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Hi Anita,

Thank you for your reply.. I held up with other work so I didn't see the forum.. sorry for that.. I sent an email to you, please check your spam folder as well.

Regards,
Jayanthan

Hi Anita,

I would like to post my script where I placed shear spring at bottom and modeled zerolength barslip as fiber section, but when I place the shear spring at top instead of placing it at bottom, the script is not working properly....

I also sent you an email regarding this long back,

# UBCO
# Sezen (2002)_Specimen1_Flexure Shear Critical Column
# unit kip,inches
# SET UP ------------------------------------------------

# Tags.tcl
set coreTag 1 ;# core concrete
set coverTag 2 ;# cover concrete
set steelTag 3 ;# steel

set coreTagc 6 ;# core concrete
set coverTagc 7 ;# cover concrete
set steelTagc 8 ;# steel

set rigidMatTag 12;
set flexSec 1;
set flexSecc 2;

#--------------------------------------------------------
# Build model
#--------------------------------------------------------
puts "Starting model"
wipe;
source DisplayModel2D.tcl; #procedure for displaying a 2D perspective of model
source DisplayPlane_IR.tcl; #procedure for displaying a plane in a model
set dataDir Sezen(2002)_Specimen1_Result
file mkdir $dataDir;
model BasicBuilder -ndm 2 -ndf 3;

#--------------------------------------------------------
# Define nodal mesh and B.C.s
#--------------------------------------------------------
set L 116;

# tag X Y
node 1 0.0 0.0
node 2 0.0 0.0
node 3 0.0 18
#node 4 0.0 98
#node 5 0.0 $L
node 6 0.0 $L

# tag DX DY RZ
fix 1 1 1 1

#--------------------------------------------------------
# Create column section
#--------------------------------------------------------
# CenterColSecFiber.tcl

set h 18
set b 18

# Set parameters for fiber section
set cover 2;
set Y1 [expr $h/2.0]
set Z1 [expr $b/2.0]

#-----------------------------------------------------------------------------------------
# material for column element
#-----------------------------------------------------------------------------------------
# nominal concrete compressive strength
set fc [expr -3.059]; # CONCRETE Compressive Strength, ksi (+Tension, -Compression)
set Ec [expr 57*sqrt(3059)]; # Concrete Elastic Modulus
# confined concrete
set Kfc 1.1; # ratio of confined to unconfined concrete strength
set fc1C [expr $Kfc*$fc]; # CONFINED concrete (mander model), maximum stress
set eps1C [expr 0.002*(1+5*($Kfc-1))]; #strain at maximum stress
set fc2C [expr 0.9*$fc1C]; # ultimate stress
set eps2C [expr 0.009];# strain at ultimate stress
#set eps2C [expr 3*$eps1C]; # strain at ultimate stress
# unconfined concrete
set fc1U $fc; # UNCONFINED concrete (todeschini parabolic model), maximum stress
set eps1U -0.002; # strain at maximum strength of unconfined concrete
set fc2U [expr ($fc1U/3)]; # ultimate stress
set eps2U -0.006; # strain at ultimate stress
set lambda 3; # ratio between unloading slope at $eps2 and initial slope $Ec
# tensile-strength properties
#set ftC [expr 7.5*sqrt(3.670)]; # tensile strength +tension
#set ftU [expr 7.5*sqrt(3.059)]; # tensile strength +tension
#set Etc [expr (2450/5)]; # tension softening stiffness
#set Etu [expr (3060/5)];
#set Etcb [expr (150/5)]
#set Etub [expr (190/5)]
# -----------
set Fy [expr 63.5]; # STEEL yield stress
set Es [expr 29000]; # modulus of steel
set Bs 0.01; # strain-hardening ratio
set R0 18; # control the transition from elastic to plastic branches
set cR1 0.925; # control the transition from elastic to plastic branches
set cR2 0.15; # control the transition from elastic to plastic branches
#uniaxialMaterial Concrete02 $coreTag $fc1C $eps1C $fc2C $eps2C $lambda $ftC $Etc; # build core concrete (confined)
#uniaxialMaterial Concrete02 $coverTag $fc1U $eps1U $fc2U $eps2U $lambda $ftU $Etu; # build cover concrete (unconfined)

uniaxialMaterial Concrete01 $coreTag $fc1C $eps1C $fc2C $eps2C; # build core concrete (confined)
uniaxialMaterial Concrete01 $coverTag $fc1U $eps1U $fc2U $eps2U; # build cover concrete (unconfined)
uniaxialMaterial Steel02 $steelTag $Fy $Es $Bs $R0 $cR1 $cR2; # build reinforcement material

