*HEADING
: EIGENVALUE ANALYSIS OF AN UNCONSTRAINED 1-ELEMENT MESH  [B31OSH]
*NODE,NSET=NALL
1,0.
2,1.,2.,3,
*ELEMENT,TYPE=B31OSH, ELSET=EALL
1,1,2
*BEAM SECTION,SECTION=I,MATERIAL=A1, ELSET=EALL
5.,10.,10.,10.,1.,1.,1.
*MATERIAL,NAME=A1
*ELASTIC
30.E6, 
*DENSITY
7.5E-4, 
*STEP
*FREQUENCY, eigensolver=lanczos
12, , ,-1.0E4
*END STEP