*HEADING
: EIGENVALUE ANALYSIS OF AN UNCONSTRAINED 1-ELEMENT MESH  [M3D9R]
*PREPRINT,ECHO=YES,HISTORY=NO,MODEL=NO
*NODE
*NGEN
*ELEMENT,TYPE=M3D9R, ELSET=EALL
*MEMBRANE SECTION,MATERIAL=A1, ELSET=EALL
.1,
*MATERIAL,NAME=A1
*ELASTIC
3.E6      , 0.3
*DENSITY
7.5E-4,
*STEP
*FREQUENCY, eigensolver=lanczos
19, , ,-1.E7
*OUTPUT,HISTORY,FREQUENCY=1
*MODAL OUTPUT
*END STEP