PRMC

PRMC, LSTEP, SBSTEP, TIMFRQ, KIMG, HIbeg, HIend, Matrix
Prints the modal coordinates from a mode-superposition solution.

POST1: Special Purpose

LSTEP, SBSTEP

Print the solution identified as load step LSTEP and substep SBSTEP.

TIMFRQ

As an alternative to LSTEP and SBSTEP, print the solution at the time value TIMFRQ (for ANTYPE,TRANS) or frequency value TIMFRQ (for ANTYPE,HARMIC). LSTEP and SBSTEP should be left blank.

KIMG

Key for printing real or imaginary solution. Valid only for ANTYPE,HARMIC.

0 (or blank)	—	Print the real solution (default).
1	—	Print the imaginary solution.
2	—	Print the amplitude.

HIbeg, HIend

For cyclic symmetry solutions, print the solutions in the harmonic index solution range HIbeg to HIend. Defaults to all harmonic indices (all modes).

Matrix

Create an APDL Math dense matrix with the name entered on this field (up to 32 characters; for nomenclature guidelines see Guidelines for Parameter Names in the Ansys Parametric Design Language Guide). The matrix contains the modal coordinates. By default (Matrix = blank), no APDL Math matrix is created.

Notes

PRMC prints the modal coordinates (the factors which modes may be multiplied by to obtain their contribution to the response) at a certain time point (transient analyses) or frequency point (harmonic analyses).

The printout contains four columns: the mode number (labelled MODE), the modal frequency (labelled FREQ), the modal coordinate or mode multiplier (labelled MULT), and the normalized modal coordinate (labelled NORM). The normalized modal coordinate is the ratio of absolute value of the mode multiplier divided by the sum of the absolute values of all multipliers listed (at a solution time/frequency and harmonic index). It may be useful for identifying the dominant modes. Maximum values of each column are also listed at the end of each report.

By default, the real part of the modal coordinate values are printed even if the modal coordinates are complex.

When Matrix is specified, an APDL Math dense matrix similar to the one created with the *DMAT command is created. If PRMC is issued multiple times with the same name entered on Matrix or if a matrix with the specified name already exists, the matrix is overwritten. This matrix contains four to five columns depending on the analysis. The first four columns are the ones printed by PRMC. The fifth column contains the harmonic index for cyclic analysis only. This matrix can then be used in APDL Math data processing and file handling (See APDL Math in the Ansys Parametric Design Language Guide). For instance, *EXPORT can be issued to export the PRMC data to a .csv file.

For transient analyses, a .rdsp file must be available. For harmonic analyses, a .rfrq file must be available. The content of these files depends on the OUTRES command settings. Note that the default for mode-superposition transient analysis is to write the reduced displacement file every 4th substep. For more information, see Command Default in the OUTRES command description.

For a cyclic harmonic mode-superposition analysis, use the CYCFILES command to identify the .rfrq and modal .rst files. For other analyses, use the FILE command to specify the .rdsp or .rfrq file.

This information can also be obtained from the optional Jobname.mcf text file (see the TRNOPT and HROPT commands), and it can be plotted using the PLMC command. For more information on modal coordinates, see Mode-Superposition Method in the Mechanical APDL Theory Reference

Example Usage

/POST1
FILE,,rdsp                     ! Specify Jobname.rdsp file from a previous MSUP transient analysis
! Print modal coordinates from the second loadstep and fourth substep  
PRMC,2,4,,,,,MAT               ! also create an APDL Math matrix called MAT  
*EXPORT,MAT,CSV,PRMCFILE.CSV   ! Export MAT to a .csv file

Menu Paths

This command cannot be accessed from a menu.