*HEADING
 RIKS ANALYSIS OF CYLINDER BUCKLING 
 (1% thickness,*IMPERFECTION) 
*NODE
 10,  100.,0.,0.
 18,  70.71,0.,70.71
 410, 100.,400.,0.
 418, 70.71,400.,70.71
*NGEN,LINE=C,NSET=LOADB
 10,18,1,,0.,0.,0.
*NGEN,LINE=C,NSET=BND3
 410,418,1, ,0.,400.,0.
*IMPERFECTION, FILE=bucklecylshell_s4r5_n1, STEP=1
 1,0.0025
*NGEN,NSET=BND1
 10,410,40
*NGEN,NSET=REST
 11,411,40
 12,412,40
 13,413,40
 14,414,40
 15,415,40
 16,416,40
 17,417,40
*NGEN,NSET=BND2
 18,418,40
*NSET,NSET=ALL
 BND1,BND2,BND3,REST
*NSET,NSET=LDB1
 10,18
*NSET,NSET=LDB2,GENERATE
 11,17
*NSET,NSET=LDBFIL
 LDB1,LDB2
*TRANSFORM,TYPE=C,NSET=ALL
 0.,0.,0., 0.,1.,0.
*BOUNDARY
 BND1,YSYMM
 BND2,YSYMM
 BND3,ZSYMM
 LOADB,1,2
 LOADB,4
 LOADB,6
*ELEMENT,TYPE=S4R5
 1, 10,50,51,11
*ELGEN,ELSET=EALL
 1,8,1,1,10,40,10
*SHELL SECTION,ELSET=EALL,MATERIAL=MAT
 .25, 
*MATERIAL,NAME=MAT
*ELASTIC
 30.E6,.3
*RESTART,WRITE
**
*STEP,NLGEOM,INC=60
*STATIC,RIKS
 .1,1.,,,,14,3,.6
*CLOAD
 LDB1,3, 49969.31158
 LDB2,3, 99938.62316
*EL PRINT, FREQUENCY=99
 S,E,
*EL FILE,FREQUENCY=99
 S,E,
*NODE PRINT,NSET=LDBFIL,FREQUENCY=2,GLOBAL=NO
 U, 
 CF, 
 RF, 
*NODE FILE,FREQUENCY=1,NSET=LDBFIL,GLOBAL=NO
 U,CF,RF
*MONITOR,NODE=14,DOF=3
*END STEP