Home » Knowledge Base » NVH / Fatigue » BEM acoustics of a simple car model
A simplified car model is subjected to SSD nodal force excitation. BEM acoustic analysis is coupled with SSD excitation via *FREQUENCY_DOMAIN_SSD. *FREQUENCY_DOMAIN_ACOUSTIC_FRINGE_PLOT_SPHERE is used to visualize noise distribution. Example 8.5 from LS-Dyna training class NVH, Fatigue and Frequency Domain Analysis with LS-DYNA by Yun Huang.
Keywords
*BOUNDARY_SPC_SET
*CONTROL_IMPLICIT_EIGENVALUE
*CONTROL_IMPLICIT_GENERAL
*CONTROL_IMPLICIT_SOLUTION
*DATABASE_BINARY_D3PLOT
*DATABASE_FREQUENCY_BINARY_D3SSD
*DATABASE_GLSTAT
*DEFINE_CURVE
*ELEMENT_SHELL
*END
*FREQUENCY_DOMAIN_ACOUSTIC_BEM
*FREQUENCY_DOMAIN_ACOUSTIC_FRINGE_PLOT_SPHERE
*FREQUENCY_DOMAIN_SSD
*KEYWORD
*MAT_ELASTIC
*NODE
*PART
*SECTION_SHELL
*SET_NODE_LIST
*SET_SEGMENT
*TITLE
*KEYWORD
*TITLE
A simple car model
*FREQUENCY_DOMAIN_SSD
1 100 1.000 0.000 0 0
0.020000 0 0 0.000 0.000
1 2 0
11 1 2 0 100 200 0 0
*DATABASE_FREQUENCY_BINARY_D3SSD
1
1.000000 101.00000 11
*FREQUENCY_DOMAIN_ACOUSTIC_BEM
1.210000 340.00000 1.000000 101.00000 11 0.001000 0.000 2.0000E-5
20000 0 0 0 4 0 0 0
2 1000 1.0000E-6 8 0.000 0.000 0 0
1
1 2 0 0
*FREQUENCY_DOMAIN_ACOUSTIC_FRINGE_PLOT_SPHERE
1 7. 13
*DATABASE_GLSTAT
0.002500 0 0 1
*DATABASE_BINARY_D3PLOT
1.000000 0 0 0 0
0
*BOUNDARY_SPC_SET
2 0 1 1 1
*CONTROL_IMPLICIT_EIGENVALUE
100 0.000 0 0.000 0 0.000 2 0.000
0 0 0 0
*CONTROL_IMPLICIT_GENERAL
1 0.000 0 0 0 0 0 0
*CONTROL_IMPLICIT_SOLUTION
1 0 0 0.000 0.000 0.000 0.000 0.000
2 1 0 2
0 0 0.000 1 2
*PART
A simple car model
2 2 2 0 0 0 0 0
*SECTION_SHELL
2 18 0.833000 3 3 0 0 0
0.010000 0.010000 0.010000 0.010000 0.000 0.000 0.000 0
*MAT_ELASTIC
2 7830.00002.0700E+11 0.300000 0.000 0.000 0
*DEFINE_CURVE
100 0 0.000 0.000 0.000 0.000 0
1.0000000 100.0000000
500.0000000 100.0000000
*DEFINE_CURVE
200 0 0.000 0.000 0.000 0.000 0
1.0000000 0.000
500.0000000 0.000
*SET_NODE_LIST
11 0.000 0.000 0.000 0.000MECH
700 701 706 707 11108 11111 11129 11130
11131 11132 11133 11134
*SET_NODE_LIST
2 0.000 0.000 0.000 0.000MECH
161 162 163 167 168 169 176 177
178 185 186 187 191 192 193 200
201 202 10296 10298 10299 10300 10301 10307
10309 10310 10311 10329 10332 10333 10334 10338
10341 10342 10358 10360 10361 10362 10363 10369
10371 10372 10373 10391 10394 10395 10396 10400
10403 10404 741 742 743 747 748 749
756 757 758 765 766 767 774 775
776 780 781 782 789 790 791 798
799 800 11232 11234 11235 11236 11237 11243
11245 11246 11247 11250 11252 11253 11254 11275
11278 11279 11280 11284 11287 11288 11290 11293
11294 11313 11315 11316 11317 11318 11324 11326
11327 11328 11331 11333 11334 11335 11356 11359
11360 11361 11365 11368 11369 11371 11374 11375
*SET_SEGMENT
*ELEMENT_SHELL
*NODE
*END
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