quasi static loading

[peacemaker]

hi, everybody.
I'm modeling a flag-shape behavior on a simple element using TwoNodeLink element. I tested the model with Sine form dynamic loading and everything was OK.
at the moment i'm trying to apply a "quasi-static loading" though i need to verify my model with an experimental results. I checked my model 3 times! As everything was happy with Sine form dynamic loading, i guess the problem is with my defined timeSeries. when i run the model on opensees , the program will be terminated.I need to say that i applied the -disp type groundMotion by ImposedMotionSP command.
i would be grateful if u could give me some advises.

Here is the model :

# modeling of flag-shape material
# units :kgf,cm,sec
# #############################

wipe;
model BasicBuilder -ndm 2 -ndf 3;

set Lcol 300;
set x1 0.00;
set y1 0.00;
set x2 [expr $x1+$Lcol];
set y2 0.00;

# |----------------------0| <--->P(x)-Loading [ horizontal column with the length of 3m]


# ##############################
node 1 $x1 $y1;
node 2 $x2 $y2;
# ##############################
fix 1 1 1 1;
fix 2 0 1 1;
mass 2 300 0.0 0.0;
# ##############################
set matID_eml 1; # Elastic Multi Linear Material Tag
set matID_ml 2; # Multi Linear Material Tag
set matID_pll 3; # Parallel Material Tag

set eleID_brace 1; # Brace Element Tag
uniaxialMaterial ElasticMultiLinear $matID_eml -strain -6 -1 0.0 1 6 -stress -110e3 -100e3 0.0 100e3 110e3;
uniaxialMaterial MultiLinear $matID_ml 0.25 50000 6 50001;
uniaxialMaterial Parallel $matID_pll $matID_eml $matID_ml;
element twoNodeLink $eleID_brace 1 2 -mat $matID_pll -dir 1;

puts "model buit . ."

# ##################################
recorder Node -file disp2.out -xml disp2.xml -time -node 2 -dof 1 disp;
recorder Node -file force1.out -xml force2.xml -time -node 1 -dof 1 reaction;
# ##################################

set QuasiStaticLoadingID 10;
set QuasiStaticGMID 20;
set QuasiStaticPatternID 30;
set GMdirection 1;

#
timeSeries Path $QuasiStaticLoadingID -fileTime tquasi.txt -filePath vquasi.txt ;
#quasi static times :{0 1 2 3 4 5 6 ................................................ 30} sec
#quasi static values :{0 3 6 9 12 15 12 9 6 3 0 3 0 3 6 3 0 3 6 9 6 3 0 3 6 9 12 9 6 3 0}

pattern MultipleSupport $QuasiStaticPatternID {
groundMotion $QuasiStaticGMID Plain -disp $QuasiStaticLoadingID;
imposedMotion 2 $GMdirection $QuasiStaticGMID;
}

set sec 1;
set DtAnalysis [expr 0.01*$sec];
set TmaxAnalysis [expr 30. *$sec];
source LibAnalysisDynamicParameters.tcl;

set Nsteps [expr int($TmaxAnalysis/$DtAnalysis)];
set ok [analyze $Nsteps $DtAnalysis];

puts "Quasi-Static Loading Done! End Time: [getTime]"

[peacemaker]

till vesna or frank come to help me ! I've done some small modification on my model , first of all, when i apply the imposedMotion command on node 2 , opensees will not be terminated and analysis will perform as usual , but the results don't make any sense . a "wave shape" force-displacement will come out.
is there anyone else had a similar problem on loading -disp timeseries on a model ?

[peacemaker]

another test i've done is that when i apply a Sine form dynamic loading in -accel mode using UniformExitaton , everything is ok , when i change it to -disp mode [ with required modification] using MultipleSupport and imposedMotion command the responses will not make any sense, frank could u plz give some helps ?

[peacemaker]

Dear Frank / vesna
I set a displacement history file ( a time series of displacements ) and changed the load pattern to use the sp command :
disp history =exp(0.05t)sin(2PI/T)t, t=0.0~30 sec . dt=o.o1

and i run a loadcontrol static analysis , i applied the sp command to the un-fixed node .
approximately every thing is ok now , but i have a problem with my hysteresis response , the shape and disp values sounds good , but forces values are not symmetrical now! in one side it perform full recentering , but in the other sidee of response curve , the force level is approximately 0.2 of first side !

if u have time ! i would be really thankful , if u could check my model .
here is the revised model :


# modeling of flag-shape material
# units :kgf,cm,sec
# #############################
wipe;
model BasicBuilder -ndm 2 -ndf 3;

set Lcol 300;
set x1 0.00;
set y1 0.00;
set x2 [expr $x1+$Lcol];
set y2 0.00;
# |1----------------------2| <--->P(x)-Loading


# ##############################
node 1 $x1 $y1;
node 2 $x2 $y2;
# ##############################
fix 1 1 1 1;
fix 2 0 1 1;
#mass 2 300 0.0 0.0;
# ##############################
set matID_eml 1; # Elastic Multi Linear Material Tag
set matID_ml 2; # Multi Linear Material Tag
set matID_pll 3; # Parallel Material Tag


set eleID_brace 1; # Brace Element Tag
uniaxialMaterial ElasticMultiLinear $matID_eml -strain -5 -0.2 0.0 0.2 5 -stress -140000 -100000 0.0 100000 140000;
uniaxialMaterial MultiLinear $matID_ml 0.01 50000 4 50001 6 50002;
uniaxialMaterial Parallel $matID_pll $matID_eml $matID_ml;
element twoNodeLink $eleID_brace 1 2 -mat $matID_pll -dir 1;

puts "model buit . ."

# ##################################
recorder Node -file disp2.out -xml disp2.xml -time -node 2 -dof 1 disp;
recorder Node -file force1.out -xml force2.xml -time -node 1 -dof 1 reaction;
# ##################################


set QuasiStaticPatternID 30;


set IDCtrlNode 2;

set GMdirection 1;
set dofValue 1.0;
set dt 0.01;

set dispHistory "Series -dt $dt -filePath dispHistory.txt"
pattern Plain $QuasiStaticPatternID $dispHistory {
sp $IDCtrlNode $GMdirection $dofValue
};
constraints Penalty 1e15 1e15
numberer RCM
system FullGeneral
test EnergyIncr 1.e-8 50 0
algorithm Newton
integrator LoadControl $dt
analysis Static
set ok [analyze 3000]

puts "::: yooo hooo :::"