ABAQUS Volume II: I–Z - Manual (Page 28)

*IMPEDANCE PROPERTY
Data lines to define an impedance using DATA=ADMITTANCE (default):
First line:
1. , the proportionality factor between pressure and displacement of the surface in the normal
direction. This quantity is the imaginary part of the complex admittance, divided by the angular
frequency; see “Acoustic loads,” Section 27.4.5 of the ABAQUS Analysis User’s Manual.
(Units of F
−1
L
3
.)
2. , the proportionality factor between pressure and velocity of the surface in the normal
direction. This quantity is the real part of the complex admittance. (Units of F
−1
L
3
T
−1
.)
3. Frequency. (Cycles/time.) Frequency dependence is active only during frequency domain
analysis in ABAQUS/Standard.
Repeat this data line as often as necessary in ABAQUS/Standard to describe the variation of the
coefficients with frequency. Only the first line entered will be used in direct-integration procedures.
Data lines to define an impedance using DATA=IMPEDANCE:
First line:
1. , the real part of the surface impedance. (Units of F L
−3
T.)
2. , the imaginary part of the surface impedance. (Units of F L
−3
T.)
3. Frequency. (Cycles/time.) Frequency dependence is active only during frequency domain
analysis in ABAQUS/Standard.
Repeat this data line as often as necessary in ABAQUS/Standard to describe the variation of the
coefficients with frequency. Only the first line entered will be used in direct-integration procedures.
9.2–2
ABAQUS Version 6.1 Module: ID:
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