N., & Andersen, M. S. (2015). A subject-specific musculoskeletal modeling framework to predict in vivo mechanics of total knee arthroplasty. Journal of biomechanical engineering, 137(2), 020904.

[5] Guess, T. M., Razu, S., & Jahandar, H. (2016). Evaluation of knee ligament mechanics using computational models. The journal of knee surgery, 29(02), 126-137.

[6] Li, G., Gil, J., Kanamori, A., & Woo, S. Y. (1999). A validated three-dimensional computational model of a human knee joint. Journal of biomechanical engineering, 121(6), 657-662.

[7] Ristaniemi, A., Stenroth, L., Mikkonen, S., & Korhonen, R. K. (2018). Comparison of elastic, viscoelastic and failure tensile material properties of knee ligaments and patellar tendon. Journal of biomechanics, 79, 31-38.

[8] Weiss, J. A., & Gardiner, J. C. (2001). Computational modeling of ligament mechanics. Critical Reviews in Biomedical Engineering, 29(3).

[9] Martin, R. B., Burr, D. B., Sharkey, N. A., & Fyhrie, D. P. (2015). Mechanical properties of ligament and tendon. In Skeletal Tissue Mechanics (pp. 175-225). Springer, New York, NY.

[10] Pioletti, D. P., Rakotomanana, L. R., Benvenuti, J. F., & Leyvraz, P. F. (1998). Viscoelastic constitutive law in large deformations: application to human knee ligaments and tendons. Journal of biomechanics, 31(8), 753-757.

[11] Pioletti, D. P., Rakotomanana, L. R., & Leyvraz, P. F. (1999). Strain rate effect on the mechanical behavior of the anterior cruciate ligament-bone complex. Medical Engineering & Physics, 21(2), 95-100.

[12] Galbusera, F., Freutel, M., Durselen, L., D'Aiuto, M., Croce, D., Villa, T., Sansone, V. & Innocenti, B. (2014). Material models and properties in the finite element analysis of knee ligaments: a literature review. Frontiers in bioengineering and biotechnology, 2, 54.

Author: Colin Smith

Constructor & Destructor Documentation

◆ Blankevoort1991Ligament() [1/4]

OpenSim::Blankevoort1991Ligament::Blankevoort1991Ligament ( )

◆ Blankevoort1991Ligament() [2/4]

OpenSim::Blankevoort1991Ligament::Blankevoort1991Ligament	(	std::string	name,
		const PhysicalFrame &	frame1,
		SimTK::Vec3	point1,
		const PhysicalFrame &	frame2,
		SimTK::Vec3	point2
	)

◆ Blankevoort1991Ligament() [3/4]

OpenSim::Blankevoort1991Ligament::Blankevoort1991Ligament	(	std::string	name,
		const PhysicalFrame &	frame1,
		SimTK::Vec3	point1,
		const PhysicalFrame &	frame2,
		SimTK::Vec3	point2,
		double	linear_stiffness,
		double	slack_length
	)

◆ Blankevoort1991Ligament() [4/4]

OpenSim::Blankevoort1991Ligament::Blankevoort1991Ligament	(	std::string	name,
		double	linear_stiffness,
		double	slack_length
	)

Member Function Documentation

◆ calcDampingForce()

double OpenSim::Blankevoort1991Ligament::calcDampingForce ( const SimTK::State & state ) const

protected

◆ calcInverseForceStrainCurve()

double OpenSim::Blankevoort1991Ligament::calcInverseForceStrainCurve ( double force ) const

protected

◆ calcSpringForce()

double OpenSim::Blankevoort1991Ligament::calcSpringForce ( const SimTK::State & state ) const

protected

◆ calcTotalForce()

double OpenSim::Blankevoort1991Ligament::calcTotalForce ( const SimTK::State & state ) const

protected

◆ clone()

Blankevoort1991Ligament* OpenSim::Blankevoort1991Ligament::clone ( ) const

inlineoverridevirtual

Create a new heap-allocated copy of the concrete object to which this Object refers.

It is up to the caller to delete the returned object when no longer needed. Every concrete object deriving from Object implements this pure virtual method automatically, via the declaration macro it invokes (e.g., OpenSim_DECLARE_CONCRETE_OBJECT()). Note that the concrete class overrides modify the return type to be a pointer to the concrete object; that still overrides the base class method because the return type is covariant with (that is, derives from) Object.

Implements OpenSim::Force.

