G.4.1 Global Coordinate System

The following coordinate systems are available for specification of the structure geometry.

Note: The following figures depict the global coordinates with Y as vertical. The coordinate systems follow the similar right-hand rule when Z is vertical. Refer to SET { Z | Y } UP for additional details.

Conventional Cartesian Coordinate System: This coordinate system is a rectangular coordinate system (X, Y, Z) which follows the orthogonal right hand rule. This coordinate system may be used to define the joint locations and loading directions.

Figure 1. Cartesian (Rectangular) Coordinate System
Cylindrical Coordinate System: In this coordinate system, the X and Y coordinates of the conventional Cartesian system are replaced by R (radius) and Ø (angle in degrees). The Z coordinate is identical to the Z coordinate of the Cartesian system and its positive direction is determined by the right hand rule.

Figure 2. Cylindrical Coordinate System
Reverse Cylindrical Coordinate System: This is a cylindrical type coordinate system where the R- Ø plane corresponds to the X-Z plane of the Cartesian system. The right hand rule is followed to determine the positive direction of the Y axis.

Figure 3. Reverse Cylindrical Coordinate System