Double Cross In-Plane Vibration — Welcome to LS-DYNA Examples

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Behavior of beam elements in a modal analysis. The problem requires the extraction of numerically close eigenvalues. Differences between Hughes-Liu beam (elform 1), Belytschko-Schwer beam (elform 2) and linear Timoshenko beam (elform 13) can be studied. Example 8 from Introductory Manual for LS-DYNA Users by James M. Kennedy.

Keywords

```*BOUNDARY_SPC_SET
*CONTROL_IMPLICIT_AUTO
*CONTROL_IMPLICIT_EIGENVALUE
*CONTROL_IMPLICIT_GENERAL
*CONTROL_IMPLICIT_SOLVER
*DATABASE_BINARY_D3PLOT
*ELEMENT_BEAM
*END
*KEYWORD
*MAT_ELASTIC
*NODE
*PART
*SECTION_BEAM
*SET_NODE_LIST
*SET_NODE_LIST_GENERATE
*TITLE```

Reduced Input

```*KEYWORD
*TITLE
Pin-Ended Double Cross: In-Plane Vibration
*CONTROL_IMPLICIT_AUTO
1        11        15       0.0       0.0
*CONTROL_IMPLICIT_EIGENVALUE
16    11.000         0 -1.00e+29         0  1.00e+29         2       0.0
*CONTROL_IMPLICIT_GENERAL
1  1.00e-04         2         1         2
*CONTROL_IMPLICIT_SOLVER
16         1         1         0         1       0.0         1       0.0
*DATABASE_BINARY_D3PLOT
0.010000         0         2
*ELEMENT_BEAM
*NODE
*BOUNDARY_SPC_SET
*PART
1         1         1
*SECTION_BEAM
1         1  0.833333       2.0       0.0       0.0
0.125000  0.125000  0.125000  0.125000       0.0       0.0
*MAT_ELASTIC
1  8000.0002.0000e+11  0.300000       0.0       0.0       0.0
*SET_NODE_LIST_GENERATE
1       0.0       0.0       0.0       0.0
2         4         6        24        27        29        31        42
44        46        48        59        61        63        65        76
*SET_NODE_LIST
2       0.0       0.0       0.0       0.0
1         5        30        47        64        60        43        26
*END

```