*HEADING
: EIGENVALUE ANALYSIS OF AN UNCONSTRAINED 1-ELEMENT MESH  [ELBOW31C]
*NODE,NSET=ALL
1,0.
2,15.
*ELEMENT,TYPE=ELBOW31C, ELSET=EALL
1,1,2
*BEAM SECTION,SECTION=ELBOW,TEMPERATURE=VALUES,MATERIAL=MAT1, ELSET=EALL
10.,1.,0.
15.,1.
3,18,6
*MATERIAL,NAME=MAT1
*ELASTIC
3.E6,.3
*DENSITY
7.5E-4, 
*STEP
*FREQUENCY, eigensolver=lanczos
10, , ,-8500.
*OUTPUT,FIELD,FREQUENCY=0
*MODAL OUTPUT
*END STEP