A class representing a general multi-point constraint equation. More...

#include <MPC.h>

Collaboration diagram for MPC:

[legend]

Classes
struct	DOF
	A struct representing one term in a multi-point constraint equation. More...

Public Member Functions
	MPC (int n, int d, Real s=Real(0))
	Constructor creating a constraint for a specified slave DOF.

void	addMaster (const DOF &dof, Real tol=Real(1.0e-8))
	Adds a master DOF to the constraint equation.

void	addMaster (int n, int d, Real c=Real(1), Real tol=Real(1.0e-8))
	Adds a master DOF to the constraint equation.

void	updateMaster (size_t pos, Real c)
	Updates the coefficient of the pos'th master DOF.

void	updateMaster (size_t pos, MPC *m)
	Updates the next chain element of the pos'th master DOF.

void	removeMaster (size_t pos)
	Removes the pos'th master DOF from the constraint equation.

bool	isChained () const
	Returns true if this MPC is chained.

bool	merge (const MPC *mpc)
	Merges the given MPC equation into this one.

int	renumberNodes (const std::map< int, int > &old2new, bool msg=false)
	Renumbers all node numbers in the constraint equation.

void	shiftNodes (int nshift)
	Increments node numbers in the constraint equation by nshift.

void	addOffset (Real offset)
	Increments the c0 coefficient by a given offset.

void	setSlaveCoeff (Real c0)
	Assigns a new c0 coefficient to the constraint equation.

const DOF &	getSlave () const
	Returns a reference to the slave DOF.

const DOF &	getMaster (size_t i) const
	Returns a reference to the i'th master DOF.

size_t	getNoMaster (bool recursive=false) const
	Returns the number of master DOFs.

Public Attributes
int	iceq
	Global constraint equation identifier.

Protected Member Functions
void	printMaster (std::ostream &os) const
	Prints out the master(s) of this constraint equation.

Private Attributes
DOF	slave
	The slave DOF of this constraint equation.

std::vector< DOF >	master
	The master DOFs of this constraint equation.

Friends
std::ostream &	operator<< (std::ostream &s, const MPC &mpc)
	Global stream operator printing a constraint equation.

Detailed Description

A class representing a general multi-point constraint equation.

A multi-point constraint (MPC) equation is used to introduce additional couplings between the degrees of freedom (DOF) in a FE grid.

An MPC equation is in general a linear coupling of one (slave) DOF to a set of master DOFs, and may be expressed as

\[ s = c_0 + c_1 m_1 + c_2 m_2 + \ldots + c_n m_n \]

where

\(s\) denotes the slave DOF
\(c_0\) is the value of the slave DOF when all master DOFs are zero, or when there are no masters in the equation (prescribed DOF).
\(m_i\) is a master DOF
\(c_i, i > 0\) is a constant scaling coefficient associated with the i'th master
n denotes the total number of master DOFs in the equation

When n = 0, the above equation represents a fixed ( \(c_0=0\)) or prescribed ( \(c_0\ne0\)) DOF.

One or more of the master DOFs may also be a slave in another constraint equation (chained constraints). In this case the two equations are combined during model preprocessing, to eliminate the master DOF that is constrained.

Constructor & Destructor Documentation

◆ MPC()

MPC::MPC	(	int	n,
		int	d,
		Real	s = `Real(0)`
	)

inline

Constructor creating a constraint for a specified slave DOF.

Parameters

[in]	n	The node number of the slave DOF (1...NNOD)
[in]	d	The local DOF number of the slave DOF (1...3)
[in]	s	Associated constrained value

The created constraint equation will by default constrain the specified slave DOF to zero. To constrain to a non-zero value, the method setSlaveCoeff() has to be invoked with the desired value.

References iceq.

Member Function Documentation

◆ addMaster() [1/2]

void MPC::addMaster	(	const DOF &	dof,
		Real	tol = `Real(1.0e-8)`
	)

Adds a master DOF to the constraint equation.

Parameters

[in]	dof	The the master DOF and associated coefficient to be added
[in]	tol	Tolerance for comparison with zero, if the coefficient c is zero, the master DOF is not added

References MPC::DOF::coeff, and master.

Referenced by ASMbase::add2PC(), ASMbase::add3PC(), ASMbase::addLocal2GlobalCpl(), addMaster(), ASMs2DC1::addRigidCpl(), ASMs1DC1::addRigidCpl(), ASMs2D::constrainEdgeLocal(), ASMs3D::constrainFaceLocal(), and merge().

◆ addMaster() [2/2]

void MPC::addMaster	(	int	n,
		int	d,
		Real	c = `Real(1)`,
		Real	tol = `Real(1.0e-8)`
	)

inline

Adds a master DOF to the constraint equation.

Parameters

[in]	n	The node number of the master DOF (1...NNOD)
[in]	d	The local DOF number of the master DOF (1...3)
[in]	c	The coefficient that this master should be scaled with
[in]	tol	Tolerance for comparison with zero

References addMaster().

◆ renumberNodes()

int MPC::renumberNodes	(	const std::map< int, int > &	old2new,
		bool	msg = `false`
	)

Renumbers all node numbers in the constraint equation.

Parameters

[in]	old2new	Old-to-new node number mapping
[in]	msg	If true, give error message for each invalid node number

Returns: Number of invalid node numbers detected

References master, MPC::DOF::node, utl::renumber(), and slave.

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

/home/runner/work/IFEM-2/IFEM-2/src/Utility/MPC.h
/home/runner/work/IFEM-2/IFEM-2/src/Utility/MPC.C

Classes

Public Member Functions

Public Attributes

Protected Member Functions

Private Attributes

Friends

Detailed Description

Constructor & Destructor Documentation

◆ MPC()

Member Function Documentation

◆ addMaster() [1/2]

◆ addMaster() [2/2]

◆ renumberNodes()