ZeroLength Element Recorder

[wuhaoshrek]

Dear All,

I understand that the recorder for zerolength element should be the same as others. When I use zerolength element
with section, i.e., ZeroLengthSection Element, I wanna recorder the stressStrain history of the fibers of the section,
however I found no output in the end of the running. My recorder commander example is as follows:

recorder Element -file $dataDir/B4_SS4.out -time -ele 1 section 1 fiber [expr -0.375*$m] 0 $IDMATSS_MinMax4 stress;

Anybody knows why the output is blank? Many thanks.

[vesna]

try this:

eval "recorder Element -file $dataDir/B4_SS4.out -time -ele 1 section 1 fiber [expr -0.375*$m] 0 $IDMATSS_MinMax4 stress"

[wuhaoshrek]

vesna wrote:
> try this:
>
> eval "recorder Element -file $dataDir/B4_SS4.out -time -ele 1 section
> 1 fiber [expr -0.375*$m] 0 $IDMATSS_MinMax4 stress"

Vesna,
Still comes out nothing, just one column of time, and I checked fiber location, mat number
are all right.

[vesna]

Can you make a simple example with only zeroLenghtSection element to demonstrate the problem, so I can look at it.

[wuhaoshrek]

vesna wrote:
> Can you make a simple example with only zeroLenghtSection element to
> demonstrate the problem, so I can look at it.

Thanks vesna.

My model is quite simple, initially I just wanna verify the MinMax material. Below is
my model:
=====================================================
wipe ;
model basic -ndm 2 -ndf 3 ;
set dataDir Output_MinMax ;
file mkdir $dataDir ;

node 1 0. 0.;
node 2 0. 0.;

set Fy1 [expr 20.44E8];
set E01 [expr 32.0E11];
set b1 0.01;

set Fy2 [expr 20.44E8];
set E02 [expr 32.0E11];
set b2 0.01;

set Fy3 [expr 20.44E8];
set E03 [expr 32.0E11];
set b3 0.01;

set Fy4 [expr 20.44E8];
set E04 [expr 32.0E11];
set b4 0.01;


uniaxialMaterial Steel01 1 $Fy1 $E01 $b1;
uniaxialMaterial Steel01 2 $Fy2 $E02 $b2;
uniaxialMaterial Steel01 3 $Fy3 $E03 $b3;
uniaxialMaterial Steel01 4 $Fy4 $E04 $b4;

set IDMATSS_MinMax1 11;
uniaxialMaterial MinMax $IDMATSS_MinMax1 1 -max 6.39E-3; # -min -6.39E-3

set IDMATSS_MinMax2 12;
uniaxialMaterial MinMax $IDMATSS_MinMax2 2 -max 6.39E-3; # -min -6.39E-3

set IDMATSS_MinMax3 13;
uniaxialMaterial MinMax $IDMATSS_MinMax3 3 -max 6.39E-3; # -min -6.39E-3

set IDMATSS_MinMax4 14;
uniaxialMaterial MinMax $IDMATSS_MinMax4 4 -max 6.39E-3; # -min -6.39E-3

section fiberSec 1 {

fiber [expr 0.375] 0 [expr 0.25] $IDMATSS_MinMax1 ;
fiber [expr 0.125] 0 [expr 0.25] $IDMATSS_MinMax2 ;
fiber [expr -0.125] 0 [expr 0.25] $IDMATSS_MinMax3 ;
fiber [expr -0.375] 0 [expr 0.25] $IDMATSS_MinMax4 ;

