# PFMODE

I/O Options EntryUsed to request output of modal participation factors for all modal frequency response subcases.

## Format

PFMODE (type, FLUIDMP=fmp, STRUCTMP=smp, PANELMP=setp, FREQUENCY=setf, FILTER=fratio, NULL=ipower, RPCUTOFF=rval, RPDBACUT=rpdba, MTYPE=otype, CMSSET=seset, RTYPE=rtype, MODOUT=modoutID, modaloutfile, PEAKOUT) = setdof/PEAKOUT or option

## Examples

PFMODE(FLUID,STRUCTMP=30,FREQUENCY=391,PANELMP=ALL)=393
PFMODE(STRUCTURE,H3D)=23
PFMODE(FLUID,H3D,PEAKOUT)=11
PFMODE(STRUCTURE,H3D,PEAKOUT)=PEAKOUT
PFMODE(FLUID,PUNCH)=31

## Definitions

Argument Options Description
type <STRUCTURE, FLUID>
STRUCTURE (Default)
Requests output of structural modal participation factors.
FLUID
Requests output of acoustic modal participation factors.
fmp <ALL, N, NONE>
ALL
Participation factors will be computed for all calculated fluid modes.
N
Number of fluid modes for which modal participation factors will be computed, based on the largest magnitude of modal contribution.
NONE (Default)
Participation factors are not calculated for fluid modes.
smp <ALL, N, NONE>

Default =ALL (if type =STRUCTURE)

NONE (if type =FLUID)

ALL
Participation factors will be computed for all calculated structural modes.
N
Number of structural modes for which modal participation factors will be computed based on the largest magnitude of modal contribution.
NONE
Participation factors are not calculated for structural modes. 11
setp <ALL, NONE>
ALL
Output structural modal participation for each panel specified in the PANEL data.
NONE (Default)
Do not output panel modal participation.
setf <ALL, SID>
ALL (Default)
Participation factors are processed for all excitation frequencies.
SID
Participation factors are only processed for a set of excitation frequencies. SID refers to the ID of a SET of type FREQ.
fratio <REAL>

Default = 0.001

Specifies the value of a filter to be applied to the output. Values of modal participation below fratio times the magnitude of displacement or pressure are not output.
ipower <INTEGER>

Default = 30

When the magnitude of a modal participation is below 10 to the minus ipower, the modal participation will not be output. In other words, if the modal participation is less than 10-ipower, the participation output for this mode will be skipped.
rval <REAL>

Default = 0.0

The modal participation will be calculated at the excited frequencies when the magnitude of the response is above rval. The excitation frequency will be a subset of setf.
rpdba <Non-Negative REAL>

Default = 0.0

RPDBACUT is the decibel pressure cutoff value for fluid responses, and is similar to RPCUTOFF. It will take precedence over RPCUTOFF for fluid responses. A weighting is applied to RPDBACUT values at the excitation frequency. The modal participation will be calculated when the magnitude of the response is about the cutoff value. 8
otype <ALL, SYSTEM, CMS>

Default = SYSTEM

For SYSTEM, the output related to PFMODE will correspond to the whole model. Component modal participation will not be output by default. However, when using ALL or CMS, the component modal participation will be output. For the CMS option, there will not be system modal participation. Component modal participation can also be calculated for internal grids in the superelement.
seset <ALL, SID>

Default = ALL

Component modal participation of all the H3D superelements will be output by default. However, a specific set of superelement names for output can be specified.
rtype <DISP, VELO, ACCE> Structural modal participation will be output based on the specified option.
DISP (Default)
Displacement
VELO
Velocity
ACCE
Acceleration
modoutID Integer > 0

Default = blank

References a MODOUT Bulk Data Entry which identifies options for Displacement and Energy Eigenvectors from PFMODE. 13 14
modal <MODAL>

Default = blank

Modal Eigenvectors are output to the H3D file (MODAL). 12 14
outfile <PUNCH, H3D>

