RPSD, IR, IA, IB, ITYPE, DATUM, Name, --, SIGNIF
Calculates response power spectral density (PSD).
IRArbitrary reference number assigned to the resulting
variable (2 to NV [NUMVAR]). If this number is the same as for a previous variable, the previous
variable will be overwritten with this result.
IA, IBReference numbers of the two variables to be operated
on. If only one, leave IB blank.
ITYPEDefines the type of response PSD to be calculated:
0,1 | — | Displacement (default). |
2 | — | Velocity. |
3 | — | Acceleration. |
DATUMDefines the reference with respect to which response PSD is to be calculated:
1 | — | Absolute value. |
2 | — | Relative to base (default). |
NameThirty-two character name identifying variable on listings and displays. Embedded blanks are compressed for output.
SIGNIFCombine only those modes whose significance level
exceeds the SIGNIF threshold. The significance
level is defined as the modal covariance matrix term divided by the
maximum of all the modal covariance matrix terms. Any term whose significance
level is less than SIGNIF is considered
insignificant and does not contribute to the response. All modes are
taken into account by default (SIGNIF =
0.0).
The significance level definition is identical
to the one used for the combination (SIGNIF on the PSDCOM command); however, the default
value is different.
The significance does not apply to spatial correlation (PSDSPL) and wave propagation (PSDWAV) response power spectral density.
This command calculates response power spectral density (PSD)
for the variables referenced by the reference numbers IA and IB. The variable
referred by IR will contain the response
PSD. You must issue the STORE,PSD command first; File.PSD must be available for the calculations to occur.
See POST26 - Response Power Spectral Density in the Mechanical APDL Theory Reference for more information on these equations.