Home » Knowledge Base » NVH / Fatigue » BEM acoustics of a box with impedance condition
An example of a box shows how to set up an impedance condition. Collocation BEM with different boundary conditions is used Example 8.8 from LS-Dyna training class NVH, Fatigue and Frequency Domain Analysis with LS-DYNA by Yun Huang.
Keywords
*CONTROL_TERMINATION
*CONTROL_TIMESTEP
*DATABASE_BINARY_D3PLOT
*DEFINE_CURVE
*ELEMENT_SHELL
*END
*FREQUENCY_DOMAIN_ACOUSTIC_BEM
*KEYWORD
*MAT_RIGID
*NODE
*PART
*SECTION_SHELL
*SET_NODE
*SET_SEGMENT
*TITLE
*KEYWORD
*TITLE
Impedance example: 3D INT, UNIT CUBE
*FREQUENCY_DOMAIN_ACOUSTIC_BEM
1.21 343.0 5.45901 5.45901 1 0.005 0.0 20.e-6
0 0 1 1 0 0 1
3 1000 1.e-6 5 4
3
3 2 0 3 30
2 2 0 3 20 21
1 2 0 4 10 11
*CONTROL_TERMINATION
1.000000 0 0.000 0.000 0.000
*CONTROL_TIMESTEP
0.000 0.800000 0 0.000 0.000 0 0 0
0.000 0 0
*DATABASE_BINARY_D3PLOT
0.001000 0 0 0 0
0
*ELEMENT_SHELL
*NODE
*PART
cube
1 1 1 0 0 0 0 0
*SECTION_SHELL
1 2 0.000 0 0 0 0 0
0.100000 0.100000 0.100000 0.100000 0.000 0.000 0.000 0
*MAT_RIGID
1 0.100000 0.300000 0.000 0.000 0.000 0.000
1.000000 7 7
0.000 0.000 0.000 0.000 0.000 0.000
*DEFINE_CURVE
10
1. 415.03
10. 415.03
*DEFINE_CURVE
11
1. 0.
10. 0.
*DEFINE_CURVE
20
1. -1.
10. -1.
*DEFINE_CURVE
21
1. 0.
10. 0.
*DEFINE_CURVE
30
1. 0.
10. 0.
*SET_SEGMENT
*SET_NODE
1
100,101
*END
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