#-----------------------------------------------------------------------------------------
#Define the fiber section

set barAreaCol 0.99;
section Fiber $flexSec {

# Create the concrete core fibers
patch rect $coreTag 10 1 [expr $cover-$Y1] [expr $cover-$Z1] [expr $Y1-$cover] [expr $Z1-$cover]; # Define the concrete core patch

# Create the concrete cover fibers (top, bottom, left, right)
patch rect $coverTag 10 1 [expr -$Y1] [expr $Z1-$cover] $Y1 $Z1
patch rect $coverTag 10 1 [expr -$Y1] [expr -$Z1] $Y1 [expr $cover-$Z1]
patch rect $coverTag 2 1 [expr -$Y1] [expr $cover-$Z1] [expr $cover-$Y1] [expr $Z1-$cover]
patch rect $coverTag 2 1 [expr $Y1-$cover] [expr $cover-$Z1] $Y1 [expr $Z1-$cover]

# create the reinforcing fibers
layer straight $steelTag 3 $barAreaCol [expr $Y1-$cover] [expr $Z1-$cover] [expr $Y1-$cover] [expr $cover-$Z1]
layer straight $steelTag 2 $barAreaCol 0.0 [expr $Z1-$cover] 0.0 [expr $cover-$Z1]
layer straight $steelTag 3 $barAreaCol [expr $cover-$Y1] [expr $Z1-$cover] [expr $cover-$Y1] [expr $cover-$Z1]
}

#zerolength fiber section material properties
## Core concrete (confined)
uniaxialMaterial Concrete01 $coreTagc $fc1C -0.0500 $fc2C -0.1500 ; # build core concrete (confined)
uniaxialMaterial Concrete01 $coverTagc $fc1U -0.0333 $fc2U -0.1000; # build cover concrete (unconfined)
uniaxialMaterial Steel02 $steelTagc 80 1800 0.01 $R0 $cR1 $cR2; # build reinforcement material

section Fiber $flexSecc {

# Create the concrete core fibers (Confined)
patch rect $coreTagc 10 1 [expr $cover-$Y1] [expr $cover-$Z1] [expr $Y1-$cover] [expr $Z1-$cover]

# Create the concrete cover fibers (top, bottom, left, right)
patch rect $coverTagc 10 1 [expr -$Y1] [expr $Z1-$cover] $Y1 $Z1
patch rect $coverTagc 10 1 [expr -$Y1] [expr -$Z1] $Y1 [expr $cover-$Z1]
patch rect $coverTagc 2 1 [expr -$Y1] [expr $cover-$Z1] [expr $cover-$Y1] [expr $Z1-$cover]
patch rect $coverTagc 2 1 [expr $Y1-$cover] [expr $cover-$Z1] $Y1 [expr $Z1-$cover]

# Create the reinforcing fibers ( top, middle, bottom)
# explanations for the reinforcement placement
# symmetric section
# y
# ^
# |
# --------------------- -- --
# | o o o | | -- cover
# | | |
# | | |
# z <--- | o + o | H
# | | |
# | | |
# | o o o | | -- cover
# --------------------- -- --
# |-------- B --------|
layer straight $steelTagc 3 $barAreaCol [expr $Y1-$cover] [expr $Z1-$cover] [expr $Y1-$cover] [expr $cover-$Z1]
layer straight $steelTagc 2 $barAreaCol 0.0 [expr $Z1-$cover] 0.0 [expr $cover-$Z1]
layer straight $steelTagc 3 $barAreaCol [expr $cover-$Y1] [expr $Z1-$cover] [expr $cover-$Y1] [expr $cover-$Z1]
}

#--------------------------------------------------------
# Define the beam-column element
#--------------------------------------------------------
geomTransf PDelta 1


#Distributed Plasticity Elements
set nint 5
element zeroLengthSection 2 1 2 $flexSecc -orient 0 1 0 1 0 0;
element nonlinearBeamColumn 11 2 3 $nint $flexSec 1 -iter 6 1e-12
element nonlinearBeamColumn 12 3 6 $nint $flexSec 1 -iter 6 1e-12
#element forceBeamColumn 13 4 5 $nint $flexSec 1 -iter 5 1e-12

