PFMODE
I/O Options and Subcase Information Entry The PFMODE command can be used in the I/O Options section 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> |
|
fmp | <ALL, N, NONE> |
|
smp | <ALL, N,
NONE> Default =ALL (if type =STRUCTURE) NONE (if type =FLUID) |
|
setp | <ALL, NONE> |
|
setf | <ALL, SID> |
|
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 result 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. 9 |
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.
|
modoutID | Integer > 0 Default = blank |
References a MODOUT Bulk Data Entry which identifies options for Displacement and Energy output based on Eigenvectors from PFMODE. |
modal | <MODAL> Default = blank |
Modal Eigenvectors are output to the H3D file (MODAL). |
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:
|
option | <YES, ALL,
NO, NONE,
SID> Default = ALL (if MODAL is specified) 13 |
|
Comments
- 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.
- The modal participation output is sorted in descending order by magnitude of the modal participation in the PUNCH file output.
- 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.
- Keywords FLUIDMP and PANELMP are only valid if FLUID is specified.
- 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.
- The FREQUENCY keyword can be used to select a subset of excitation frequencies available.
- The filter is applied to the magnitude of the modal participation factors. Only modal participation factors that pass the filter are output.
- If the magnitude of the total response at a selected response degree-of-freedom is less than 10-ipower, then no modal participation factors are processed. If ipower is not in the range of 1 to 31, the default of 30 is used.
- The dB value is calculated using , where 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.
- Legacy format for the export of modal participation to H3D or PUNCH files: PFMODE (type, OUTPUT=outfile)=setdof/PEAKOUT is also supported.
- 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 eSIDxterior points. After conversion, these points can now be referenced by the </PEAKOUT> option for the sedof/PEAKOUT argument.
- 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.
- The “option” field is only valid when PFMODE(MODAL) is defined.