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

#include <MPC.h>

Collaboration diagram for MPC:

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. More...

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

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

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. More...

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(), addMaster(), ASMs2DC1::addRigidCpl(), ASMs1DC1::addRigidCpl(), ASMs2D::constrainEdgeLocal(), ASMs3D::constrainFaceLocal(), ASMstruct::evalSolution(), 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:

src/Utility/MPC.h
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()