Define Coordinate Systems/Grids

Form: Coordinate/Grid Systems

Use the Advanced > Define > Coordinate System/Grids command to access the Coordinate/Grid Systems form. Alternatively, right click in a blank area of a display window showing an undeformed shape and select the Edit Grid Data command from the resulting pop-up menu to access the form. Use the Coordinate/Grid Systems form to (a) access other forms that can be used to add a new coordinate system and uniform grid, (b) convert a previously defined uniform (regular) grid system to a general (non-uniform) grid system, or (c) delete a previously defined coordinate/grid system.

Coordinate systems are defined by specifying their origins and orientations with respect to the fixed Global coordinate system. They are used to define the location and orientation of the associated grid system. Thus, coordinate systems are always defined as part of a coordinate/grid system pair. However, when only a coordinate system is needed, such as when viewing the model, defining the model (object local axes, loads, and the like), and reporting results, a coordinate/grid system can be defined with no grid lines.

A grid system is a set of intersecting lines used to aid in drawing the model. Grid systems may be Cartesian (rectangular), cylindrical, or general. Each grid system is defined with respect to its own coordinate system, so, as indicated previously, grid and coordinate systems are defined together as a single entity. An unlimited number of coordinate/grid systems can be defined, each with a unique name.

A regular system is any coordinate/grid system having a Cartesian (rectangular) or cylindrical grid system. A general system is a system comprised of arbitrarily defined grid lines. The Define Grid Data form can be used to define a regular system. To determine if a previously defined system is a regular or general system, access the Coordinate/Grid Systems form and highlight the system name in the Systems display area. If the Convert to General Grid check box is NOT checked (with the system name highlighted), the grid system is a regular system.

The Global coordinate system always exists, and has its own grid. All other systems are user defined with respect to the Global system.

Note:  Right clicking anywhere in an active window will display a drop-down menu of commands, including the Edit Grid Data command. Clicking that command will display the Coordinate/Grid Systems form.   

Use the following buttons and option on the Coordinate/Grid Systems form to define a new coordinate/grid system:

• Add New System button.

Define a regular system as follows:

• 1. Click the Add New System button to access the Coord System Location and Orientation form.

  2. Make any adjustment to the system location and orientation.

  3. Click the OK button to access the Define Grid System Data form; use that form to define the grid system.

Define a general system as follows:

• 1. Define a regular system using the Coord System Location and Orientation and Define Grid System Data forms as described above, except it is not necessary to define the grid system at this point.

  2. Click the OK button on the Define Grid Data form to redisplay the Coordinate/Grid Systems form and highlight the name of the new system in the Systems display list.

  3. Check the Convert to General Grid check box. The selected system will be instantly converted from a regular system (Cartesian or cylindrical)  to an equivalent general type.

• Add Copy of System button.

• 1. Click on a previously named system in the Systems display area to select it.

  2. Click the Add Copy of System button to access the Define Grid System Data form if a  regular system was highlighted or the Grid System Data form if a general system was highlighted; make any necessary modifications and click the OK button. CSiBridge will add a new coordinate/grid system that is identical to the selected system. The name of the system will be the same as the original system with a -1 added; for example, if the system being copied is CSYS1, the duplicate name will be CSYS1-1.

• Modify/Show System button.

• 1. Click on an existing Coordinate/Grid system to select it

  2. Click the Modify/Show System button to access the Define Grid System Data form (a regular system) or the Grid System Data form (a general system).

  3. Use the form to modify the grid system.

• Delete System button.

• 1. Click on a previously defined system in the Systems display area to select it.

  2. Click the Delete System button to delete the selected system.

Any coordinates defined with respect to the deleted system will be converted to global coordinates. If a system selected to be deleted is in use as part of some other definition in the model, it cannot be deleted.

• Convert to General Grid check box.

• Click on a system in the Systems display area to select it. If the Convert to General Grid check box is checked, the selected system is a general system (not Cartesian or cylindrical) and it cannot be changed to a regular system (Cartesian or cylindrical).

• If the Convert to General Grid check box is unchecked, the selected system is a regular system.

• Check the check box to instantly convert a selected uniform system to an equivalent general type system. After a system has been converted to a general system, it cannot be changed back to a uniform system. If the check box is checked by accident, click the Cancel button to exit the form without saving any changes.