Simulation of a cyclic test on a column

[andrett7]

Dear all,

sorry for my question. I want to simulate an experimental test on a simple cantilever column, where there is a history of imposed displacement on the top. I have a file with this history.

Which is the best way to simulate it? Should I use a cyclic pushover in displacement control or sp command in load control?

Thanks

[silvia]

if you look at the examples manual, what i do for the cyclic loading is create a list of displacement increments and then apply them.
i think the easiest thing for you to do is replace that list with a new list of displacement increments that you can calculate from your displacement history.

[andrett7]

Thanks Silvia, i'll try

[silvia]

dicche'!

[andrett7]

Dear Silvia,
thanks for your suggestions. I attach here your file modified considering my history displacement if someoe is interested.


# --------------------------------------------------------------------------------------------------
# Static Reversed-Cyclic Analysis
#
# execute this file after you have built the model, and after you apply gravity
#

# 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
# specify the number of cycles at each peak

set filename "DispHist.out"
set dispID [open $filename r]; #Load the vector with the history of displacement
set disp_hist [read $dispID]
close $dispID

set lengthDisp [llength $disp_hist]
set Dincr 0.001;

# create load pattern for lateral pushover load
set Hload $AxialForce; # 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
load $IDctrlNode $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
set fmt1 "%s Cyclic analysis: CtrlNode %.3i, dof %.1i, Disp=%.4f %s"; # format for screen/file output of DONE/PROBLEM analysis
set zeroD 0
set D0 0.0
foreach Dstep $disp_hist {
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

# -----------------------------------------------------------------------------------------------------
if {$ok != 0 } {
puts [format $fmt1 "PROBLEM" $IDctrlNode $IDctrlDOF [nodeDisp $IDctrlNode $IDctrlDOF] $LunitTXT]
} else {
puts [format $fmt1 "DONE" $IDctrlNode $IDctrlDOF [nodeDisp $IDctrlNode $IDctrlDOF] $LunitTXT]
}

[silvia]

i'm guessing it worked?

[andrett7]

Yes Silvia it works...thanks

[amirkochek]

andrett7 wrote:
> Yes Silvia it works...thanks
Dear andrett7,
I am a beginner and it seems that I am in a same condition you had been for last year. I am a PhD student and for my thesis I am trying to use Peer column data base as reference. So, I need to use displacement part of hysteresis model for loading of columns. I would be grateful if you could let me know how I can consider this issue.

[jayghosh]

Hi Andrette, glad to see this post and thanks for posting your code. Could you please tell me where can i get the experimental data for this test? Thanks!