Nonlinear static analysis of cylinder with horizontal load at the top.

While i am implementing Nonlinear static analysis of cylinder with horizontal load at the top the failure happens very early before reaching the maximum stress of concrete or steel please help.


Also please find here my used code:


!********************!  1-preferance  !********************!  

/OUTPUT,pushover withOUT openingD7 1.5hd 1 percent,out    !####! TO MAKE OUTOUTS IN SEPARATE FILE AS MASS PARTICIPATION FACTOR  

/NOPR  

KEYW,PR_SET,1  

KEYW,PR_STRUC,1 

KEYW,PR_THERM,0 

KEYW,PR_FLUID,0 

KEYW,PR_ELMAG,0 

KEYW,MAGNOD,0  

KEYW,MAGEDG,0  

KEYW,MAGHFE,0  

KEYW,MAGELC,0  

KEYW,PR_MULTI,0 

KEYW,PR_CFD,0  

/GO 

!********************!  2-reprocesses !********************! 

/PREP7

ET,1,SOLID65    !###! concrete element

ET,2,SOLID65    !###! Grains

!********************!  3-material concrete & grain & reinforcement !********************! 

!*  

MPTEMP,,,,,,,,  

MPTEMP,1,0  

MPDE,DENS,1 

MPDATA,DENS,1,,2.5E-005 

MPTEMP,,,,,,,,  

MPTEMP,1,0  

MPDE,EX,1  

MPDE,NUXY,1 

MPDE,PRXY,1 

MPDATA,EX,1,,33346  

MPDATA,PRXY,1,,0.2  

TBDE,CONC,1,,,  

TB,CONC,1,1,9,  

TBTEMP,0

TBDATA,,0.3,0.7,3.95,32,0,0 

TBDATA,,0,0,0,,,

TBDE,MELA,1,,,  

TB,MELA,1,1,18, 

TBTEMP,0

TBPT,,0.0002,6.6692 

TBPT,,0.0004,11.948 

TBPT,,0.0006,16.88  

TBPT,,0.0008,21.117 

TBPT,,0.001,24.659  

TBPT,,0.0012,27.506 

TBPT,,0.0014,29.658 

TBPT,,0.0016,31.114 

TBPT,,0.0018,31.876 

TBPT,,0.001919,32  

TBPT,,0.0022,31.148 

TBPT,,0.0024,30.54  

TBPT,,0.0026,29.933 

TBPT,,0.0028,29.326 

TBPT,,0.003,28.718  

TBPT,,0.0032,28.111 

TBPT,,0.0034,27.504 

TBPT,,0.0035,27.2  

MPTEMP,,,,,,,,  

MPTEMP,1,0  

MPDE,DENS,2 

MPDATA,DENS,2,,2.0918E-009  

MPTEMP,,,,,,,,  

MPTEMP,1,0  

MPDE,EX,2  

MPDE,NUXY,2 

MPDE,PRXY,2 

MPDATA,EX,2,,1.361E+005 

MPDATA,PRXY,2,,0.36 

MPTEMP,,,,,,,,  

MPTEMP,1,0  

MPDE,DENS,3 

MPDATA,DENS,3,,7.85E-005

MPTEMP,,,,,,,,  

MPTEMP,1,0  

MPDE,EX,3  

MPDE,NUXY,3 

MPDE,PRXY,3 

MPDATA,EX,3,,2.1E+005  

MPDATA,PRXY,3,,0.3  

TBDE,BISO,3,,,  

TB,BISO,3,1,2,  

TBTEMP,0

TBDATA,,360,5000,,,,

!********************!  4-REAL CONSTANT FOR RFT  !********************! 

!********************!  5-define Volume  !********************! 

CYL4, , ,1500, ,1425, ,6000 

CYL4, , ,1425, ,1350, ,6000 

LPLOT

!********************!  6-GLUE!********************! 

FLST,2,2,6,ORDE,2  

FITEM,2,1  

FITEM,2,-2  

VGLUE,P51X  

FLST,2,10,5,ORDE,4  

FITEM,2,1  

FITEM,2,-6  

FITEM,2,11  

FITEM,2,-14 

AGLUE,P51X  

FLST,2,30,4,ORDE,8  

FITEM,2,1  

FITEM,2,-20 

FITEM,2,25  

FITEM,2,-28 

FITEM,2,33  

FITEM,2,-36 

FITEM,2,39  

FITEM,2,-40 

LGLUE,P51X  

!********************!  6-Meshing!********************! 

!* 1- top & bottom

FLST,5,24,4,ORDE,6  

FITEM,5,1  

FITEM,5,-16 

FITEM,5,25  

FITEM,5,-28 

FITEM,5,33  

FITEM,5,-36 

CM,_Y,LINE  

LSEL, , , ,P51X 

CM,_Y1,LINE 

CMSEL,,_Y  

!*  

LESIZE,_Y1, , ,12, , , , ,0 

!*  

!* 2-wall

FLST,5,6,4,ORDE,4  

FITEM,5,17  

FITEM,5,-20 

FITEM,5,39  

FITEM,5,-40 

CM,_Y,LINE  

LSEL, , , ,P51X 

CM,_Y1,LINE 

CMSEL,,_Y  

!*  

LESIZE,_Y1, , ,30, , , , ,0 

!*  

!*VSWEEP

FLST,5,2,6,ORDE,2  

FITEM,5,1  

FITEM,5,3  

CM,_Y,VOLU  

VSEL, , , ,P51X 

CM,_Y1,VOLU 

CMSEL,S,_Y  

!*  

CMSEL,S,_Y1 

VATT,    1, ,  1,    0  

CMSEL,S,_Y  

CMDELE,_Y  

CMDELE,_Y1  

!*  

FLST,5,2,6,ORDE,2  

FITEM,5,1  

FITEM,5,3  

CM,_Y,VOLU  

VSEL, , , ,P51X 

CM,_Y1,VOLU 

CHKMSH,'VOLU'  

CMSEL,S,_Y  

!*  

VSWEEP,_Y1  

!*  

CMDELE,_Y  

CMDELE,_Y1  

CMDELE,_Y2  

!* 

!********************!  4-REAL CONSTANT FOR RFT  !********************! 

