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An example of acoustic pressure scattered from a rigid spherical surface shows how to solve acoustiv scattering problems with *FREQUENCY_DOMAIN_ACOUSTIC_BEM and *FREQUENCY_DOMAIN_ACOUSTIC_INCIDENT_WAVE. Example 8.12 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
*DEFINE_PLANE
*ELEMENT_SHELL
*END
*FREQUENCY_DOMAIN_ACOUSTIC_BEM
*FREQUENCY_DOMAIN_ACOUSTIC_INCIDENT_WAVE
*KEYWORD
*MAT_RIGID
*NODE
*PART
*SECTION_SHELL
*SET_NODE_LIST
*TITLE

Reduced Input

*KEYWORD
*TITLE
Acoustic incident wave scattered from a sphere, and a reflecting plane.
*FREQUENCY_DOMAIN_ACOUSTIC_BEM
      1.21     340.0   100.000   500.000        21      0.00     0.000 2.000E-05
         1         1         0         0         4                   1
         3      1000 1.0000E-6         8
                   1
         1         1         0         3       100
*DEFINE_CURVE
       100         0  1.000000  1.000000     0.000     0.000         0
                10.0                 0.0
               500.0                 0.0
*FREQUENCY_DOMAIN_ACOUSTIC_INCIDENT_WAVE
         2       1.0       4.0         0         0
*DEFINE_PLANE
         1       1.0       0.0      -1.5       0.0       1.0      -1.5
       0.0       0.0      -1.5
*SET_NODE_LIST
         1     0.000     0.000     0.000     0.000
      2356      2357         0         0         0         0         0         0
*PART
control volume
         1         1         1         0         0         0         0         0
*SECTION_SHELL
         1         2
  0.010000  0.010000  0.010000  0.010000     0.000     0.000     0.000         0
*MAT_RIGID
         1  7.83E+03  2.07E+11  0.300000     0.000     0.000     0.000
  1.000000         7         7
     0.000     0.000     0.000     0.000     0.000     0.000
*DATABASE_BINARY_D3PLOT
 1.0000E-4         0         0         0         0
         0
*CONTROL_TERMINATION
 0.0010000         0     0.000     0.000     0.000
*CONTROL_TIMESTEP
     0.000  0.900000         0     0.000     0.000         0         0         0
     0.000         0         0                         0.000
*ELEMENT_SHELL
*NODE
*END

Figures

image_006.png

image01.png

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