b2000::DegreesOfFreedom Class Reference

#include "b2degrees_of_freedom.H"

Inheritance diagram for b2000::DegreesOfFreedom:

Collaboration diagram for b2000::DegreesOfFreedom:

Public Member Functions
virtual int	get_number_of_dof () const
virtual size_t	set_global_dof_numbering (size_t index)
virtual std::pair< size_t, size_t >	get_global_dof_numbering () const
Public Member Functions inherited from b2000::Object
virtual const std::string &	get_object_name () const
virtual	~Object ()

Additional Inherited Members
Static Public Attributes inherited from b2000::Object
static ObjectType	type

Detailed Description

Abstract class defining an interface for entities containing degrees-of-freedom (dof's). The purpose is to establish a numbering scheme for all dof's present in a Finite Element model. Derived classes need to override only the pure virtual functions.

Entities containing degrees-of-freedom are typically Node and Element instances. Node instances define e.g. displacement and/or rotation degrees-of-freedom, while Element instances may define element-internal degrees-of-freedom, such as incompatible modes.

The degrees-of-freedom belonging to an entity are sequentially arranged in the global solution vector: If the number of dof's of an entity is n, and i is the index into the global solution vector for the first dof, then the global numbering is [i, i + 1, i + 2, ..., i + (n - 1)]. The start index for the next entity is j = i + n, thus, the global numbering for the next entity is [j, j + 1, ..., j + (m - 1)], with m being the number of dof's of the next entity.

This numbering scheme applies not only to the global solution vector, but to any global vectorial and tensorial quantities (e.g. global vector of internal forces, global stiffness matrix, global constraint equations, etc.).

Member Function Documentation

get_global_dof_numbering()

virtual std::pair< size_t, size_t > b2000::DegreesOfFreedom::get_global_dof_numbering ( ) const

inlinevirtual

Returns

A pair (i, i+n), with i being the global number of the first dof of the entity, and n equal to get_number_of_dof().

Example

std::pair<size_t, size_t>
get_global_dof_numbering() const {
    return std::pair<size_t, size_t>(
        internal_dof_index, internal_dof_index + 4);
}

The variable internal_dof_index is a member of the element class and was set in set_global_dof_numbering().

Reimplemented in b2000::SuperElement< T, MATRIX_TYPE >, b2000::ElementCFDHeat2DFieldL2Constant< FLUX, AXISYMMETRIC >, and b2000::Element.

get_number_of_dof()

virtual int b2000::DegreesOfFreedom::get_number_of_dof ( ) const

inlinevirtual

Returns

The number of degrees-of-freedom of the entity. Entities with no degrees-of-freedom should return 0.

Example

A Finite Element with 4 internal dof's would return 4.

Reimplemented in b2000::SuperElement< T, MATRIX_TYPE >, b2000::ElementCFDHeat2DFieldL2Constant< FLUX, AXISYMMETRIC >, and b2000::Element.

set_global_dof_numbering()

virtual size_t b2000::DegreesOfFreedom::set_global_dof_numbering ( size_t  index )

inlinevirtual

Set the global degree-of-freedom numbers of the degrees-of-freedom belonging to the entity.

Parameters

index

The index into the global solution vector of the first degree-of-freedom of the entity.

Returns

The index into the global solution vector past the last degree-of-freedom of the entity.

Example

A Finite Element with 4 internal dof's:

size_t
set_global_dof_numbering(size_t index) {
    internal_dof_index = index;
    return index + 4;
}

The variable internal_dof_index is a member of the element class.

Reimplemented in b2000::SuperElement< T, MATRIX_TYPE >, b2000::ElementCFDHeat2DFieldL2Constant< FLUX, AXISYMMETRIC >, and b2000::Element.

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

• model/b2degrees_of_freedom.H