PROPERTY BOUNDARY ELASTIC [name] part dof k

      

This command is used to define elastic supports (or non-zero single point constraints). 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 general non-zero boundary conditions the command PROPERTY BOUNDARY PRESCRIBE should be used.

name = property name for use in future references.

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

dof = 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

k spring constant.

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 $<0$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.

Examples:

1.

PROPERTY BOUNDARY ELASTIC P1 1 1.23

Apply an elastic support to point P1 acting in the x direction with spring constant 1.23.

2.

PROPERTY BOUNDARY ELASTIC SU7 Y 3.6E-4

Apply an elastic support to surface SU7 acting in the y direction with spring constant 3.6E-4.

See also the following commands

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