PLAS, Lab,
LDSTEP, SUBSTEP,
FREQB, FREQE,
LogOpt, PlotType,
VAL1, VAL2,
VAL3, VAL4,
VAL5, VAL6
Plots a specified acoustic quantity during postprocessing of an acoustic
analysis.
LabThe acoustic quantity to calculate:
SIMP | — | Specific acoustic impedance on the selected surface. |
AIMP | — | Acoustic impedance on the selected surface. |
MIMP | — | Mechanical impedance on the selected surface. |
PRES | — | Average pressure on the selected surface. |
FORC | — | Force on the selected surface. |
POWE | — | Acoustic power on the selected surface. |
ERP | — | Equivalent radiated power on the selected structural surface (valid only for SHELL181, SOLID185, SOLID186, SOLID187, SOLSH190 and SHELL281). |
ERPL | — | Equivalent radiated power level on the selected structural surface (valid only for SHELL181, SOLID185, SOLID186, SOLID187, SOLSH190 and SHELL281). |
BSPL | — | Frequency-band sound pressure level on selected nodes. |
BSPA | — | A-weighted frequency-band sound pressure level on selected nodes. |
MENE | — | Acoustic potential energy on the selected elements. |
KENE | — | Acoustic kinetic energy on the selected elements. |
TENE | — | Acoustic total energy on the selected elements. |
PL2V | — | Average square of the L2 norm of pressure on the selected elements. |
LWIN | — | Input sound power level on defined port. |
LWOUT | — | Output sound power level on defined driven port. |
RL | — | Return loss on defined port. |
ALPHA | — | Absorption coefficient on defined port. |
TL | — | Transmission loss on defined ports. |
DFSTL | — | Transmission loss of random acoustic analysis. |
DFSPW | — | Radiated power in random acoustic analysis. |
LDSTEPSpecified load step. Defaults to the load step number specified on the
SET command, or defaults to 1 if SET has not been
issued. This default applies to all Lab values except DFSTL and DFSPW.
| — | Load step number. |
ALL | — | All load steps. |
AVG or 0 | — | Average result of multiple samplings in a random acoustic analysis (see the
MSOLVE command). This option is used only for
|
SUBSTEPSpecified substep. Defaults to the substep number specified on the SET
command, or defaults to ALL (all substeps at the specified load step) if
SET has not been issued. For Lab = BSPL or
BSPA, ALL is the only valid value.
| — | Substep number. |
ALL | — | All substeps. |
FREQBFrequency value representing one of the following:
Beginning frequency of the frequency range (FREQB to
FREQE) for the defined load step(s) and substeps
(SUBSTEP = ALL). If a SUBSTEP value
is specified, FREQB is invalid.
Central frequency of octave bands, used when LogOpt = OB1,
OB2, OB3, OB6, OB12, or OB24 and FREQE is blank.
FREQEEnding frequency of the frequency range (FREQB to
FREQE) for the defined load step(s) and sub-steps
(SUBSTEP = ALL). If blank, FREQE is set
to FREQB. If a SUBSTEP value is
specified, FREQE is invalid.
LogOptOctave bands:
OB0 | — | Narrow bands (default). |
OB1 | — | Octave bands. |
OB2 | — | 1/2 octave bands. |
OB3 | — | 1/3 octave bands. |
OB6 | — | 1/6 octave bands. |
OB12 | — | 1/12 octave bands. |
OB24 | — | 1/24 octave bands. |
PlotTypeType of plot:
LINE | — | Line plot (default). |
BAR | — | Bar pattern plot, used only for |
CONT | — | Waterfall diagram, used only for |
VAL1Input port number for Lab = LWIN, LWOUT, RL, ALPHA, or
TL.
VAL2Output port number for Lab = TL.
VAL3Reference power for Lab = LWIN, LWOUT, or EPRL (defaults to
1x10-12 W).
VAL4Fluid mass density for Lab = ERP or ERPL (defaults to 1.2041
kg/m3).
VAL5Speed of sound in the fluid for Lab = ERP or ERPL (defaults to
343.25 m/s).
VAL6Radiation efficiency for Lab = ERP or ERPL (defaults to
1).
The PLAS command plots the specified acoustic quantity on the selected exterior surface, the energy on selected elements, or the sound pressure level over frequency bands. The calculation is based on the pressure and velocity solution or the frequency-band sound pressure level (SPL).
The total pressure and velocity are used if the selected surface is the excitation source surface. To calculate the incoming and outgoing acoustic power and other sound power parameters on the input and output surfaces, issue the SF,,PORT command in the preprocessor to define port numbers.
The sound pressure level of the octave bands and general frequency band (defined via the HARFRQ command) is calculated at the selected nodes in the model.