!*  

ET,4,LINK180

!*  

!*  

R,2,1500, ,0 

!* 

!********************!  5-create keypoints  !********************! 

FLST,3,4464,1,ORDE,2

FITEM,3,1  

FITEM,3,-4464  

KNODE,0,P51X

! *******! 6- reinforcement

LSTR,73,   3728

LSTR,74,   3729

LSTR,75,   3730

LSTR,76,   3731

LSTR,77,   3732

LSTR,78,   3733

LSTR,79,   3734

LSTR,80,   3735

LSTR,81,   3736

LSTR,82,   3737

LSTR,83,   3738

LSTR,84,   3716

LSTR,85,   3717

LSTR,86,   3718

LSTR,87,   3719

LSTR,88,   3720

LSTR,89,   3721

LSTR,90,   3722

LSTR,91,   3723

LSTR,92,   3724

LSTR,93,   3725

LSTR,94,   3727

LSTR,95,   3726

LSTR,96,   4478

LSTR,97,   4479

LSTR,98,   4480

LSTR,99,   4481

LSTR,100,   4482

LSTR,101,   4483

LSTR,102,   4484

LSTR,103,   4485

LSTR,104,   4486

LSTR,105,   4487

LSTR,106,   3769

LSTR,107,   4488

LSTR,108,   3739

LSTR,109,   4466

LSTR,110,   4467

LSTR,111,   4468

LSTR,112,   4469

LSTR,113,   4470

LSTR,114,   4471

LSTR,115,   4472

LSTR,116,   4473

LSTR,117,   4474

LSTR,118,   4475

LSTR,119,   4477

LSTR,120,   4476

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

! *******! 8-Mesh reinforcement section

FLST,5,48,4,ORDE,8  

FITEM,5,21  

FITEM,5,-24 

FITEM,5,29  

FITEM,5,-32 

FITEM,5,37  

FITEM,5,-38 

FITEM,5,41  

FITEM,5,-78 

CM,_Y,LINE  

LSEL, , , ,P51X 

CM,_Y1,LINE 

CMSEL,,_Y  

!*  

LESIZE,_Y1, , ,30, , , , ,0 

!*  

TYPE,  4  

MAT,    3

REAL,    2  

ESYS,    0  

SECNUM, 

!*  

FLST,2,48,4,ORDE,8  

FITEM,2,21  

FITEM,2,-24 

FITEM,2,29  

FITEM,2,-32 

FITEM,2,37  

FITEM,2,-38 

FITEM,2,41  

FITEM,2,-78 

LMESH,P51X  

! *******! 7- HZ reinforcement

FLST,3,4,4,ORDE,2  

FITEM,3,5  

FITEM,3,-8  

LGEN,30,P51X, , , , ,200, ,0

TYPE,  4  

MAT,    3

REAL,    2  

ESYS,    0  

SECNUM, 

!*  

FLST,2,120,4,ORDE,4 

FITEM,2,5  

FITEM,2,-8  

FITEM,2,79  

FITEM,2,-194

LMESH,P51X 

TYPE,  4  

MAT,    3

REAL,    2  

ESYS,    0  

SECNUM, 

!*  

FLST,2,4,4,ORDE,2  

FITEM,2,13  

FITEM,2,-16 

LMESH,P51X  

ALLSEL,ALL  

/REPLOT 

EPLOT 

NUMMRG,NODE, , , ,LOW  

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!1

FLST,2,24,1,ORDE,2  

FITEM,2,812 

FITEM,2,-835

!*  

/GO 

F,P51X,FX,100000

FLST,2,1,1,ORDE,1  

FITEM,2,865 

!*  

/GO 

F,P51X,FX,100000

FLST,2,23,1,ORDE,2  

FITEM,2,1562

FITEM,2,-1584  

!*  

/GO 

F,P51X,FX,100000

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!1

FLST,2,144,1,ORDE,2 

FITEM,2,1  

FITEM,2,-144

!*  

/GO 

D,P51X, , , , , ,ALL, , , , ,  

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!1

/SOL

!*  

ANTYPE,0

DELTIM,250,150,2500 

OUTRES,ERASE

OUTRES,ALL,ALL  

RESCONTRL,DEFINE,ALL,ALL,0  

TIME,4800000

!*  

CNVTOL,F, ,0.05,2, ,

!* 

!*  

ALLSEL,ALL  

EPLOT 

Answers

  • jjdoylejjdoyle PittsburghMember

    You have a negative tangent stiffness slope for material #1 as indicated by the following error.

    Also, you are applying a force based load.

    This looks like a simple enough model.

    After you fix the material input, try replacing the force with a displacement for stability.

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