ABAQUS Volume II: I–Z - Manual (Page 23)

*IMPEDANCE
9.1 *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:
•
“Acoustic, shock, and coupled acoustic-structural analysis,” Section 6.9.1 of the ABAQUS Analysis
User’s Manual
•
“Acoustic loads,” Section 27.4.5 of the ABAQUS Analysis User’s Manual
•
*IMPEDANCE PROPERTY
•
*SIMPEDANCE
Required, mutually exclusive parameters:
PROPERTY
Set this parameter equal to the name of the *IMPEDANCE PROPERTY option defining the table
of impedance values to be used.
NONREFLECTING
Set NONREFLECTING=PLANAR (default) to specify the impedance corresponding to that of a
normal incidence plane wave.
Set NONREFLECTING=IMPROVED to specify the impedance corresponding to that of
a plane wave at an arbitrary angle of incidence. This parameter can be used only for transient
dynamics.
Set NONREFLECTING=CIRCULAR to specify a radiation condition appropriate for a
circular boundary in two dimensions or a right circular cylinder in three dimensions.
Set NONREFLECTING=SPHERICAL to specify a radiation condition appropriate for a
spherical boundary.
Set NONREFLECTING=ELLIPTICAL to specify a radiation condition appropriate for an
elliptical boundary in two dimensions or a right elliptical cylinder in three dimensions.
Set NONREFLECTING=PROLATE SPHEROIDAL to specify a radiation condition
appropriate for a prolate spheroidal boundary.
9.1–1
ABAQUS Version 6.1 Module: ID:
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