#include <Cable.h>

Inheritance diagram for Cable:

Collaboration diagram for Cable:

Public Member Functions
	Cable (std::string simObjectName, ISimObjectCreator *creator)
	The constructor sets the pointer to the output object and the parser object.

	~Cable ()
	The destructor deletes dynamically allocated memory.

void	OdeFcn (const double dT, const double const adX, double const adXDot) const

void	InitialConditionSetup (const double dT, const double const adCurrentIC, double const adUpdatedIC, ISimObjectCreator *const creator)
	functionality for setting initialconditions based on input port results.

void	FinalSetup (const double dT, const double const adX, ISimObjectCreator const creator)

void	CalcOutput (const double dT, const double *const adX) const

bool	HasJacobians () const override

void	OdeJacobian (double T, const double X, double J, int nStates) override

int	GetJacobianSparsity (int nStates, int rowPtr, int colIdx) override

const double *	OutForceA (const double dT, const double *const adX)

const double *	OutForceB (const double dT, const double *const adX)

const double *	OutPosA (const double dT, const double *const adX)

const double *	OutPosB (const double dT, const double *const adX)

Protected Member Functions
void	UpdateLength (double newLength, double deltaT)

void	UpdateStiffness (const double const adForceA, const double const adForceB)
	Updates the stiffness of the cable to ensure that this is not too large.

void	UpdateInertia ()
	Updates the inertia of the cable according to the changing length.

Protected Attributes
ISignalPort *	m_inLength
	The cable length input port.

ISignalPort *	m_inVelA
	The velocity A input port.

ISignalPort *	m_inVelB
	The velocity B input port.

ISignalPort *	m_inPosA
	The position A input port.

ISignalPort *	m_inPosB
	The position B input port.

int	m_IStates
	The index to the internal states of the cable.

ICommonComputation *	m_commonCalc
	Calculations necessary for more than one output port.

int	m_numElements
	The number of elements to divide the cable into.

int	m_numNodes
	The number of nodes of the cable.

double	m_inertiaA
	The inertia of the end A.

double	m_inertiaB
	The inertia of the end B.

double	m_forceA [3]
	The force on the end A.

double	m_forceB [3]
	The force on the end B.

double *	m_lengths
	The lengths of the cable elements.

std::string	m_cableName
	The identification name of the cable;.

InternalCableWithBottomContact *	m_internalCable

SCableSpec	m_CableSpec
	The cable specification.

Detailed Description

This class simulates a cable object consisting of one or more elements. Each element is of type CableElDynStiff. Each element has methods to make it possible to use larger time steps in the integration. This is done by decreasing the stiffness of the element until the eigenfrequency of the element is low enough for the integration to be performed with the defined maximum step size.

Each element is regarded as a straight segment, responsible for calculating the forces acting on each of its ends, as well as the mass associated with each end node. The forces and mass from each element is added to the corresponding nodes of the cable, and the acceleration of each node is calculated in the OdeFcn.

The cable is influenced by:

Internal stiffness
Internal damping
Hydrodynamic normal and tangential forces
Buoyancy and gravity
Added mass

The calculation of these forces are more thoroughly explained in CableElDynStiff.

Properties

Property	Default	Comment
NumElements	2	The number of cable elements.
Length	100	Not used, as it is now read from an input port.
Density	-	The density of the cable (kg/m^3).
NumericalDamping	0	Added numerical damping on each node. The damping force is calculated as \(\vec F_i = -k m_i \vec v_i\), where \(\vec F_i\) is the added damping force, \(k\) is the numerical damping factor, \(m_i\) is the node inertia and \(\vec v_i\) is the velocity of the node.
Diameter	-	The diameter of the cable.
E	-	The Young's modulus (elasticity) of the cable.
DampingRatio	1	The relative axial damping of the cable. 0 is no damping, 1 is critical damping.
FluidRho	1025	The density of the ambient fluid.
MaxStepLength	0.01	Controls the stiffness of the cable to allow integration with step lengths up to this value.
MaxTension	-	The maximum tension. If above this value, the tension is set to this this value.
MaxAcceleration	1000	The maximum acceleration. If above this value, the acceleration is set to this this value.
StepSafetyFactor	50	A safety factor between the MaxStepLength and the one used for calculating the stiffness of the cable.
MeanTension	0	Possibility to add a mean tension to correct for decreased stiffness of the cable.
AdaptationPeriod	0	If above zero, this tells the cable to correct its initial length to avoid length errors because of decreased stiffness.
MaterialName	Trawl/Wire2	The material to use for visualizing the cable.
NumFaces	5	The number of planes to visualize the cable surface.
DrawScale	2	The scale of the visual appearance of the cable. This is used to make it more visible.

Input ports

Tag	Size	Comment
Length	1	The length of the cable.
PosA	3	The position of end A.
PosB	3	The position of end B.
VelA	3	The velocity of end A.
VelB	3	The velocity of end B.
VelWater	3	The velocity of the water.

Output ports

Tag	Size	Comment
ForceA	3	The force from end A of the cable.
ForceB	3	The force from end B of the cable.
PosA	3	The position of end A.
PosB	3	The position of end B.

Revision history:

24.07.2007 KJR: Initial version.
24.11.2010 KJR: Added some class documentation.

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

/update_root/webfhsim/reloadrepos/fhsim_marine_elements/src/cable/Cable.h

Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description