SSD with base and enforced motion
This sequence of two examples shows how to set up an input file for large mass method. In the first file a rectangular plate is computed with base acceleration using *FREQUENCY_DOMAIN_SSD. In the second file for the same structure large mass method is applied with keywords *CONTROL_FREQUENCY_DOMAIN, *ELEMENT_MASS_NODE_SET and *BOUNDARY_SPC. Example 5.2 from LS-Dyna training class NVH, Fatigue and Frequency Domain Analysis with LS-DYNA by Yun Huang.
https://www.dynaexamples.com/nvh/example-05-02
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SSD with base and enforced motion
This sequence of two examples shows how to set up an input file for large mass method. In the first file a rectangular plate is computed with base acceleration using *FREQUENCY_DOMAIN_SSD. In the second file for the same structure large mass method is applied with keywords *CONTROL_FREQUENCY_DOMAIN, *ELEMENT_MASS_NODE_SET and *BOUNDARY_SPC. Example 5.2 from LS-Dyna training class NVH, Fatigue and Frequency Domain Analysis with LS-DYNA by Yun Huang.
*BOUNDARY_SPC_SET
*CONTROL_IMPLICIT_EIGENVALUE
*CONTROL_IMPLICIT_GENERAL
*CONTROL_IMPLICIT_SOLUTION
*DATABASE_FREQUENCY_ASCII_NODOUT_SSD
*DATABASE_FREQUENCY_BINARY_D3SSD
*DATABASE_HISTORY_NODE_SET
*DATABASE_NODAL_FORCE_GROUP
*DEFINE_CURVE
*ELEMENT_SHELL
*END
*FREQUENCY_DOMAIN_SSD
*KEYWORD
*MAT_ELASTIC
*NODE
*PART
*SECTION_SHELL
*SET_NODE_LIST
*SET_SEGMENT
*TITLE
*BOUNDARY_SPC_SET
*CONTROL_FREQUENCY_DOMAIN
*CONTROL_IMPLICIT_EIGENVALUE
*CONTROL_IMPLICIT_GENERAL
*CONTROL_IMPLICIT_SOLUTION
*DATABASE_FREQUENCY_BINARY_D3SSD
*DATABASE_HISTORY_NODE_SET
*DATABASE_NODAL_FORCE_GROUP
*DEFINE_CURVE
*ELEMENT_MASS_NODE_SET
*ELEMENT_SHELL
*END
*FREQUENCY_DOMAIN_SSD
*KEYWORD
*MAT_ELASTIC
*NODE
*PART
*SECTION_SHELL
*SET_NODE_LIST
*SET_SEGMENT
*TITLE
*KEYWORD
*TITLE
A rectangular plate subjected to base acceleration excitation
*FREQUENCY_DOMAIN_SSD
1 20 0.000 0.000 0 0
0.020000 0 0 0.000 0.000
1 2 0
0 0 3 3 100 200 0 0
*DATABASE_FREQUENCY_ASCII_NODOUT_SSD
1.000000 500.00000 500
*DATABASE_FREQUENCY_BINARY_D3SSD
1
1.000000 500.00000 2
*CONTROL_IMPLICIT_EIGENVALUE
20 0.000 0 0.000 0 0.000 0 0.000
0 0 0 0 1
*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 1 0 2 0
0 0 0.000 1 2
*DATABASE_HISTORY_NODE_SET
2 0 0 0 0 0 0 0
*DATABASE_NODAL_FORCE_GROUP
11 0
12 0
*BOUNDARY_SPC_SET
1 0 1 1 1 1 1 1
*SET_NODE_LIST
1 0.000 0.000 0.000 0.000
1 2 3 4 5 6 7 8
9 10 11 0 0 0 0 0
*SET_NODE_LIST
11 0.000 0.000 0.000 0.000
1 2 3 4 5 6 7 8
*SET_NODE_LIST
12 0.000 0.000 0.000 0.000
9 10 11 0 0 0 0 0
*PART
shells
1 1 1 0 0 0 0 0
*SECTION_SHELL
1 18 0.833333 3 0 0 0 0
0.005000 0.005000 0.005000 0.005000 0.000 0.000 0.000 0
*MAT_ELASTIC
1 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
2 0.000 0.000 0.000 0.000
6 556 0 0 0 0 0 0
*SET_SEGMENT
*ELEMENT_SHELL
*NODE
*END
*KEYWORD
*TITLE
A rectangular plate subjected to enforced acceleration excitation
*FREQUENCY_DOMAIN_SSD
1 31 0.000 0.000 0 0
0.020000 0 0 0.000 0.000
1 2 0
1 1 3 6 100 200 0 0
*DATABASE_FREQUENCY_BINARY_D3SSD
1
1.000000 500.00000 2
*CONTROL_FREQUENCY_DOMAIN
2.00e+06
*CONTROL_IMPLICIT_EIGENVALUE
31 0.000 0 0.000 0 0.000 0 0.000
0 0 0 0 1
*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 1 0 2 0
0 0 0.000 1 2
*DATABASE_HISTORY_NODE_SET
2 0 0 0 0 0 0 0
*DATABASE_NODAL_FORCE_GROUP
11 0
12 0
*BOUNDARY_SPC_SET
1 0 1 1 0 1 1 1
*SET_NODE_LIST
1 0.000 0.000 0.000 0.000
1 2 3 4 5 6 7 8
9 10 11 0 0 0 0 0
*SET_NODE_LIST
11 0.000 0.000 0.000 0.000
1 2 3 4 5 6 7 8
*SET_NODE_LIST
12 0.000 0.000 0.000 0.000
9 10 11 0 0 0 0 0
*PART
shells
1 1 1 0 0 0 0 0
*SECTION_SHELL
1 18 0.833333 3 0 0 0 0
0.005000 0.005000 0.005000 0.005000 0.000 0.000 0.000 0
*MAT_ELASTIC
1 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
2 0.000 0.000 0.000 0.000
6 556 0 0 0 0 0 0
*SET_SEGMENT
*ELEMENT_SHELL
*ELEMENT_MASS_NODE_SET
501 1 2.2000000e+07 0
*NODE
*END
