Expansion in this case refers to expansion of the cyclic sectors, but also includes what stages to visualize. The expansion closely follows the behavior of the EXPAND command. The nodes and elements of the base sector are expanded to other sectors of interest, resulting in a larger database. Note that postprocessing of the expanded system is limited to the session in which the expansion was initiated. While it is possible to save and resume an expanded database, postprocessing that resumed database in conjunction with the original results file used to create it is not possible.
The initial expansion is done by issuing the MSOPT,EXPA command one or more times followed by the SET commands. Many specification combinations are allowed, ranging from enabling expansion of all stages to choosing specific stages and sectors to expand. For more details, refer to the MSOPT command. Additions can be made to the desired expansion, or it can be reset. The SET command expands the database and results. SET,,,,AMPL is not supported for expanded results. To compute the amplitude of a single complex mode that was calculated in a modal analysis using the damped eigensolver (MODOPT, DAMP), issue the MAXCYCMODE command.
Note: All nodes and elements of a specified stage and sector to be expanded are automatically selected after expansion regardless of selection status prior to the expansion.
For multiharmonic analyses with one or more stage clones, it is possible to
achieve the entire physical stage expansion by issuing MSOPT,EXPA,ALL, which expands all stages and accumulates the results for
the multiharmonic stage clones. It may be of interest to see the contribution of one
or more harmonics of a stage that does not represent the total accumulated results
of all harmonics included in the analysis. To look at the contribution of a
single stage clone, you can use MSOPT,EXPA,StageCloneName. Any additional stage clones added will
be accumulated. See the following table for some example commands issued using
MSOPT with descriptions of their results.
Table 6.1: Example Usage of MSOPT Command to Expand Stages
| Command | Description |
| MSOPT,EXPA,ALL | Expands all stages including clones and accumulates the entire available result |
MSOPT,EXPA,StageClone1Name | Expands only StageClone1 to see its contribution to the overall result |
MSOPT,EXPA,StageClone1NameMSOPT,EXPA, | Expands StageClone1 and StageClone3 and outputs the accumulation of only those two harmonics |
| MSOPT,EXPA,0 | Resets all expansion settings. |
After the initial expansion, stages and sectors can be added to the expansion using the MSOPT command. Additionally, it is possible to reset entire stages or the entire system using the MSOPT command.
Some cases may require resetting the database back to the model that was solved. This can be accomplished by exiting the /POST1 processor and issuing the FINI command, which resumes the solved database and eliminates the expanded database.
For stages solved using multiple harmonics, you must explicitly expand the original stage and each desired harmonic stage clone using MSOPT,EXPA. Any harmonic stage clones that have not been expanded will not be added into the final result.