◆ computeForce()

void OpenSim::Blankevoort1991Ligament::computeForce	(	const SimTK::State &	state,
		SimTK::Vector_< SimTK::SpatialVec > &	bodyForces,
		SimTK::Vector &	generalizedForces
	)		const

overridevirtual

Subclasses must implement this method to compute the forces that should be applied to bodies and generalized speeds.

This is invoked by ForceAdapter to perform the force computation.

Reimplemented from OpenSim::Force.

◆ computeMomentArm()

double OpenSim::Blankevoort1991Ligament::computeMomentArm	(	const SimTK::State &	s,
		Coordinate &	aCoord
	)		const

◆ computePotentialEnergy()

double OpenSim::Blankevoort1991Ligament::computePotentialEnergy ( const SimTK::State & state ) const

overridevirtual

Subclasses may optionally override this method to compute a contribution to the potential energy of the system.

The default implementation returns 0, which is appropriate for forces that do not contribute to potential energy.

Reimplemented from OpenSim::Force.

◆ extendAddToSystem()

void OpenSim::Blankevoort1991Ligament::extendAddToSystem ( SimTK::MultibodySystem & system ) const

overrideprotectedvirtual

Add appropriate Simbody elements (if needed) to the System corresponding to this component and specify needed state resources.

extendAddToSystem() is called when the Simbody System is being created to represent a completed system (model) for computation. That is, connect() will already have been invoked on all components before any addToSystem() call is made. Helper methods for adding modeling options, state variables and their derivatives, discrete variables, and cache entries are available and can be called within extendAddToSystem() only.

Note that this method is const; you may not modify your model component or the containing model during this call. Any modifications you need should instead be performed in finalizeFromProperties() or at the latest connect(), which are non-const. The only exception is that you may need to record access information for resources you create in the system, such as an index number. For most Components, OpenSim base classes either provide convenience methods or handle indices automatically. Otherwise, you must declare indices as mutable data members so that you can set them here.

If you override this method, be sure to invoke the base class method at the beginning, using code like this:

void MyComponent::extendAddToSystem(SimTK::MultibodySystem& system) const {
    // Perform any additions to the system required by your Super
    Super::extendAddToSystem(system);
    // ... your code goes here
}

This method assumes that this Component's addToSystem will be invoked before its subcomponents. If you need your subcomponents to be added to the system, first (e.g. require of a Force to be anchored to a SimTK::MobilizedBody specified by subcomponents) then you must implement: extendAddToSystemAfterSubcomponents(). It is possible to implement both method to add system elements before and then after your subcomponents have added themselves. Caution is required that Simbody elements are not added twice especially when order is unimportant.

Parameters

[in,out] system The MultibodySystem being added to.

See also: addModelingOption(), addStateVariable(), addDiscreteVariables(), addCacheVariable()

Reimplemented from OpenSim::Component.

◆ extendFinalizeFromProperties()

void OpenSim::Blankevoort1991Ligament::extendFinalizeFromProperties ( )

overrideprotectedvirtual

Perform any time-invariant calculations, data structure initializations, or other configuration based on the component's properties to form a functioning (but not yet connected) component.

For example, each property should be checked to ensure that its value is within an acceptable range. When this method returns, the component will be marked as being up-to-date with its properties. Do not perform any configuration that depends on the SimTK::MultibodySystem; it is not available at this point.

If you override this method, be sure to invoke the base class method first, using code like this:

void MyComponent::extendFinalizeFromProperties() {
    Super::extendFinalizeFromProperties(); // invoke parent class method
    // ... your code goes here
    // ... catch invalid property values
    // ... initialize any internal data structures
}

Reimplemented from OpenSim::Component.

◆ extendPostScale()

void OpenSim::Blankevoort1991Ligament::extendPostScale	(	const SimTK::State &	s,
		const ScaleSet &	scaleSet
	)

overridevirtual

Perform any computations that must occur after ModelComponent::scale() has been invoked on all ModelComponents in the Model.

This method is virtual and may be implemented by any subclass of ModelComponent, but all implementations must begin with a call to Super::extendPostScale() to execute the parent class methods before the child class method. The base class implementation in ModelComponent does nothing.

See also: postScale()

Reimplemented from OpenSim::ModelComponent.

◆ get_damping_coefficient()

const double& OpenSim::Blankevoort1991Ligament::get_damping_coefficient ( ) const

inline

Get the value of the damping_coefficient property.

◆ get_GeometryPath()

const GeometryPath& OpenSim::Blankevoort1991Ligament::get_GeometryPath ( ) const

inline

Get the value of the GeometryPath property.

