HARFRQ, FREQB
, FREQE
, --, LogOpt
, FREQARR
, Toler
Defines the frequency range in a harmonic analysis.
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.
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:
when the Variational Technology method is used (Method
= VT on the HROPT command)
This command is also valid in PREP7.