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

  1. FREQ2 entries must be selected with the I/O Options or Subcase Information command FREQUENCY = SID.
  2. The units for F1 and F2 are cycles per unit time.
  3. The frequencies defined by this entry are given by fi = F1*e(i-1)d

    where, d = 1 N F ln F 2 F 1 and i = 1, 2, ..., (NF + 1).

  4. 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
  5. This card is represented as a load collector in HyperMesh.