ABAQUS Keywords Reference Manual  

*SIMPEDANCE
Define impedances of acoustic surfaces.

This option is used to provide surface impedance information or nonreflecting boundaries for acoustic and coupled acoustic-structural analysis.

Products: ABAQUS/Standard  ABAQUS/Explicit  

Type: History data

Level: Step  

References:

Optional parameters:

OP

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

Set OP=NEW if all existing surface impedances applied to the model should be removed. To remove only selected surface impedances, use OP=NEW and respecify all surface 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 the impedance on a surface forming an acoustic boundary: 

First line:

  1. Surface name.

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

Repeat this data line as often as necessary to define surface impedances over the model.