To print out the characteristics of the orbits after a modal or harmonic analysis has been performed, use the PRORB command in /POST1. See Elliptical Orbit in this guide for a definition of the characteristics. Angles are in degrees and within the range of -180 through +180.

Because the elliptical orbit is valid only for nodes on the rotational velocity axis, the PRORB command is valid for current-technology beam and pipe elements. If you have a solid element model, you can add line elements (with negligible stiffness and mass) on the rotational velocity axis so that the orbit characteristics are calculated and printed out.

The following command string prints out the orbit characteristics at a given frequency:

/POST1
set,1,6		! read load step 1, substep 6
prorb		

The angles are expressed in degrees for the range of -180° to +180°. The position vector of the local Y axis in the global coordinate system is printed out along with the elliptical orbit characteristics.

To retrieve and store your orbit characteristics as parameters, use the *GET command with Item1 = ORBT after issuing the PRORB command.