Constraints: Define and assign constraints on nodes and additional node data
With this command constraints and additional node data are defined, that are saved within PATRAN interface as „Node Data“. For all nodes with no associations made the following defaults apply (within parentheses the related PATRAN variable is shown)
Node type (GTYP): G (structural nodes)
Number degrees of freedom (NDF): 6
Node class (CONFIG): 0
Coordinate system (CID): 0
Constraint flags (PSPC): 000000
With the NASTRAN interface, only the boundary condition flags and the local coordinate system are used, these values are stored optionally in the GRID records or in SPC1 records.
Different definitions are identified by a sequenced index. The values defined under such an index can be completely deleted and new defined. After saving a definition the index is increased by one. After entering an already defined index all associated values are shown within the dialog after pressing button “Show values” and can be deleted or plotted. Button „New index“ gives the next unique index. The constraints can be defined within a local coordinate system (for example radial components within a cylindrical coordinate system). The coordinate system must have been already defined.
Button „Apply“ saves the specified values for this definition. If there are already values stored under this index it will be asked for overwriting. Button „Delete“ deletes already saved values. Button „Plot“ plots boundary condition. The dialog remains active until it’s explicitly closed by „Cancel“.
Following Dialog shows the available options:
Node data (constraints)
Index: The index of a new or of an already saved definition must be given.
New index: Next available index is set.
Show values: The values of an already saved definition are displayed in the dialog.
Index2: The upper limit of a range of indices to be used by „Delete“ and „Plot“ can be given.
Node type: G, A, F, T for PATRAN interface.
# Degrees of freedom: The number of DOF for the nodes must be given.
Node class: Class ID for separating between node classes corresponding PATRAN interface can be given.
Boundary condition flags: A number consisting of the digits 1-6 must be given (for example the number 1346 stands for the flags 101101).
Local coordinate system
Local coordinate system: The option has to be set if the constraints are referring to a local coordinate system.
ID: The ID of an already defined coordinate system can be given (ID = 0 means global coordinate system). All currently defined coordinate systems are shown within the list box.
Node increment: If the constraints are defined for a local coordinate system which was defined using option „Boundary Curve“ in command Coordinate System the same increment as for the definition of the coordinate systems has to be given here.
The node selection must be given on which the boundary conditions should be applied.
Plot boundary conditions
Vector length: Max. length of plotted vectors must be given
Components 1-3 / 4-6: Select which components should be plotted. Translations (1-3) or rotations (4-6).
Superimpose: With this option set the previously used layer won’t be deleted prior to plotting, so it’s possible to do multiple plots using different colors.
Color: Give the color index to use for plotting the vectors.