};

element zeroLengthSection 1 1 2 1 -orient 0 1 0 -1 0 0 ;

fix 1 1 1 1 ;
fix 2 1 0 0 ;

recorder Node -file $dataDir/A1_Node_Disp_2_1.out -time -node 2 -dof 1 2 3 disp ;
recorder Node -file $dataDir/A2_Node_React_1.out -time -node 1 -dof 1 2 3 reaction ;

recorder Element -file $dataDir/B1_SS4.out -time -ele 1 section 1 fiber [expr -0.375] 0 $IDMATSS_MinMax3 stress

eval "recorder Element -file $dataDir/B2_SS4.out -time -ele 1 section 1 fiber [expr -0.375] 0 $IDMATSS_MinMax3 stress";


set IDctrlNode 2;
set IDctrlDOF 3;

set TargetDisp [expr 0.06];
set Dincr [expr 0.001];

timeSeries Linear 1 -factor 1.0; # lambda=factor*t

pattern Plain 1 1 {
load $IDctrlNode 0.0 0.0 -1.0;
}

numberer RCM;
system BandGeneral;
constraints Plain;
test NormDispIncr 1.e-8 20 2;
algorithm Newton; # Options: Newton, NewtonLineSearch, ModifiedNewton, KrylovNewton
integrator DisplacementControl $IDctrlNode $IDctrlDOF $Dincr;
analysis Static;

# perform static monotonic pushover analysis
set currentDisp [nodeDisp $IDctrlNode $IDctrlDOF];

while {$currentDisp<$TargetDisp} {

set ok [analyze 1];
set currentDisp [nodeDisp $IDctrlNode $IDctrlDOF];

}

puts "-------------------------------------"
puts "Monotonic Pushover Analysis Finished."
puts "-------------------------------------"
=====================================================

Thank you very much.

[Pablongo]

I'm having the exact same problem. Please reply if you can solve it.

[Pablongo]

Let me clarify, I am getting a recorded output. Judging by the numbers recorded, it seems to be stress. But I can't record the strain (or anything else) along with the stress values. I need the strain values.

[wuhaoshrek]

Pablongo wrote:
> Let me clarify, I am getting a recorded output. Judging by the numbers
> recorded, it seems to be stress. But I can't record the strain (or anything
> else) along with the stress values. I need the strain values.

Is your output file with only one column? is it time series? could you please
post your recorder command here.

[Pablongo]

Yes, my output file is only one column. I did a cyclic pushover analysis and plotted this output against displacement at the node of interest. The curve seems to indicate that the output I'm getting is stress. My recorder command is shown below. However, I tried the same "recorder Element -file $dataDir/ConcS.out -time -ele $elenum..." followed by different arguments (stress, strain, force, etc...) and regardless of the arguments I always got the same output.

recorder Element -file $dataDir/ConcS.out -time -ele $elenum fiber $y $z $matTag stressStrain;

[wuhaoshrek]

Pablongo wrote:
> Yes, my output file is only one column. I did a cyclic pushover analysis
> and plotted this output against displacement at the node of interest. The
> curve seems to indicate that the output I'm getting is stress. My recorder
> command is shown below. However, I tried the same "recorder Element
> -file $dataDir/ConcS.out -time -ele $elenum..." followed by different
> arguments (stress, strain, force, etc...) and regardless of the arguments I
> always got the same output.
>
> recorder Element -file $dataDir/ConcS.out -time -ele $elenum fiber $y $z
> $matTag stressStrain;

The only one column value is time.

[Pablongo]

Yes, you're right. I checked again, and it is only time.

Vesna, or Frank, have you been able to look at this issue?

[vesna]

I was sick for the week and was not able to check on this earlier.

For some reason it does not take the coordinates of the fibers but fiber numbers.

This one works:
recorder Element -xml $dataDir/B2_SS4.out -time -ele 1 section 1 fiber 1 stress;

I saved it into xml format so you can see the coordinates of the fiber.

[wuhaoshrek]

vesna wrote:
> I was sick for the week and was not able to check on this earlier.
>
> For some reason it does not take the coordinates of the fibers but fiber
> numbers.
>
> This one works:
> recorder Element -xml $dataDir/B2_SS4.out -time -ele 1 section 1 fiber 1
> stress;
>
> I saved it into xml format so you can see the coordinates of the fiber.

YES, vesna, with fiber number it works and the coords could be find with xml- file.

Thanks very much, hopefully you would be better soon.

Best.

Hao