ABAQUS Keywords Reference Manual  


9. I

*IMPEDANCE
Define impedances for acoustic analysis.

This option is used to provide boundary impedances or nonreflecting boundaries for acoustic and coupled acoustic-structural analyses.

Products: ABAQUS/Standard  ABAQUS/Explicit  

Type: History data

Level: Step  

References:

Optional parameters:

OP

Set OP=MOD (default) to modify existing impedances or to define additional impedances.

Set OP=NEW if all existing impedances applied to the model should be removed. To remove only selected impedances, use OP=NEW and respecify all impedances that are to be retained.

IMPROVED PLANE

Include this parameter if the improved plane wave radiation condition is used.

This parameter can be used only for transient dynamics.

Data lines to define an impedance: 

First line:

  1. Element number or element set label.

  2. Surface impedance type label, In, for impedance on face n.

  3. Name used in the *IMPEDANCE PROPERTY option that defines the coefficients to be used for this impedance. Leave this field blank to specify the default plane wave absorbing boundary condition.

Repeat this data line as often as necessary to define impedances.