Home » Knowledge Base » NVH / Fatigue » FRF for a rectangular plate
This example shows how to setup the keywords for FRF computation. A nodal force excitation is defined. Frequency dependent response amplitudes at nodes are computed. Differences between constant and mode dependent modal damping can be studied. Example 4.1 from LS-Dyna training class NVH, Fatigue and Frequency Domain Analysis with LS-DYNA by Yun Huang.
Keywords
*CONTROL_IMPLICIT_EIGENVALUE
*CONTROL_IMPLICIT_GENERAL
*CONTROL_IMPLICIT_NONLINEAR
*CONTROL_SHELL
*DEFINE_CURVE
*ELEMENT_SHELL
*END
*FREQUENCY_DOMAIN_FRF
*KEYWORD
*MAT_ELASTIC
*NODE
*PART
*SECTION_SHELL
*SET_NODE_LIST
*TITLE
*KEYWORD
*TITLE
A rectangular plate for FRF computation.
*FREQUENCY_DOMAIN_FRF
131 0 -3 3 0 2000.0000 0 0
0.000 5 1 0.000 0.000
1 1 3 1
1.000000 400.00000 400 0 0 0
*CONTROL_IMPLICIT_EIGENVALUE
100 0.000 0 0.000 0 0.000 0 0.000
0 0 0 0
*CONTROL_IMPLICIT_GENERAL
1 1.000000 0 0 0 0 0 0
*CONTROL_IMPLICIT_NONLINEAR
1 0 0 0.000 0.000 0.000 0.000 0.000
0 0 0 0
0 0 0.000 1 2
*CONTROL_SHELL
20.000000 2 -1 0 2 2 1 0
1.000000 0 0 1 0 0 0 0
0 0 0
*PART
boxshell
1 1 1 0 0 0 0 0
*SECTION_SHELL
1 6 0.833000 3 3 0 0 0
0.002000 0.002000 0.002000 0.002000 0.000 0.000 0.000 0
*MAT_ELASTIC
1 7870.00002.0700E+11 0.292000 0.000 0.000 0
*DEFINE_CURVE
5 0 0.000 0.000 0.000 0.000 0
1.0000000 0.000
6.0000000 0.000
7.0000000 0.0045000
8.0000000 0.0071300
9.0000000 0.0038600
10.0000000 0.0032800
11.0000000 0.0034000
12.0000000 0.0062400
13.0000000 7.2e-04
14.0000000 8.3e-04
15.0000000 0.000
200.0000000 0.000
*SET_NODE_LIST
1 0.000 0.000 0.000 0.000
131 651 0 0 0 0 0 0
*ELEMENT_SHELL
*NODE
*END
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