GRID

Grid Point

Description: Defines the location of a geometric grid point, the directions of its displacement, and its permanent single-point constraints.

Format:

Example:

Field	Definition	Type	Default
ID	Grid point identification number.	Integer > 0	Required
CP	Identification number of coordinate system in which the location of the grid point is defined.	Integer ≥ 0 or blank	0
X1, X2, X3	Location of the grid point in coordinate system CP.	Real	Required
CD	Identification number of coordinate system in which the displacements, degrees of freedom, constraints, and solution vectors are all defined at the grid point.	Integer ≥ 0 or blank	0
PS	Permanent single-point constraints associated with grid point (any of the digits 1-6 with no imbedded blanks).	Integer ≥ 0 or blank
SEID	Superelement identification number.	Integer ≥ 0 or blank

Remarks:

1. All grid point identification numbers must be unique with respect to all other grid, scalar, and extra points.
2. The meaning of X1, X2 and X3 depend on the type of coordinate system, CP, as follows (see CORDi entry descriptions):

   Type	X1	X2	X3
   Rectangular	X	Y	Z
   Cylindrical	R	θ (degrees)	Z
   Spherical	R	θ (degrees)	ϕ (degrees)

3. The collection of all CD coordinate systems defined on all GRID entries is called the global coordinate system. All degrees of freedom, constraints, and solution vectors are expressed in the global coordinate system.
4. The SEID field can be overridden by use of the SESET entry.
5. A zero (or blank if the GRDSET entry is not specified) in the CP or CD fields refers to the basic coordinate system.