Default = H3D

Modal participation can be exported either into the H3D file or PUNCH file. Because of the large volume of data, it is recommended to export the modal participation data into a H3D file.
peakout If peakout is present inside the bracket of the PFMODE option, the filtered frequencies from the PEAKOUT card will be considered for the output of modal participation.
setdof/PEAKOUT <SID/PEAKOUT> Degrees-of-freedom for which the participation factors are to be processed. SID refers to the ID of a SET of type GRIDC for structure participation and GRID for fluid participation.
If PEAKOUT is specified instead of SID:
• Degrees-of-freedom for which the grid participation factors are to be processed will come from fluid DOFs in PEAKOUT Bulk Data.
Note: DOF are either structural or fluid DOFs, depending on the selection of type (STRUCTURE or FLUID).
• Filtered peak frequencies will be subcase dependent, if the multiple subcases are present.
• Filtered peak frequencies are only for either structural or fluid DOFs, depending on the selection of type (STRUCTURE or FLUID).
option <YES, ALL, NO, NONE, SID>

Default = ALL (if MODAL is specified) 12

YES, ALL, blank
Modal Eigenvectors are output for all grids.
NO, NONE
Modal Eigenvectors are not output.
SID
Modal Eigenvectors are output for the specified grid SET.

1. The output of both the PFMODE and PFPANEL must be either to an H3D file or to a PUNCH file. Both PFPANEL and PFMODE must have the same output option.
2. The modal participation output is sorted in descending order by magnitude of the modal participation in the PUNCH file output.
3. PFMODE(FLUID,..) and PFMODE(STRUCTURE,..) can coexist in the input data, but only one PFMODE(FLUID) and one PFMODE(STRUCTURE) are allowed in a single SUBCASE.
4. Keywords FLUIDMP and PANELMP are only valid if FLUID is specified.
5. If STRUCTURE is specified, setdof must reference a set of structural degrees-of-freedom. If FLUID is specified, setdof must reference a set of acoustic degrees-of-freedom.
6. The FREQUENCY keyword can be used to select a subset of excitation frequencies available.
7. The filter is applied to the magnitude of the modal participation factors. Only modal participation factors that pass the filter are output.
8. The dB value is calculated using $20{\mathrm{log}}_{10}\left(p/{p}_{0}\right)$ , where ${p}_{0}$ is the reference pressure. The reference pressure is dependent on the units specified on the UNITS input data. If the units are SI, the value is set as 2.0E-5 Pa. If they are CGS, it is set as 2.0E-4 barye. If they are MPa, it is set as 2.0E-11 MPa. If they are BG or EE, then it is set as 4.17E-7 lbf/ft2. If no UNITS data is present, the default value is 2.0E-11 MPa.
9. Legacy format for the export of modal participation to H3D or PUNCH files: PFMODE (type, OUTPUT=outfile)=setdof/PEAKOUT is also supported.
10. To output modal participation factors for interior points of a superelement (in a CMS model), the SEINTPNT entry can be used in the Subcase Information section to convert the interior points of interest to SID exterior points. After conversion, these points can now be referenced by the </PEAKOUT> option for the sedof/PEAKOUT argument.
11. smp=NONE is only effective for Fluid Modal Participation factor output (type=FLUID). Otherwise, it is interpreted as ALL for Structural Modal Participation output (type=STRUCTURE). For type=FLUID, smp and fmp can be set to NONE.
12. The “option” field is only valid when PFMODE(MODAL) is defined.
13. The MODOUT option is to output the results of eigenvectors that are calculated from the normal modes analysis in modal frequency response.

The MODOUT option is available to output the eigenvectors and the energy based on the eigenvectors of the same modal space associated with the corresponding modal participations output as part of the PFMODE entry. The modal space output via MODOUT respects the same filters and/or thresholds defined for the overall modal participation output on the PFMODE entry. For instance, if the number of modes for which the modal participations are calculated in the PFMODE entry is limited by say, STRUCTMP=5, then the same modal space containing the 5 modes is output for the Displacement and/or Energy eigenvectors requested via MODOUT.

In the example below, STRUCTMP=5 restricts the number of modes used for overall modal participation calculation to 5 (out a total number of 28 extracted modes).
PFMODE(STRUCTURE, STRUCTMP = 5,RTYPE = DISP, PUNCH, MODOUT=21) = 2
Therefore, you can see only 5 modes are used for modal participation output:
When the eigenvectors are requested using the MODOUT entry.
MODOUT     21   HD3
+        DISP   ALL
The same 5 modes being output in the H3D file for the MODOUT request.
14. The MODOUT and MODAL options cannot be defined simultaneously on a single PFMODE entry.