Hi all
I have the Cantilever column do the Static Reversed CyclicAnalysis ,the Cantilever column is a concrete-filled steel tube.Now I face a problem that the peak of each cycle is getting higher and higher in the P-Delta Curve ,which is just the opposite with the test curve .I use the fiber section and concrete 02 with steel 02
How can we explain this issue ? Thank you very much
concrete-filled steel tube
Moderators: silvia, selimgunay, Moderators
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zhangchuanchao
- Posts: 29
- Joined: Wed Oct 15, 2008 2:01 am
- Location: china
-
zhangchuanchao
- Posts: 29
- Joined: Wed Oct 15, 2008 2:01 am
- Location: china
-
zhangchuanchao
- Posts: 29
- Joined: Wed Oct 15, 2008 2:01 am
- Location: china
I am sorry,I can not understand .The direction is set DoF 1 of Nod 2 .
This is my procedure, Thank you for help me
# units: mm, n, sec
wipe; # clear memory of all past model definitions
file mkdir Data; # create data directory
model BasicBuilder -ndm 2 -ndf 3; # Define the model builder, ndm=#dimension, ndf=#dofs
# define GEOMETRY -------------------------------------------------------------
set LCol 1092; # column length
set Weight 2462702.; # superstructure weight
# calculated parameters
set PCol $Weight; # nodal dead-load weight per column
set g 9800; # g.
set Mass [expr $PCol/$g]; # nodal mass
# calculated geometry parameters
set ACol 58533; # cross-sectional area
# nodal coordinates:
node 1 0 0; # node#, X, Y
node 2 0 $LCol
# Single point constraints -- Boundary Conditions
fix 1 1 1 1; # node DX DY RZ
# nodal masses:
mass 2 $Mass 1e-9 0.; # node#, Mx My Mz, Mass=Weight/g, neglect rotational inertia at nodes
# Define ELEMENTS & SECTIONS -------------------------------------------------------------
set ColSecTag 1; # assign a tag number to the column section
# define section geometry
# MATERIAL parameters -------------------------------------------------------------------
set IDconcU 1; # material ID tag -- unconfined cover concrete
set IDreinf 2; # material ID tag -- reinforcement
# nominal concrete compressive strength
set fc -132.86; # CONCRETE Compressive Strength (+Tension, -Compression)
set Ec 40000.; # Concrete Elastic Modulus (the term in sqr root needs to be in psi
# unconfined concrete
set fc1U $fc; # UNCONFINED concrete (todeschini parabolic model), maximum stress
set eps1U -0.0137; # strain at maximum strength of unconfined concrete
set fc2U [expr 0.2*$fc1U]; # ultimate stress
set eps2U -0.05; # strain at ultimate stress
set lambda 0.1; # ratio between unloading slope at $eps2 and initial slope $Ec
# tensile-strength properties
set ftU 13.2; # tensile strength +tension
set Ets [expr $ftU/0.002]; # tension softening stiffness
# -----------
set Fy 372.; # STEEL yield stress
set Es 210000.; # modulus of steel
set Bs 0.01; # strain-hardening ratio
set R0 10; # 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 $IDconcU $fc1U $eps1U $fc2U $eps2U $lambda $ftU $Ets; # build cover concrete (unconfined)
uniaxialMaterial Steel02 $IDreinf $Fy $Es $Bs $R0 $cR1 $cR2; # build reinforcement material
section fiberSec $ColSecTag {; # Define the fiber section
patch circ $IDconcU 8 8 0.0 0.0 0.0 155.6 0.0 360.0; # Define the concrete patch
patch circ $IDreinf 8 8 0.0 0.0 130.0 162.0 0.0 360.0;
}; # end of fibersection definition
# define geometric transformation: performs a linear geometric transformation of beam stiffness and resisting force from the basic system to the global-coordinate system
set ColTransfTag 1; # associate a tag to column transformation
geomTransf Linear $ColTransfTag ;
# element connectivity:
set numIntgrPts 5; # number of integration points for force-based element
element nonlinearBeamColumn 1 1 2 $numIntgrPts $ColSecTag $ColTransfTag; # self-explanatory when using variables
# Define RECORDERS -------------------------------------------------------------
recorder Node -file Data/DFree.out -time -node 2 -dof 1 2 3 disp; # displacements of free nodes
recorder Node -file Data/DBase.out -time -node 1 -dof 1 2 3 disp; # displacements of support nodes
recorder Node -file Data/RBase.out -time -node 1 -dof 1 2 3 reaction; # support reaction
recorder Drift -file Data/Drift.out -time -iNode 1 -jNode 2 -dof 1 -perpDirn 2 ; # lateral drift
recorder Element -file Data/FCol.out -time -ele 2 globalForce; # element forces -- column
recorder Element -file Data/ForceColSec1.out -time -ele 1 section 1 force; # Column section forces, axial and moment, node i
recorder Element -file Data/DefoColSec1.out -time -ele 1 section 1 deformation; # section deformations, axial and curvature, node i
recorder Element -file Data/ForceColSec$numIntgrPts.out -time -ele 1 section $numIntgrPts force; # section forces, axial and moment, node j
recorder Element -file Data/DefoColSec$numIntgrPts.out -time -ele 1 section $numIntgrPts deformation; # section deformations, axial and curvature, node j
# define GRAVITY -------------------------------------------------------------
pattern Plain 1 Linear {
load 2 0 -$PCol 0
}
# Gravity-analysis parameters -- load-controlled static analysis
set Tol 1.0e-8; # 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
analyze $NstepGravity; # apply gravity
# ------------------------------------------------- maintain constant gravity loads and reset time to zero
loadConst -time 0.0
puts "Model Built"
# --------------------------------------------------------------------------------------------------
# Example4. 2D Portal Frame-- Static Reversed-Cyclic Analysis
# Silvia Mazzoni & Frank McKenna, 2006
# execute this file after you have built the model, and after you apply gravity
#
set LunitTXT "mm"