◆ get_linear_stiffness()

const double& OpenSim::Blankevoort1991Ligament::get_linear_stiffness ( ) const

inline

Get the value of the linear_stiffness property.

◆ get_slack_length()

const double& OpenSim::Blankevoort1991Ligament::get_slack_length ( ) const

inline

Get the value of the slack_length property.

◆ get_transition_strain()

const double& OpenSim::Blankevoort1991Ligament::get_transition_strain ( ) const

inline

Get the value of the transition_strain property.

◆ getClassName()

static const std::string& OpenSim::Blankevoort1991Ligament::getClassName ( )

inlinestatic

This returns "Blankevoort1991Ligament".

See getConcreteClassName() if you want the class name of the underlying concrete object instead.

◆ getConcreteClassName()

const std::string& OpenSim::Blankevoort1991Ligament::getConcreteClassName ( ) const

inlineoverridevirtual

Returns the class name of the concrete Object-derived class of the actual object referenced by this Object, as a string.

This is the string that is used as the tag for this concrete object in an XML file. Every concrete class derived from Object automatically overrides this method via the declaration macro it uses. See getClassName() to get the class name of the referencing (possibly abstract) class rather than the concrete object.

See also: getClassName()

Implements OpenSim::Force.

◆ getDampingCoefficientForceTimePerLength()

double OpenSim::Blankevoort1991Ligament::getDampingCoefficientForceTimePerLength ( ) const

Get the damping_coefficient in units of force*time/length (N*s/m)

◆ getDampingForce()

double OpenSim::Blankevoort1991Ligament::getDampingForce ( const SimTK::State & state ) const

◆ getLength()

double OpenSim::Blankevoort1991Ligament::getLength ( const SimTK::State & state ) const

◆ getLengtheningSpeed()

double OpenSim::Blankevoort1991Ligament::getLengtheningSpeed ( const SimTK::State & state ) const

◆ getLinearStiffnessForcePerLength()

double OpenSim::Blankevoort1991Ligament::getLinearStiffnessForcePerLength ( ) const

Get the linear_stiffness property in units of force/length (N/m)

◆ getRecordLabels()

OpenSim::Array<std::string> OpenSim::Blankevoort1991Ligament::getRecordLabels ( ) const

overridevirtual

Methods to query a Force for the value actually applied during simulation.

The names of the quantities (column labels) is returned by this first function getRecordLabels().

Reimplemented from OpenSim::Force.

◆ getRecordValues()

OpenSim::Array<double> OpenSim::Blankevoort1991Ligament::getRecordValues ( const SimTK::State & state ) const

overridevirtual

Given SimTK::State object extract all the values necessary to report forces, application location frame, etc.

used in conjunction with getRecordLabels and should return same size Array.

Reimplemented from OpenSim::Force.

◆ getSpringForce()

double OpenSim::Blankevoort1991Ligament::getSpringForce ( const SimTK::State & state ) const

◆ getStrain()

double OpenSim::Blankevoort1991Ligament::getStrain ( const SimTK::State & state ) const

◆ getStrainRate()

double OpenSim::Blankevoort1991Ligament::getStrainRate ( const SimTK::State & state ) const

◆ getTotalForce()

double OpenSim::Blankevoort1991Ligament::getTotalForce ( const SimTK::State & state ) const

◆ getTransitionLength()

double OpenSim::Blankevoort1991Ligament::getTransitionLength ( ) const

Get the length (m) of the ligament where the model transitions from the toe region to the linear region.

This corresponds to the length of the ligament at the transistion_strain.

◆ safeDownCast()

static Blankevoort1991Ligament* OpenSim::Blankevoort1991Ligament::safeDownCast ( OpenSim::Object * obj )

inlinestatic

For use in MATLAB and Python to access the concrete class.

Example: cObj = Blankevoort1991Ligament.safeDownCast(obj). This is equivalent to dynamic_cast<Blankevoort1991Ligament*>(obj) in C++.

◆ set_damping_coefficient()

void OpenSim::Blankevoort1991Ligament::set_damping_coefficient ( const double & value )

inline

Set the value of the damping_coefficient property.

◆ set_GeometryPath()

void OpenSim::Blankevoort1991Ligament::set_GeometryPath ( const GeometryPath & value )

inline

Set the value of the GeometryPath property.

◆ set_linear_stiffness()

void OpenSim::Blankevoort1991Ligament::set_linear_stiffness ( const double & value )

inline

Set the value of the linear_stiffness property.

