CORD1S

Bulk Data Entry

CORD1S – Spherical Coordinate System Definition, Form 1

Description

This entry defines a spherical coordinate system using three grid points. The first point is the origin, the second lies on the polar (Z) axis, and the third lies in the X-Z plane (see Figure 1).

Format

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

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

Field

Contents

CID

Unique coordinate system identification number.

(Integer > 0)

G1, G2, G3

Grid point identification number.

(Integer > 0; G1 ≠ G2 ≠ G3)

cord1s

Figure 1: Defining a Spherical Coordinate System (CID) using grid points G1, G2 and G3.

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 (see Guidelines for Bulk Data Entries for further information).

3.	The three points G1, G2, and G3 must be non-collinear. Non-collinearity is checked by the geometry processor.

4.	The location of a grid point (P in Figure 1) in this spherical coordinate system is given by (R, θ, and ). Where, θ and are measured in degrees.

5.	The displacement coordinate directions at P are dependent on the location of P (ur, uθ, and u) as shown in Figure 1. 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.	This card is represented as a system in HyperMesh.