FREQ2

Bulk Data Entry 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

Definitions

Field	Contents	SI Unit Example
`SID`	Set 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 f_i = F1*e^(i-1)d
where, $d = \frac{1}{N F} ln \frac{F 2}{F 1}$ and i = 1, 2, ..., (NF + 1).
All FREQi entries with the same set identification numbers will be used. Duplicate frequencies will be ignored. $f_{N}$ and $f_{N - 1}$ are considered duplicated if:(1)
$| f_{N} - f_{N - 1} | < DFREQ * | f_{MAX} - f_{MIN} |$

Where,

DFREQ

User parameter with a default of 10^-5 * $f_{M A X}$

$f_{M I N}$

The maximum and minimum excitation frequencies of the combined FREQi entries
This card is represented as a load collector in HyperMesh.