PROPERTY BOUNDARY CONSTRAINT [name] part dof

    

This command is used to apply fixed single point constraints in terms of translations and rotations. 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). For non-zero boundary conditions the command PROPERTY BOUNDARY PRESCRIBE should be used.

name = constraint name for use in future references.

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

dof = constrained degree 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.

2.

Degree of freedom releases
Degree of freedom releases may be defined by using degree of freedom $<0$or the command PROPERTY BOUNDARY RELEASE. All degrees of freedom are released with dof=0.

3.

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. For prescribed displacements use the command PROPERTY LOADS DISPLACE or PROPERTY BOUNDARY PRESCRIBE.

Examples:

1.

PROPERTY BOUNDARY CONSTRAINT P1 X

Constrain point P1 in X

2.

PROPERTY BOUNDARY CONSTRAINT L1 1456

Constrain line L1 in X translation and all rotations.ATT

3.

PROPERTY BOUNDARY CONSTRAINT L1 XSYMM

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

4.

PROPERTY BOUNDARY CONSTRAINT L1 -1

Release degree of freedom X on L1

See also the following commands

'CONSTRUCT COORDSYS'
'LABEL GEOMETRY CONSTRNT'
'LABEL MESH CONSTRNT'
'LABEL OPTIONS CONSTRNT'
'PROPERTY ATTACH'
'UTILITY DELETE CONSTRNT'
'UTILITY TABULATE PROPERTY CONSTRNT'