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.
*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
*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
