# CORD1S

Bulk Data Entry Defines a spherical coordinate system using three grid points. The first point is the origin, the second lies on the Z-axis, and the third lies in the X-Z plane.

## Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
CORD1S CID G1 G2 G3 CID G1 G2 G3

## Example

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
CORD1S 3 16 32 19

## Definitions

Field Contents SI Unit Example
CID Unique coordinate system identification.
Integer
Specifies an identification number for this coordinate system.
<String>
Specifies a user-defined string label for this coordinate system. 8

(Integer > 0 or <String>)

G1, G2, G3 Grid point identification numbers of points used to uniquely define the coordinate system.

(Integer > 0; G1G2G3)

## Comments

1. Coordinate system identification numbers on all CORD1C, CORD1R, CORD1S, CORD2C, CORD2R, CORD2S, CORD3R, and CORD4R entries must all be unique.
2. A duplicate identification number is allowed if the CID and GID are identical and the coordinates are within the value set by PARAM,DUPTOL.
3. The three points G1, G2, G3 must be non-collinear. Non-collinearity is checked by the geometry processor.
4. The location of a grid point (P) in this spherical coordinate system is given by (R, θ, and π). Where, θ and π are measured in degrees. See Figure 1.
5. The displacement coordinate directions at P are dependent on the location of P (Ur, Uθ, and Uz). The displacements in all three of these directions at the grid point are specified in units of length.
6. Points on the polar axis may not have their displacement directions defined in this coordinate system due to ambiguity. In this case, the defining rectangular system is used.
7. A maximum of two coordinate systems may be defined on a single entry.
8. String based labels allow for easier visual identification of coordinate systems, including when being referenced by other cards. Currently, coordinate systems with string IDs can be referenced only by JOINTG elements. For more details, refer to String Label Based Input File in the Bulk Data Input File.
9. This card is represented as a system in HyperMesh.