PROPERTY BOUNDARY EXTERNAL [name] part dof

      

This command is used to apply external degrees of freedom for use with super-elements. The degree of freedom names listed below are the defaults; these may be changed via the FEMGV resource file (see the Installation and Customisation Guide).

Nodes on a part can be defined to have their freedoms to be external to the model. This permits freedoms to be identified for connection to separate models in super-element or substructured analyses.

name = external freedom name for use in future references.

part = the name of a point, line, surface, body or set.

dof = external degrees of freedom.

1 or X = x-translation

2 or Y = y-translation

3 or Z = z-translation

4 or RX = x-rotation

5 or RY = y-rotation

6 or RZ = z-rotation

XSYMM = x-translation, y,z-rotations

YSYMM = y-translation, x,z-rotations

ZSYMM = z-translation, x,y-rotations

ALL = x,y,z-translations, x,y,z-rotations

XASYMM = x-rotation, y,z-translations

YASYMM = y-rotation, x,z-translations

ZASYMM = z-rotation, x,y-translations

ENCASTRE = x,y,z-translations, x,y,z-rotations

PINNED = x,y,z-translations

NOROTATE = x,y,z-rotations

Notes:

1.

Degree of freedom indicator
The degree of freedom may be input as text or an integer. More than one degree of freedom may be referenced at any time. In integer syntax any integer which is a combination of at most five of the digits 1-6 is a valid constraint. In text format a list of degree of freedom names may be entered delimited by spaces or a degree of freedom macro (e.g. XSYMM) may be entered. Degree of freedom releases may be defined by using degree of freedom $<0$.All degrees of freedom are released with dof=0.

2.

Interaction with local coordinate systems
All nodes lying on the specified `part' of the structure will have the degrees of freedom `dof' constrained. If a node lies on several constrained parts, the constraints will be added. To get skew boundary conditions, a local coordinate system has to be attached to the part using the commands CONSTRUCT COORDSYS, and PROPERTY ATTACH.

Examples:

1.

PROPERTY BOUNDARY EXTERNAL P1 X

Constrain point P1 in X

2.

PROPERTY BOUNDARY EXTERNAL L1 1456

Constrain line L1 in X translation and all rotations.

3.

PROPERTY BOUNDARY EXTERNAL L1 XSYMM

Constrain line L1 in X translation and rotations Y and Z.

4.

PROPERTY BOUNDARY EXTERNAL L1 -1

Release degree of freedom X on L1

See also the following commands

'LABEL GEOMETRY EXTERNAL'
'LABEL MESH EXTERNAL'
'LABEL OPTIONS CONSTRNT'
'UTILITY DELETE CONSTRNT'
'UTILITY TABULATE PROPERTY CONSTRNT'