# we need to set up parameters that are particular to the model.
set IDctrlNode 2; # node where displacement is read for displacement control
set IDctrlDOF 1; # degree of freedom of displacement read for displacement contro
# characteristics of cyclic analysis
set iDmax "0.0046 0.0092 0.0147 0.0201 0.0311 0.0412 0.0522 "; # vector of displacement-cycle peaks, in terms of storey drift ratio
set Dincr 2.0; # displacement increment for pushover. you want this to be very small, but not too small to slow down the analysis
set Fact $LCol; # scale drift ratio by storey height for displacement cycles
set CycleType Full; # you can do Full / Push / Half cycles with the proc
set Ncycles 1; # specify the number of cycles at each peak
# create load pattern for lateral pushover load
set Hload [expr $Weight/2]; # define the lateral load as a proportion of the weight so that the pseudo time equals the lateral-load coefficient when using linear load pattern
set iPushNode 2; # define nodes where lateral load is applied in static lateral analysis
pattern Plain 200 Linear {; # define load pattern -- generalized
foreach PushNode $iPushNode {
load $PushNode $Hload 0.0 0.0 0.0 0.0 0.0
}
}
# ----------- set up analysis parameters
source LibAnalysisStaticParameters.tcl; # constraintsHandler,DOFnumberer,system-ofequations,convergenceTest,solutionAlgorithm,integrator
# --------------------------------- perform Static Cyclic Displacements Analysis
source LibGeneratePeaks.tcl
set fmt1 "%s Cyclic analysis: CtrlNode %.3i, dof %.1i, Disp=%.4f %s"; # format for screen/file output of DONE/PROBLEM analysis
foreach Dmax $iDmax {
set iDstep [GeneratePeaks $Dmax $Dincr $CycleType $Fact]; # this proc is defined above
for {set i 1} {$i <= $Ncycles} {incr i 1} {
set zeroD 0
set D0 0.0
foreach Dstep $iDstep {
set D1 $Dstep
set Dincr [expr $D1 - $D0]
integrator DisplacementControl $IDctrlNode $IDctrlDOF $Dincr
analysis Static
# ----------------------------------------------first analyze command------------------------
set ok [analyze 1]
# ----------------------------------------------if convergence failure-------------------------
if {$ok != 0} {
# if analysis fails, we try some other stuff
# performance is slower inside this loop global maxNumIterStatic; # max no. of iterations performed before "failure to converge" is ret'd
if {$ok != 0} {
puts "Trying Newton with Initial Tangent .."
test NormDispIncr $Tol 2000 0
algorithm Newton -initial
set ok [analyze 1]
test $testTypeStatic $TolStatic $maxNumIterStatic 0
algorithm $algorithmTypeStatic
}
if {$ok != 0} {
puts "Trying Broyden .."
algorithm Broyden 8
set ok [analyze 1 ]
algorithm $algorithmTypeStatic
}
if {$ok != 0} {
puts "Trying NewtonWithLineSearch .."
