FREQ2

Bulk Data Entry

FREQ2 – Frequency List, Alternate Form 2

Description

Defines a set of frequencies to be used in the solution of frequency response problems by specification of a starting frequency, final frequency, and the number of logarithmic increments desired.

Format

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
FREQ2	SID	F1	F2	NF

Example

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
FREQ2	6	1.0	8.0	6

Field	Contents
SID	Identification number. No default (Integer > 0)
F1	First frequency in set. No default (Real > 0.0)
F2	Last frequency in set. No default (Real > 0.0, F2 > F1)
NF	Number of logarithmic intervals. Default = 1 (Integer > 0)

Comments

FREQ2 entries must be selected with the I/O Options or Subcase Information command FREQUENCY = SID.
The units for F1 and F2 are cycles per unit time.
The frequencies defined by this entry are given by $image\fiequalsf1.gif$
where $image\dequals.gif$ and i = 1, 2, …, (NF + 1).
All FREQi entries with the same set identification numbers will be used. Duplicate frequencies will be ignored. $image\f_sub_n.gif$ and $image\f_sub_n1.gif$ are considered duplicated if
$image\freq_eq.gif$
where DFREQ is a user parameter with a default of $image\10_neg_5.gif$ , and $image\fmin.gif$ are the maximum and minimum excitation frequencies of the combined FREQi entries.

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