harfrq

Mapdl.harfrq(freqb='', freqe='', logopt='', freqarr='', toler='', **kwargs)

Defines the frequency range in a harmonic analysis.

APDL Command: HARFRQ

Parameters
  • freqb – Frequency (Hz) at the beginning of the FREQB to FREQE range (if FREQE > FREQB). If FREQE is blank, the solution is done only at frequency FREQB (the central frequency of octave bands, when LogOpt = OB1, OB2, OB3, OB6, OB12 or OB24).

  • freqe – Frequency at end of this range. Solutions are done at an interval of (FREQE-FREQB) / NSBSTP, ending at FREQE. No solution is done at the beginning of the frequency range. NSBSTP is input via the NSUBST command. See the EXPSOL command documentation for expansion pass solutions.

  • -- – Reserved.

  • logopt

    Logarithm frequency span. Solutions are done at an interval of (log(FREQE) - log(FREQB)) / (NSBSTP-1), (NSBSTP>1). The central frequency or beginning frequency is used for NSBSTP = 1. Valid values are:

    OB1 - Octave band.

    OB2 - 1/2 octave band.

    OB3 - 1/3 octave band.

    OB6 - 1/6 octave band.

    OB12 - 1/12 octave band.

    OB24 - 1/24 octave band.

    LOG - General logarithm frequency span.

  • freqarr – An array containing frequency values (Hz). Combined with the tolerance argument, Toler, these values are merged with values calculated based on the specifications from FREQB, FREQE, and LogOpt, as well NSBSTP on the NSUBST command and Clust on the HROUT command. Enclose the array name in percent (%) signs (for example, HARFRQ,,,,,%arrname%). Use *DIM to define the array.

  • toler – Tolerance to determine if a user input frequency value in FREQARR is a duplicate and can be ignored. Two frequency values are considered duplicates if their difference is less than the frequency range multiplied by the tolerance. The default value is 1 x 10-5.

Notes

Defines the frequency range for loads in the harmonic analysis (ANTYPE,HARMIC).

Do not use this command for a harmonic ocean wave analysis (HROCEAN).

When frequencies are user-defined, the array FREQARR must be one- dimensional and contain positive values. User-defined frequency input is not supported in the following cases:

in a cyclic symmetry harmonic analysis

when the Variational Technology method is used (Method = VT on the HROPT command)

This command is also valid in PREP7.