algorithm NewtonLineSearch 0.8
set ok [analyze 1]
algorithm $algorithmTypeStatic
}
if {$ok != 0} {
set putout [format $fmt1 "PROBLEM" $IDctrlNode $IDctrlDOF [nodeDisp $IDctrlNode $IDctrlDOF] $LunitTXT]
puts $putout
return -1
}; # end if
}; # end if
# -----------------------------------------------------------------------------------------------------
set D0 $D1; # move to next step
}; # end Dstep
}; # end i
}; # end of iDmaxCycl
# -----------------------------------------------------------------------------------------------------
if {$ok != 0 } {
puts [format $fmt1 "PROBLEM" $IDctrlNode $IDctrlDOF [nodeDisp $IDctrlNode $IDctrlDOF] $LunitTXT]
} else {
puts [format $fmt1 "DONE" $IDctrlNode $IDctrlDOF [nodeDisp $IDctrlNode $IDctrlDOF] $LunitTXT]
}
This is my procedure, Thank you for help me
# units: mm, n, sec
wipe; # clear memory of all past model definitions
file mkdir Data; # create data directory
model BasicBuilder -ndm 2 -ndf 3; # Define the model builder, ndm=#dimension, ndf=#dofs
# define GEOMETRY -------------------------------------------------------------
set LCol 1092; # column length
set Weight 2462702.; # superstructure weight
# calculated parameters
set PCol $Weight; # nodal dead-load weight per column
set g 9800; # g.
set Mass [expr $PCol/$g]; # nodal mass
# calculated geometry parameters
set ACol 58533; # cross-sectional area
# nodal coordinates:
node 1 0 0; # node#, X, Y
node 2 0 $LCol
# Single point constraints -- Boundary Conditions
fix 1 1 1 1; # node DX DY RZ
# nodal masses:
mass 2 $Mass 1e-9 0.; # node#, Mx My Mz, Mass=Weight/g, neglect rotational inertia at nodes
# Define ELEMENTS & SECTIONS -------------------------------------------------------------
set ColSecTag 1; # assign a tag number to the column section
# define section geometry
# MATERIAL parameters -------------------------------------------------------------------
set IDconcU 1; # material ID tag -- unconfined cover concrete
set IDreinf 2; # material ID tag -- reinforcement
# nominal concrete compressive strength
set fc -132.86; # CONCRETE Compressive Strength (+Tension, -Compression)
set Ec 40000.; # Concrete Elastic Modulus (the term in sqr root needs to be in psi
# unconfined concrete
set fc1U $fc; # UNCONFINED concrete (todeschini parabolic model), maximum stress
set eps1U -0.0137; # strain at maximum strength of unconfined concrete
set fc2U [expr 0.2*$fc1U]; # ultimate stress
set eps2U -0.05; # strain at ultimate stress
set lambda 0.1; # ratio between unloading slope at $eps2 and initial slope $Ec
# tensile-strength properties
set ftU 13.2; # tensile strength +tension
set Ets [expr $ftU/0.002]; # tension softening stiffness
# -----------
set Fy 372.; # STEEL yield stress
set Es 210000.; # modulus of steel
set Bs 0.01; # strain-hardening ratio
set R0 10; # 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 $IDconcU $fc1U $eps1U $fc2U $eps2U $lambda $ftU $Ets; # build cover concrete (unconfined)
uniaxialMaterial Steel02 $IDreinf $Fy $Es $Bs $R0 $cR1 $cR2; # build reinforcement material
section fiberSec $ColSecTag {; # Define the fiber section
patch circ $IDconcU 8 8 0.0 0.0 0.0 155.6 0.0 360.0; # Define the concrete patch
patch circ $IDreinf 8 8 0.0 0.0 130.0 162.0 0.0 360.0;
}; # end of fibersection definition
# define geometric transformation: performs a linear geometric transformation of beam stiffness and resisting force from the basic system to the global-coordinate system
set ColTransfTag 1; # associate a tag to column transformation
geomTransf Linear $ColTransfTag ;
# element connectivity:
set numIntgrPts 5; # number of integration points for force-based element
element nonlinearBeamColumn 1 1 2 $numIntgrPts $ColSecTag $ColTransfTag; # self-explanatory when using variables
# Define RECORDERS -------------------------------------------------------------
recorder Node -file Data/DFree.out -time -node 2 -dof 1 2 3 disp; # displacements of free nodes
recorder Node -file Data/DBase.out -time -node 1 -dof 1 2 3 disp; # displacements of support nodes
recorder Node -file Data/RBase.out -time -node 1 -dof 1 2 3 reaction; # support reaction
recorder Drift -file Data/Drift.out -time -iNode 1 -jNode 2 -dof 1 -perpDirn 2 ; # lateral drift
recorder Element -file Data/FCol.out -time -ele 2 globalForce; # element forces -- column
recorder Element -file Data/ForceColSec1.out -time -ele 1 section 1 force; # Column section forces, axial and moment, node i
recorder Element -file Data/DefoColSec1.out -time -ele 1 section 1 deformation; # section deformations, axial and curvature, node i
recorder Element -file Data/ForceColSec$numIntgrPts.out -time -ele 1 section $numIntgrPts force; # section forces, axial and moment, node j
recorder Element -file Data/DefoColSec$numIntgrPts.out -time -ele 1 section $numIntgrPts deformation; # section deformations, axial and curvature, node j
# define GRAVITY -------------------------------------------------------------
pattern Plain 1 Linear {
load 2 0 -$PCol 0
}
# Gravity-analysis parameters -- load-controlled static analysis
set Tol 1.0e-8; # 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
analyze $NstepGravity; # apply gravity
# ------------------------------------------------- maintain constant gravity loads and reset time to zero
loadConst -time 0.0
puts "Model Built"
# --------------------------------------------------------------------------------------------------
# Example4. 2D Portal Frame-- Static Reversed-Cyclic Analysis
# Silvia Mazzoni & Frank McKenna, 2006
# execute this file after you have built the model, and after you apply gravity
#
set LunitTXT "mm"
