PACABS

Bulk Data Entry Defines the properties of an acoustic absorber element.

Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
PACABS PID SYNTH TID1 TID2 TID3   CUTFR B  
    K M            

Example

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
PACABS 3   2 3 5   400.0    

Definitions

Field Contents SI Unit Example
PID Property identification number.

No default (Integer > 0)

  
SYNTH Controls the calculation of the B, K, and M values.
YES (Default)
The B, K, and M values are calculated from TIDi tables.
NO
The B, K, and M values are used directly from the B, K, and M fields.

(Character)

  
TID1 Identification number of a TABLEDi entry that defines the resistance. 2

Default = blank (Integer > 0)

  
TID2 Identification number of a TABLEDi entry that defines the reactance. 2

Default = blank (Integer > 0)

  
TID3 Identification number of a TABLEDi entry that defines the weighting function. 2

Default = blank (Integer > 0)

  
CUTFR Cutoff frequency for tables referenced above.

(Real > 0.0)

  
B Equivalent Damping per unit area.

Default = blank (Real ≥ 0.0)

  
K Equivalent Stiffness per unit area.

Default = blank (Real ≥ 0.0)

  
M Equivalent Mass per unit area.

Default = blank (Real ≥ 0.0)

  

Comments

  1. The PACABS Bulk Data Entry should only be referenced by a CHACAB Bulk Data Entry.
  2. TID1 and TID2 should be specified (TID3 is not mandatory), if SYNTH field is set to YES. The equivalent structural model will be derived from TIDi. If TID3 is blank, then the weighting function is set to 1.0.
  3. The TIDi tabular data should be defined as a function of frequency in cycles/unit time.
  4. If SYNTH=NO, then B, K, or M fields will be used to derive the Equivalent Structural Model.