◆ set_slack_length()

void OpenSim::Blankevoort1991Ligament::set_slack_length ( const double & value )

inline

Set the value of the slack_length property.

◆ set_transition_strain()

void OpenSim::Blankevoort1991Ligament::set_transition_strain ( const double & value )

inline

Set the value of the transition_strain property.

◆ setDampingCoefficientForceTimePerLength()

void OpenSim::Blankevoort1991Ligament::setDampingCoefficientForceTimePerLength ( double damping_coefficient )

Set the damping_coefficient property using a value in units of force*time/length (N*s/m).

Note that scaling the model keeps the damping_coefficient property (in units force*time/strain) constant, thus the damping_coefficient in units of force*time/length input to this function will be altered by scaling.

◆ setLinearStiffnessForcePerLength()

void OpenSim::Blankevoort1991Ligament::setLinearStiffnessForcePerLength ( double linear_stiffness )

Set the linear_stiffness property using a value in units of force/length (N/m).

Note that scaling the model keeps the linear_stiffness property (in units of force/strain) constant, thus the linear_stiffness in units of force/length input to this function will be altered by scaling.

◆ setSlackLengthFromReferenceForce()

void OpenSim::Blankevoort1991Ligament::setSlackLengthFromReferenceForce	(	double	force,
		const SimTK::State &	reference_state
	)

Set the slack_length property using the absolute spring force (N) in the ligament at a known pose (reference force).

Note that scaling the model will adjust the slack_length property, thus it is important to consider the order of scaling and using this function for your application.

◆ setSlackLengthFromReferenceStrain()

void OpenSim::Blankevoort1991Ligament::setSlackLengthFromReferenceStrain	(	double	strain,
		const SimTK::State &	reference_state
	)

Set the slack_length property using the strain in the ligament at a known pose (reference state).

Note that scaling the model will adjust the slack length property to hold the input reference strain constant if the input reference_state is equal to the default model pose (generated by initSystem()).

◆ upd_damping_coefficient()

double& OpenSim::Blankevoort1991Ligament::upd_damping_coefficient ( )

inline

Get a writable reference to the damping_coefficient property.

◆ upd_GeometryPath()

GeometryPath& OpenSim::Blankevoort1991Ligament::upd_GeometryPath ( )

inline

Get a writable reference to the GeometryPath property.

◆ upd_linear_stiffness()

double& OpenSim::Blankevoort1991Ligament::upd_linear_stiffness ( )

inline

Get a writable reference to the linear_stiffness property.

◆ upd_slack_length()

double& OpenSim::Blankevoort1991Ligament::upd_slack_length ( )

inline

Get a writable reference to the slack_length property.

◆ upd_transition_strain()

double& OpenSim::Blankevoort1991Ligament::upd_transition_strain ( )

inline

Get a writable reference to the transition_strain property.

OpenSim Property, Socket, Output, Input Documentation

◆ damping_coefficient

double OpenSim::Blankevoort1991Ligament::damping_coefficient

"The coefficient that multiplies the strain rate when computing the " " damping force. Units of N*s/strain. Default value of 0.003."

This property appears in XML files under the tag <damping_coefficient>. This property was generated with the OpenSim_DECLARE_PROPERTY macro; see Property to learn about the property system.

See also: get_damping_coefficient(), upd_damping_coefficient(), set_damping_coefficient()

◆ damping_force

double OpenSim::Blankevoort1991Ligament::damping_force

Provides the value of getDampingForce() and is available at stage SimTK::Stage::Velocity .

This output was generated with the OpenSim_DECLARE_OUTPUT macro.

◆ GeometryPath

GeometryPath OpenSim::Blankevoort1991Ligament::GeometryPath

"The set of points defining the path of the ligament"

This property appears in XML files under the tag <GeometryPath>. This property was generated with the OpenSim_DECLARE_UNNAMED_PROPERTY macro; see Property to learn about the property system.

See also: get_GeometryPath(), upd_GeometryPath(), set_GeometryPath()

◆ length

double OpenSim::Blankevoort1991Ligament::length

Provides the value of getLength() and is available at stage SimTK::Stage::Position .

This output was generated with the OpenSim_DECLARE_OUTPUT macro.

◆ lengthening_speed

double OpenSim::Blankevoort1991Ligament::lengthening_speed

Provides the value of getLengtheningSpeed() and is available at stage SimTK::Stage::Velocity .