# we need to set up parameters that are particular to the model.
set IDctrlNode 2; # node where displacement is read for displacement control
set IDctrlDOF 1; # degree of freedom of displacement read for displacement contro
# characteristics of cyclic analysis
set iDmax "0.0046 0.0092 0.0147 0.0201 0.0311 0.0412 0.0522 "; # vector of displacement-cycle peaks, in terms of storey drift ratio
set Dincr 2.0; # displacement increment for pushover. you want this to be very small, but not too small to slow down the analysis
set Fact $LCol; # scale drift ratio by storey height for displacement cycles
set CycleType Full; # you can do Full / Push / Half cycles with the proc
set Ncycles 1; # specify the number of cycles at each peak
# create load pattern for lateral pushover load
set Hload [expr $Weight/2]; # define the lateral load as a proportion of the weight so that the pseudo time equals the lateral-load coefficient when using linear load pattern
set iPushNode 2; # define nodes where lateral load is applied in static lateral analysis
pattern Plain 200 Linear {; # define load pattern -- generalized
foreach PushNode $iPushNode {
load $PushNode $Hload 0.0 0.0 0.0 0.0 0.0
}
}
# ----------- set up analysis parameters
source LibAnalysisStaticParameters.tcl; # constraintsHandler,DOFnumberer,system-ofequations,convergenceTest,solutionAlgorithm,integrator
# --------------------------------- perform Static Cyclic Displacements Analysis
source LibGeneratePeaks.tcl
set fmt1 "%s Cyclic analysis: CtrlNode %.3i, dof %.1i, Disp=%.4f %s"; # format for screen/file output of DONE/PROBLEM analysis
foreach Dmax $iDmax {
set iDstep [GeneratePeaks $Dmax $Dincr $CycleType $Fact]; # this proc is defined above
for {set i 1} {$i <= $Ncycles} {incr i 1} {
set zeroD 0
set D0 0.0
foreach Dstep $iDstep {
set D1 $Dstep
set Dincr [expr $D1 - $D0]
integrator DisplacementControl $IDctrlNode $IDctrlDOF $Dincr
analysis Static
# ----------------------------------------------first analyze command------------------------
set ok [analyze 1]
# ----------------------------------------------if convergence failure-------------------------
if {$ok != 0} {
# if analysis fails, we try some other stuff
# performance is slower inside this loop global maxNumIterStatic; # max no. of iterations performed before "failure to converge" is ret'd
if {$ok != 0} {
puts "Trying Newton with Initial Tangent .."
test NormDispIncr $Tol 2000 0
algorithm Newton -initial
set ok [analyze 1]
test $testTypeStatic $TolStatic $maxNumIterStatic 0
algorithm $algorithmTypeStatic
}
if {$ok != 0} {
puts "Trying Broyden .."
algorithm Broyden 8
set ok [analyze 1 ]
algorithm $algorithmTypeStatic
}
if {$ok != 0} {
puts "Trying NewtonWithLineSearch .."
algorithm NewtonLineSearch 0.8
set ok [analyze 1]
algorithm $algorithmTypeStatic
}
if {$ok != 0} {
set putout [format $fmt1 "PROBLEM" $IDctrlNode $IDctrlDOF [nodeDisp $IDctrlNode $IDctrlDOF] $LunitTXT]
puts $putout
return -1
}; # end if
}; # end if
# -----------------------------------------------------------------------------------------------------
set D0 $D1; # move to next step
}; # end Dstep
}; # end i
}; # end of iDmaxCycl
# -----------------------------------------------------------------------------------------------------
if {$ok != 0 } {
puts [format $fmt1 "PROBLEM" $IDctrlNode $IDctrlDOF [nodeDisp $IDctrlNode $IDctrlDOF] $LunitTXT]
} else {
puts [format $fmt1 "DONE" $IDctrlNode $IDctrlDOF [nodeDisp $IDctrlNode $IDctrlDOF] $LunitTXT]
}