*HEADING
: EIGENVALUE ANALYSIS OF AN UNCONSTRAINED PATCH OF ELEMENTS  [S4R5]
*PREPRINT,ECHO=YES,HISTORY=NO,MODEL=NO
*NODE,NSET=ALL
10,0,0
20,.24,0.
30,.24,.12
40,0.,.12
102,.04,.02
104,.18,.03
204,.16,.08
202,.08,.08
*ELEMENT,TYPE=S4R5, ELSET=EALL
1,10,20,104,102
2,10,102,202,40
3,102,104,204,202
4,104,20,30,204
5,202,204,30,40
*SHELL SECTION,MATERIAL=A1, ELSET=EALL
.001, 
*MATERIAL,NAME=A1
*ELASTIC,TYPE=ISOTROPIC
1.E6,.25
*DENSITY
7.5E-4, 
*NSET,NSET=SIDES,GENERATE
10,40,10
*STEP
*FREQUENCY, eigensolver=lanczos, SIM=NO
 9, , ,-1.E7
*OUTPUT,HISTORY,FREQUENCY=1
*MODAL OUTPUT
*END STEP