*HEADING
: EIGENVALUE ANALYSIS OF AN UNCONSTRAINED PATCH OF ELEMENTS  [STRI65]
*PREPRINT,ECHO=YES,HISTORY=NO,MODEL=NO
*NODE,NSET=ALL
10,0,0
20,.24,0.
30,.24,.12
40,0.,.12
50,.12,0.
60,.24,.06
70,.12,.12
80,.0,.06
102,.04,.02
104,.18,.03
204,.16,.08
202,.08,.08
*NGEN,NSET=ALL
102,104
202,204
102,202,50
104,204,50
10,102,46
40,202,81
30,204,87
20,104,42
10,40,15
10,104,47
10,202,96
102,204,51
30,104,37
30,202,86
*ELEMENT,TYPE=STRI65, ELSET=EALL
    1,    10,    20,   104,    50,    62,    57
50001,    10,   104,   102,    57,   103,    56
    2,    10,   102,   202,    56,   152,   106
50002,    10,   202,    40,   106,   121,    80
    3,   102,   104,   204,   103,   154,   153
50003,   102,   204,   202,   153,   203,   152
    4,   104,    20,    30,    62,    60,    67
50004,   104,    30,   204,    67,   117,   154
    5,   202,   204,    30,   203,   117,   116
50005,   202,    30,    40,   116,    70,   121
*SHELL SECTION,MATERIAL=A1, ELSET=EALL
.001, 
*MATERIAL,NAME=A1
*ELASTIC,TYPE=ISOTROPIC
1.E6,.25
*DENSITY
7.5E-4, 
*NSET,NSET=SIDES,GENERATE
10,80,10
*STEP
*FREQUENCY, eigensolver=lanczos, SIM=NO
 8, , ,-1.E7
*OUTPUT,HISTORY,FREQUENCY=1
*MODAL OUTPUT
*END STEP