Mapdl.rpsd(ir='', ia='', ib='', itype='', datum='', name='', signif='', **kwargs)

Calculates response power spectral density (PSD).

APDL Command: RPSD


Arbitrary 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, ib

Reference numbers of the two variables to be operated on. If only one, leave IB blank.


Defines the type of response PSD to be calculated:

0,1 - Displacement (default).

2 - Velocity.

3 - Acceleration.


Defines the reference with respect to which response PSD is to be calculated:

1 - Absolute value.

2 - Relative to base (default).


Thirty-two character name identifying variable on listings and displays. Embedded blanks are compressed for output.


Combine 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).


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.