This output was generated with the OpenSim_DECLARE_OUTPUT macro.

◆ linear_stiffness

double OpenSim::Blankevoort1991Ligament::linear_stiffness

"The slope of the linear region of the force-strain curve. " "Units of force/strain (N)."

This property appears in XML files under the tag <linear_stiffness>. This property was generated with the OpenSim_DECLARE_PROPERTY macro; see Property to learn about the property system.

See also: get_linear_stiffness(), upd_linear_stiffness(), set_linear_stiffness()

◆ slack_length

double OpenSim::Blankevoort1991Ligament::slack_length

"The length at which ligament begins developing tension. Units of m."

This property appears in XML files under the tag <slack_length>. This property was generated with the OpenSim_DECLARE_PROPERTY macro; see Property to learn about the property system.

See also: get_slack_length(), upd_slack_length(), set_slack_length()

◆ spring_force

double OpenSim::Blankevoort1991Ligament::spring_force

Provides the value of getSpringForce() and is available at stage SimTK::Stage::Position .

This output was generated with the OpenSim_DECLARE_OUTPUT macro.

◆ strain

double OpenSim::Blankevoort1991Ligament::strain

Provides the value of getStrain() and is available at stage SimTK::Stage::Position .

This output was generated with the OpenSim_DECLARE_OUTPUT macro.

◆ strain_rate

double OpenSim::Blankevoort1991Ligament::strain_rate

Provides the value of getStrainRate() and is available at stage SimTK::Stage::Velocity .

This output was generated with the OpenSim_DECLARE_OUTPUT macro.

◆ total_force

double OpenSim::Blankevoort1991Ligament::total_force

Provides the value of getTotalForce() and is available at stage SimTK::Stage::Velocity .

This output was generated with the OpenSim_DECLARE_OUTPUT macro.

◆ transition_strain

double OpenSim::Blankevoort1991Ligament::transition_strain

"The strain at which the ligament force-strain curve transitions from " "quadratic to linear. Units of strain. Default value of 0.06 (6%)."

This property appears in XML files under the tag <transition_strain>. This property was generated with the OpenSim_DECLARE_PROPERTY macro; see Property to learn about the property system.

See also: get_transition_strain(), upd_transition_strain(), set_transition_strain()

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

OpenSim/Simulation/Model/Blankevoort1991Ligament.h

OpenSim Properties, Sockets, Outputs, Inputs

Public Member Functions

Auto-generated functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ Blankevoort1991Ligament() [1/4]

◆ Blankevoort1991Ligament() [2/4]

◆ Blankevoort1991Ligament() [3/4]

◆ Blankevoort1991Ligament() [4/4]

Member Function Documentation

◆ calcDampingForce()

◆ calcInverseForceStrainCurve()

◆ calcSpringForce()

◆ calcTotalForce()

◆ clone()

◆ computeForce()

◆ computeMomentArm()

◆ computePotentialEnergy()

◆ extendAddToSystem()

◆ extendFinalizeFromProperties()

◆ extendPostScale()

◆ get_damping_coefficient()

◆ get_GeometryPath()

◆ get_linear_stiffness()

◆ get_slack_length()

◆ get_transition_strain()

◆ getClassName()

◆ getConcreteClassName()

◆ getDampingCoefficientForceTimePerLength()

◆ getDampingForce()

◆ getLength()

◆ getLengtheningSpeed()

◆ getLinearStiffnessForcePerLength()

◆ getRecordLabels()

◆ getRecordValues()

◆ getSpringForce()

◆ getStrain()

◆ getStrainRate()

◆ getTotalForce()

◆ getTransitionLength()

◆ safeDownCast()

◆ set_damping_coefficient()

◆ set_GeometryPath()

◆ set_linear_stiffness()

◆ set_slack_length()

◆ set_transition_strain()

◆ setDampingCoefficientForceTimePerLength()

◆ setLinearStiffnessForcePerLength()

◆ setSlackLengthFromReferenceForce()

◆ setSlackLengthFromReferenceStrain()

◆ upd_damping_coefficient()

◆ upd_GeometryPath()

◆ upd_linear_stiffness()

◆ upd_slack_length()

◆ upd_transition_strain()

OpenSim Property, Socket, Output, Input Documentation

◆ damping_coefficient

◆ damping_force

◆ GeometryPath

◆ length

◆ lengthening_speed

◆ linear_stiffness

◆ slack_length

◆ spring_force

◆ strain

◆ strain_rate

◆ total_force

◆ transition_strain