BEM acoustics with acoustic transfer vector II — Welcome to LS-DYNA Examples

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This example shows how to set up an modal acoustic transfer vector (MATV) computation with *FREQUENCY_DOMAIN_ACOUSTIC_BEM_MATV and how to run several loading cases on SSD with *CASE. Post-processing is done with *DATABASE_FREQUENCY_BINARY_D3SSD. Example 8.11 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
*CONTROL_TERMINATION
*DATABASE_BINARY_D3PLOT
*ELEMENT_SOLID
*END
*KEYWORD
*MAT_ELASTIC
*NODE
*PART
*SECTION_SOLID
*SET_NODE
*SET_NODE_LIST
*SET_SEGMENT


*END
*FREQUENCY_DOMAIN_ACOUSTIC_BEM_MATV
*INCLUDE
*KEYWORD


*CASE_BEGIN_1
*CASE_BEGIN_2
*CASE_BEGIN_3
*CASE_END_1
*CASE_END_2
*CASE_END_3
*DATABASE_FREQUENCY_BINARY_D3SSD
*DEFINE_CURVE
*DEFINE_CURVE_TITLE
*END
*FREQUENCY_DOMAIN_ACOUSTIC_BEM_MATV
*FREQUENCY_DOMAIN_SSD
*INCLUDE
*KEYWORD


Reduced Input

*KEYWORD
*CONTROL_IMPLICIT_GENERAL
         1     0.000         0         0         0         0         0         0
*CONTROL_IMPLICIT_EIGENVALUE
        20     0.000         0     0.000         0     0.000         0     0.000
         0         0         0         0
*CONTROL_IMPLICIT_SOLUTION
         1         0         0     0.000     0.000     0.000     0.000     0.000
         2         1         1         0         2         0
         0         0     0.000         1         2
*SET_NODE
         1
   2849000   2849001
*SET_NODE_LIST
         2
   2845697   2859262   2845667   2859094   2845637   2858926   2845607   2858758
   2845577   2858590   2845205   2858422   2845512   2858179   2845506   2858156
   2845507   2858170   2845509   2859349   2845715   2859400   2845708   2859315
   2845678   2859147   2845648   2858979   2845618   2858811   2845588   2858643
   2845558   2858475   2845464   2857919   2845458   2857901   2844797   2857771
   2845401   2857528   2845398   2857542   2845402   2857566   2845408   2857576
   2845407   2857552   2845404   2857592   2845412   2857602   2845411   2858172
   2845485   2858042   2845461   2857912   2844787   2857782   2845431   2857708
   2845430   2857698   2845429   2857724   2845434   2857731   2845433   2857715
   2845432   2857745   2845437   2857752   2845436   2857735   2845410   2857583
   2844895   2854145   2844894   2854122   2844888   2854098   2844885   2854074
   2844883   2854034   2844929   2854024   2844930   2854011   2844931   2856505
   2845184   2856265   2845183   2856246   2845190   2856286   2845189   2856270
   2845186   2856280   2845194   2856290   2845193   2856238   2845179   2855963
   2856337   2854202   2854207   2854200   2854429   2854426   2854450   2854447
   2854471   2854468   2854492   2854489   2854513   2854510   2854539   2854537
   2844961   2854526   2844956   2854355   2844915   2854376   2844919   2854383
   2844916   2854192   2844898   2854154   2844890   2854144         0         0
*BOUNDARY_SPC_SET
         2         0         1         1         1         1         1         1
*CONTROL_TERMINATION
  1.000000         0     0.000     0.000     0.000
*DATABASE_BINARY_D3PLOT
  0.005000         0         0         0         0
         0
*ELEMENT_SOLID
*NODE
*PART
engine_solids                                                                   
   2000657   2000657   2000657
*SECTION_SOLID
   2000657        18         0
*MAT_ELASTIC
   2000657 2.5400E+3 2.100E+11  0.300000     0.000     0.000         0
*SET_SEGMENT
*END


*KEYWORD
*INCLUDE
8.11.matv.engine.model.k
*FREQUENCY_DOMAIN_ACOUSTIC_BEM_MATV
$#      ro         c      fmin      fmax     nfreq    dt_out   t_start      pref
      1.21      340.     1000.     2000.         3                 0.0    20.e-6
$# nsidext   typeext   nsidint   typeint    fftwin     trslt    ipfile    iunits
         1         1         0         0         4
$#  method     maxit       res       ndd     tollr    tolfct     ibdim       npg
         2      1000     1.E-6         8
$#               nbc    restrt     iedge      noel     nfrup
                   1
$#    ssid    sstype      norm  bem_type       lc1       lc2
         1         2         1
*END


*KEYWORD
*INCLUDE
8.11.matv.engine.model.k
*FREQUENCY_DOMAIN_ACOUSTIC_BEM_MATV
      1.21      340.     1000.     2000.         3                 0.0    20.e-6
         1         1         0         0         4
         2      1000     1.E-6         8
                   1         1
         1         2         1
*CASE_BEGIN_1
*FREQUENCY_DOMAIN_SSD
         1        20     0.000     0.000         1         0
  0.020000         0         0     0.000     0.000
                                                           1         2         0
   2846004                   2         0       100
*DEFINE_CURVE
       100         0       1.0       1.0       0.0       0.0         0
               1000.               1000.
               3000.               1000.
*CASE_END_1
*CASE_BEGIN_2
*FREQUENCY_DOMAIN_SSD
         1        20     0.000     0.000         1         0
  0.020000         0         0     0.000     0.000
                                                           1         2         0
   2862261         0         2         0       200
*DEFINE_CURVE_TITLE
CurveGen_1
       200         0       1.0       1.0       0.0       0.0         0
               1000.               2000.
               3000.               2000.
*CASE_END_2
*CASE_BEGIN_3
*FREQUENCY_DOMAIN_SSD
         1        20     0.000     0.000         1         0
  0.020000         0         0     0.000     0.000
                                                           1         2         0
   2859766                   3         0       300
*DEFINE_CURVE_TITLE
CurveGen_1
       300         0       1.0       1.0       0.0       0.0         0
               1000.               1000.
               3000.               1000.
*CASE_END_3
*DATABASE_FREQUENCY_BINARY_D3SSD
         1
     1000.     2000.         3         0         0
*END

Figures

image_004.png

image_005.png

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