*HEADING
: EIGENVALUE ANALYSIS OF AN UNCONSTRAINED PATCH OF ELEMENTS  [CPEG6]
*PREPRINT,ECHO=YES,HISTORY=NO,MODEL=NO
*NODE
1000,0,0
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
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
40,102,31
20,102,41
104,202,49
30,202,86
30,104,37
*ELEMENT,TYPE=CPEG6, ELSET=EALL
1,   10,102, 40, 56, 71, 80
2,   10, 20,102, 50, 61, 56
3,  102,202, 40,152,121, 71
4,  202, 30, 40,116, 70,121
5,  102, 20,104, 61, 62,103
6,  102,104,202,103,153,152
7,  202,104,204,153,154,203
8,  202,204, 30,203,117,116
9,  104, 30,204, 67,117,154
10, 104, 20, 30, 62, 60, 67
*SOLID SECTION,MATERIAL=A1,ELSET=EALL,REFNODE=1000
.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
5, , ,-1.E7 
*MODAL FILE
*OUTPUT,HISTORY,FREQUENCY=1
*MODAL OUTPUT
*CONTROLS,PARAMETERS=FIELD
1.E-14, 1., , , 1.E-12
*END STEP
*STEP,NLGEOM
*STATIC
*DLOAD
1, P3, -10000.
2, P1, -10000.
4, P2, -10000.
10, P2, -10000.
*BOUNDARY
10,1,2
20,2
*EL PRINT,FREQ=0
*NODE PRINT
U, 
RF, 
*END STEP
*STEP,NLGEOM
*FREQUENCY, eigensolver=lanczos, SIM=NO
5, , , -1.E7 
*MODAL FILE
*OUTPUT,HISTORY,FREQUENCY=1
*MODAL OUTPUT
*EL PRINT,FREQ=0
*NODE PRINT,FREQ=0
*BOUNDARY,OP=NEW
*END STEP