*HEADING
 KOYNA DAM: NATURAL FREQUENCY EXTRACTION
 Units - n, m, sec
*PREPRINT, MODEL=YES
*NODE
   1 ,  0.00,   0.00
   21, 70.00,   0.00
 2401,  0.00,  66.50
 2421, 19.25,  66.50
 3601,  0.00,  91.75
 3621, 16.17,  91.75
 3801,  0.00, 103.00
 3821, 14.80, 103.00
*NGEN, NSET=NBASE
 1, 21
*NGEN, NSET=NMID
 2401, 2421
*NGEN, NSET=NWL
 3601, 3621
*NGEN, NSET=NTOP
 3801, 3821
*NFILL, BIAS=1.05
 NBASE, NMID, 24, 100
*NFILL, BIAS=0.92
 NMID, NWL, 12, 100
*NFILL
 NWL, NTOP, 2, 100
*ELEMENT, TYPE=CPS4R
 1, 1, 2, 102, 101
*ELGEN, ELSET=DAM
 1, 20, 1, 1, 38, 100, 100
*ELSET, ELSET=WDAM, GENERATE
 1, 3501, 100
*SOLID SECTION, ELSET=DAM, MATERIAL=CONCRETE
 1.0,
*MATERIAL, NAME=CONCRETE
*ELASTIC
 3.1027E+10, 0.2
*DENSITY
 2643.0
*CONCRETE DAMAGED PLASTICITY
 36.31
*CONCRETE COMPRESSION HARDENING
 13.0E+6, 0.0
 24.1E+6, 0.001
*CONCRETE TENSION STIFFENING, TYPE=DISPLACEMENT
 2.9E+6         ,0
 1.94393E+6     ,0.000066185
 1.30305E+6     ,0.00012286
 0.873463E+6    ,0.000173427
 0.5855E+6      ,0.00022019
 0.392472E+6    ,0.000264718
 0.263082E+6    ,0.000308088
 0.176349E+6    ,0.00035105
 0.11821E+6     ,0.000394138
 0.0792388E+6   ,0.000437744
 0.0531154E+6   ,0.000482165
*CONCRETE TENSION DAMAGE, TYPE=DISPLACEMENT
 0          ,0
 0.381217   ,0.000066185
 0.617107   ,0.00012286
 0.763072   ,0.000173427
 0.853393   ,0.00022019
 0.909282   ,0.000264718
 0.943865   ,0.000308088
 0.965265   ,0.00035105
 0.978506   ,0.000394138
 0.9867     ,0.000437744
 0.99177    ,0.000482165
*BOUNDARY
 NBASE, 1,2
*STEP, NLGEOM
 STEP 1 - GRAVITY LOAD
*STATIC
 1.0E-10, 1.0E-10
*DLOAD
 DAM, GRAV, 9.81, 0, -1
*END STEP
*STEP
 STEP 2 - FREQUENCY EXTRACTION 
*FREQUENCY
 4,
*END STEP