C02 doesn't work !

[Jfoyian]

Hi,

I have had a problem for a long time on running pushover analysis for RC shear walls and the results that I have obtained are pretty weird- I was getting a unreasonably small capacity. I played with almost all parameters but it didn't work. The materials I use are hysteretic steel and C02 type concrete. I just copied the associated material property lines from the examples, therefore I wasn't suspicious about them. However, when I do the moment-curvature analysis for a simple beam in Opensees, I realized that the moment capacity is again too small, which is around 1/4 of the value it was supposed to be. And no matter what I input for f'c, even 10 times f'c does not increase the capacity to the level it has to be which doesn't make any sense. Now I am pretty sure that C02 is not working well or something is definitrly wrong. I am attaching that moment-curvature analysis script and I would really appreciate any comments and help from you.

Thanks.

# SET UP ----------------------------------------------------------------------
wipe; # clear opensees model
model basic -ndm 2 -ndf 3; # 2 dimensions, 3 dof per node
file mkdir Data_1EQ; # create data directory
source LibUnits.tcl; # define units


# MATERIAL parameters ------------

set IDconcCover 1; # material ID tag -- unconfined concrete
set IDreinf 2; # material ID tag -- boundary reinforcement (#3 rebars) # material ID tag -- web reinforcement (#2 rebars)
set FiberSecTag 3;
# ---------------------------------------------STEEL-----------------------------------------------------------------
uniaxialMaterial Hysteretic $IDreinf 68 0.002345 100 0.05 1 0.06 -68 -0.002345 -100 -0.05 -1 -0.06 0.5 0.5 0 0 0;

#UNCONFINED CONCRETE MATERIAL 0

#uniaxialMaterial Concrete07 $IDconcCover $fcU $ecU $EcU $ftU $etU $xpU $xnU 7.8
uniaxialMaterial Concrete02 $IDconcCover -61 -0.027 -1.4 -0.01 0.1 0.586 410;


# FIBER SECTIONS

section Fiber $FiberSecTag {
#concrete
patch quad $IDconcCover 10 15 -5 -15 5 -15 5 15 -5 15
#bottom boundary steel left
layer straight $IDreinf 1 3 0 -13.5 0 -13.5;
}
# define procedure
source MomentCurvature.tcl

# set AXIAL LOAD --------------------------------------------------------
set P [expr 0.0*$kip]; # + Tension, - Compression

# set maximum Curvature:
set Ku [expr 0.2/$in];
set numIncr 1000; # Number of analysis increments to maximum curvature (default=100)
# Call the section analysis procedure
MomentCurvature $FiberSecTag $P $Ku $numIncr

[silvia]

please make little modifications to the examples manual at a time.
something is weird about your reinforcement layer.

concrete02 works very well, so you should check your model carefully and make sure you are not getting errors/complaints from opensees.