#Calibrated Input for shear spring--------------------------------
#limitCurve RotationShearCurve $crvTag $eleTag $ndI $ndJ $rotAxis $Vn $Vr $Kdeg $defType $b $d $h $L $st $As $Acc $ld $db $rhot $f'c $fy $fyt $delta
limitCurve RotationShearCurve 2 11 1 3 3 -1 -1 0 1 18 15.44 18 116 12 7.99 256 56 1.128 0.0015 -3.059 63.5 69.02 0.0

#uniaxialMaterial PinchingLimitStateMaterial $matTag $nodeT $nodeB $driftAxis $Kelas $crvTyp $crvTag $eleTag $b $d $h $a $st $As $Acc $ld $db $rhot $f'c $fy $fyt
uniaxialMaterial PinchingLimitStateMaterial 9 6 2 1 -3 2 2 11 18 15.44 18 58 12 7.99 256 56 1.128 0.0015 -3.059 63.5 69.02
#limitCurve RotationShearCurve 3 13 6 4 3 0 -1 0 1 18 15.44 18 116 12 7.99 256 56 1.128 0.0017 -3.059 63.5 69.02 0.0
#uniaxialMaterial PinchingLimitStateMaterial 10 5 1 1 -3 2 3 13 18 15.44 18 58 12 7.99 256 56 1.128 0.0017 -3.059 63.5 69.02

#--------------------------------------------------------
# Define the zero-length end springs
#--------------------------------------------------------

#bottom of column slip spring

element zeroLength 1 1 2 -mat 9 -dir 1

#--------------------------------------------------------
# Define GRAVITY Load
#--------------------------------------------------------
# Define Axial Load
set P [expr 150]

timeSeries Linear 1
pattern Plain 1 1 {
load 6 0 [expr -$P] 0
}

# Gravity-analysis parameters -- load-controlled static analysis
set Tol 1.0e-6; # convergence tolerance for test
constraints Plain; # how it handles boundary conditions
numberer Plain; # renumber dof's to minimize band-width (optimization), if you want to
system BandGeneral; # how to store and solve the system of equations in the analysis
test NormDispIncr $Tol 6 ; # determine if convergence has been achieved at the end of an iteration step
algorithm Newton; # use Newton's solution algorithm: updates tangent stiffness at every iteration
set NstepGravity 10; # apply gravity in 10 steps
set DGravity [expr 1./$NstepGravity]; # first load increment;
integrator LoadControl $DGravity; # determine the next time step for an analysis
analysis Static; # define type of analysis static or transient
puts "Check"
analyze $NstepGravity; # apply gravity
# ------------------------------------------------- maintain constant gravity loads and reset time to zero
puts "Check"
loadConst -time 0.0

puts "Model Built"
# display deformed shape:
set ViewScale 5;
DisplayModel2D DeformedShape $ViewScale ; # display deformed shape, the scaling factor needs to be adjusted for each model

#--------------------------------------------------------
# Recorders
#--------------------------------------------------------

# record displacements for node with applied displacement
recorder Node -file $dataDir/TopDisp.out -time -node 6 -dof 1 disp
recorder Node -file $dataDir/RX.out -time -node 1 -dof 1 reaction

source Cyclic.tcl


Regards,
Jayanthan

Hi Anita,

Thanks for replying my post. I am also facing the same issue. Initially, I tried LeBorgne's model for sezen column with one shear spring at the bottom of the column that seems to work fine, where I used calibrated input but I am not getting the perfect degrading slope for shear spring. Then, I introduced shear spring at top and bottom, it is not working properly.
Another question, I need to ask, Do we need to use zero length section for defining bar slip fiber section (as given the LeBorgne's paper)?
If you wish, I can also email my opensees code with you.

Thanks & Regards
Jayanthan
m.jayanth1992@gmail.com

Hi Anita,

This is Jayanthan from UBC, Canada. I am also working on shear critical column. As you used LeBorgne's shear critical model, I too use the same. Could you please tell me how you calculated the stiffness value for rotational spring in soft material and rigid material tag?

Thanks & Regards
Jayanthan
m.jayanth1992@gmail.com

Hi alirezacivil,

I used this manual for defining value Vi1, Vi2 and Vi3 as given in the manual. I end up in error, displayed as failed to update for displacement control (new void).
Could you please share me your opensees code for the column with shear spring problem.

Kind regards,
Jayanthan
m.jayanth1992@gmail.com

Hi alireza,

I am also modeling column with shear critical.. I would like to know how to calculate the value of Vi1,Vi2 and Vi3 values for assigned shear spring material model?
Could you please help me out?

Thanks
Jayanthan