PFGRID
I/O Options EntryThe PFGRID command can be used in the I/O Options section to request output of acoustic grid participation factors for all Modal Frequency Response subcases. The output will be in the .h3d file.
Format
PFGRID (GRIDS=setg, GRIDF=setfl, SOLUTION=setf, NULL=ipower, RPCUTOFF=rval, RPDBACUT=rpdba, CONTOUR=YES/NO,PEAKOUT) = setdof/PEAKOUT
Examples
PFGRID(SOLUTION=391)=12
PFGRID(GRIDS=12,PEAKOUT)=23
PFGRID(GRIDF=34,PEAKOUT)=PEAKOUT
Definitions
Argument | Options | Description |
---|---|---|
setg | <ALL, NONE, SID> |
|
setfl | <ALL, NONE, SID> |
|
setf | <ALL, SID> |
|
ipower | <INTEGER> Default = 30 |
When the magnitude of a grid participation is below 10 to the minus ipower, the grid participation will not be output. Therefore, if the grid participation is less than 10-ipower, the result output for this grid will be skipped. |
rval | <REAL> Default = 0.0 |
The grid participation will be calculated at the excited frequencies when the magnitude of the pressure 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 grid participation will be calculated when the magnitude of the response is about the cutoff value. 4 |
CONTOUR | (YES/NO) |
|
peakout | If peakout is present as an option inside the parenthesis of the PFGRID data, the filtered frequencies from the PEAKOUT data will be considered for output of grid participation. | |
setdof/PEAKOUT | <SID/PEAKOUT> | Degrees-of-freedom for which the grid participation factors are to
be processed. SID refers to the ID of a SET of type
GRID. If PEAKOUT is specified instead of
SID:
|
Comments
- Output is to the H3D file only.
- Acoustic grid participation factors are available in a Coupled Frequency Response Analysis (Modal Frequency Response only).
- The SOLUTION keyword can be used to select a subset of excitation frequencies available.
- The dB value is calculated as , 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, it is set as 4.17E-7 lbf/ft2. If no UNITS data is present, the default value is 2.0E-11 MPa.