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a problem in simulating reinforced concrete column in ANSYS

Submitted by DavidMartin on

Greetings,

 

 while trying to simulate reinforced concrete column in ANSYS, i've encounterd the following problem,  

 

" The supplied nonlinaer material properties produced an incorrect material tangent matrix. please check your TB input carefully. a very small yield stress may cause this failure " .!

ive checked material properties section, all seems alright, still having convergence problems, specially when loads exceeds concrete compressive strength (fc') .! this is all on plain concrete, before "reinforcing" it .!

 

any suggestions, tips, that might help overcoming the problem is more than welcomed :) .!

 

all the best 

it's always greater than Ex from TB table .! i'm using multilinear curve where modulus of elasticity is always less than the initial EX. 

i've got two problems, the one with the tangent modulus, and the second is that  when a message appears telling me i've got rigid bodt motion .!

i'm including the code, will you check it out and pinpoint the error place ?! i'd be more than gratfull :).

!!! Plain Concrete

!!! LOAD = 27 MPA

!!! Constaint at base = FIX

!!! Crushing elements at the base .!

Finish

/Clear

/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

/Prep7

/TITLE,SpOQuarterColumn125mm

! Create Elements (CONCRETE AND STEEL) and Assigning Real Constans

ET,1,SOLID65

type,1

R,1

KEYOPT,1,7,1

!ET,2,LINK180

!type,2

!R,2,1.53938e-4

!R,3,5.02654e-5

! Material Properties

/UNITS,USER,1,1,1,1,1,1,1000000,1



! Concrete Material Properties (Linear+Multilinaer+Concrete Coef)

MP,EX,1,24580

MP,PRXY,1,0.3

TB,CONCR,1

TBDATA,1,0.3,1,2.7,-1

!,32.4

!TBDATA,6,46.76,39.15,46.575

TB,MISO,1

TBTEMP,0

TBPT,DEFI,0.0003,07.3779

TBPT,DEFI,0.0006,13.7306

TBPT,DEFI,0.0012,22.7245

TBPT,DEFI,0.0018,26.4754

TBPT,DEFI,0.0021,27.0000



! Steel Material Properties

!MP,EX,2,200000

!MP,PRXY,2,0.3

!TB,BISO,2

!TBDATA,1,410,0

!Create a Block Volumne Concrete

BLOCK,0,0.125,0,1.3,0,0.125

VPlot



!Create Keypoints for reinforcement

!k,100,0.01,0,0.01

!k,101,0.01,1.2,0.01

!k,102,0.125,0.2,0.01

!k,103,0.01,0.2,0.01

!k,104,0.01,0.2,0.125

!k,105,0.125,0.4,0.01

!k,106,0.01,0.4,0.01

!k,107,0.01,0.4,0.125

!k,108,0.125,0.6,0.01

!k,109,0.01,0.6,0.01

!k,110,0.01,0.6,0.125

!k,111,0.125,0.8,0.01

!k,112,0.01,0.8,0.01

!k,113,0.01,0.8,0.125

!k,114,0.125,1,0.01

!k,115,0.01,1,0.01

!k,116,0.01,1,0.125

!k,117,0.125,1.2,0.01

!k,118,0.01,1.2,0.01

!k,119,0.01,1.2,0.125

! Create Lines - Reinforcement Steel (Long. and Trans.)

!L,100,101

!L,102,103

!L,103,104

!L,105,106

!L,106,107

!L,108,109

!L,109,110

!L,111,112

!L,112,113

!L,114,115

!L,115,116

!L,117,118

!L,118,119



! MESHING

! Volume Meshing

ESIZE,0.05

TYPE,1

MAT,1

REAL,1

VSWEEP,ALL

!TYPE,2

!MAT,2

!REAL,2

!LMESH,13



!TYPE,2

!MAT,2

!REAL,3

!LMESH,14

!LMESH,15

!LMESH,16

!LMESH,17

!LMESH,18

!LMESH,19

!LMESH,20

!LMESH,21

!LMESH,22

!LMESH,23

!LMESH,24

!LMESH,25

!!! Definition of Constraint

/VIEW,1,1,2,3  

/ANG,1

/REPLOT

FLST,2,2,5,ORDE,2  

FITEM,2,2  

FITEM,2,6  

DA,P51X,SYMM

FLST,2,1,5,ORDE,1  

FITEM,2,3  

DA,P51X,ALL,

!!! Definition of Loads

FLST,2,1,5,ORDE,1  

FITEM,2,4  

SFA,P51X,1,PRES,28



!! SOLUTION PARAMETERS



/SOL

ANTYPE,0

CNVTOL,F, ,0.05,2,-1,  

CNVTOL,U, ,0.005,2,-1 ,

DELTIM,0.01,0.01,0.01  

TIME,1

CUTCONTROL,CRPLIMITexp,.1,0

CUTCONTROL,DSPLIMIT,10e6

CUTCONTROL,PLSLIMIT,.15

NCNV,2,0,0,0,0

AUTOTS,1

NEQIT,100

NROPT,FULL

LNSRCH,ON

NLGEOM,0

EQSLV,SPAR

SOLVE

Sun, 04/29/2012 - 12:24 Permalink

Hi! Have you solved this "fatal error" problem? I have the same difficulties with my modell (reinforced semi preacast slab in case of erection).

--> nonlinear concrete (Miso)  Ex=30000N/mm2,  first point= 9/Ex, 9   [N/mm2].   So this doesnt cause this exit fatal error.

Any suggestions? (its my master thesis)

Sun, 09/21/2014 - 15:35 Permalink