dispBeamColumn and Element recorder

[saeedeh]

hello
I have 2 question and I will really appreciate it if you help.

1. I modeled a concrete cantilever beam with dispBeamColumn element, when I use element recorder like this:

recorder Element -file out/momentf.txt -ele 1 section 1 force
recorder Element -file out/momentd.txt -ele 1 section 1 deformation

it doesn't record anything (empty text file), but when I change it to "section 3" it will give me some results, what's the problem with " section 1 & 2"? (its fiber section)

2. I use DisplacementControl integrator for my cyclic load, but when I record the results the displacement goes further than what I entered, how its possible?

[fmk]

can you post a little 1 element model with the commands you are using.

[saeedeh]

thank you very much
now my second problem about displacement solved, but any comment about any point in the script will be great.

here you are

wipe all
model basic -ndm 2 -ndf 3

#units are kg and cm

#costant parameters

set pi 3.1415
set b 20
set h 20
set cover 2.5
set bu [expr $b/2]
set bc [expr $b/2-$cover]
set fi_t 1.137
set fi_b 1.2
set Areafi_t [expr $pi*$fi_t*$fi_t/4]
set Areafi_b [expr $pi*$fi_b*$fi_b/4]
set fi_nt 3
set fi_nb 4
set L 125.
set fc_uncf -260.
set fu_uncf 0
set fy 4120
set fu 6120.
set epsy_bar 0.002
set epsu_bar 0.18
set Es [expr $fy/$epsy_bar]
set epsc0_uncf -0.002
set epsU_uncf -0.005
set Ec [expr 15100*pow((-1*$fc_uncf),0.5)]
set axialLoad -125

set iteration 10000
set persicion 1.0e-5

#materials
uniaxialMaterial Concrete01 1 $fc_uncf $epsc0_uncf $fu_uncf $epsU_uncf
uniaxialMaterial Steel02 3 $fy $Es 0.01 10 0.925 0.15

#fiber section
section fiberSec 1 {

#concrete fiber
patch quad 1 10 10 [expr -$bc] [expr -$bc] [expr +$bc] [expr -$bc] [expr +$bc] [expr +$bc] [expr -$bc] [expr +$bc]
patch quad 1 10 2 [expr -$bu] [expr -$bu] [expr +$bu] [expr -$bu] [expr +$bu] [expr -$bc] [expr -$bu] [expr -$bc]
patch quad 1 10 2 [expr -$bu] [expr +$bc] [expr +$bu] [expr +$bc] [expr +$bu] [expr +$bu] [expr -$bu] [expr +$bu]
patch quad 1 2 6 [expr -$bu] [expr -$bc] [expr -$bc] [expr -$bc] [expr -$bc] [expr +$bc] [expr -$bu] [expr +$bc]
patch quad 1 2 6 [expr +$bc] [expr -$bc] [expr +$bu] [expr -$bc] [expr +$bu] [expr +$bc] [expr +$bc] [expr +$bc]

#reinforcement fiber
layer straight 3 $fi_nt $Areafi_t [expr +$bc] [expr -$bc] [expr +$bc] [expr +$bc]
layer straight 3 $fi_nb $Areafi_b [expr -$bc] [expr -$bc] [expr -$bc] [expr +$bc]
}

#define nodes
node 1 0 0
node 2 0 [expr $L/5]
node 3 0 [expr $L*2/5]
node 4 0 [expr $L*3/5]
node 5 0 [expr $L*4/5]
node 6 0 $L

set basenode 1
set topnode 6
set dof_rec 1


set lintag 1
geomTransf PDelta $lintag


#define elements
element dispBeamColumn 1 1 2 5 1 $lintag
element dispBeamColumn 2 2 3 5 1 $lintag
element dispBeamColumn 3 3 4 5 1 $lintag
element dispBeamColumn 4 4 5 5 1 $lintag
element dispBeamColumn 5 5 6 5 1 $lintag

#constraint

fix 1 1 1 1

#display

recorder display Frame 10 10 500 500 -wipe
vup 0 1 0
prp 0 0 1000000
display 1 1 1


#axial load analyse

integrator LoadControl 0 1 0 0
system ProfileSPD
constraints Plain
test NormDispIncr $persicion $iteration
algorithm Newton
numberer RCM

analysis Static
pattern Plain 2 "Constant" {
load $topnode 0 $axialLoad 0
}
analyze 1
wipeAnalysis


#cyclic load and recorders

file mkdir out

set Dincr [list 0.016 -0.032 0.032 -0.032 0.056 -0.08 0.08 -0.08 0.12 -0.16 0.16 -0.16 0.24 -0.32 0.32 -0.32 0.32 -0.32 0.48 -0.64 0.64 -0.64 0.64 -0.64 0.8 -0.96 0.96 -0.96 0.96 -0.96 1.12 -1.28 1.28 -1.28 1.28 -1.28 1.44 -1.6 1.6]

recorder Node -file out/Displacement.txt -node $topnode -dof $dof_rec disp
recorder Node -file out/Force.txt -node $basenode -dof $dof_rec reaction

recorder Element -file out/momentf.txt -ele 1 section 1 force
recorder Element -file out/momentd.txt -ele 1 section 1 deformation

recorder Element -file out/stresstrain.txt -ele 1 section 1 fiber 10 10 stressStrain


recorder Node -file out/axialforcet.txt -node $topnode -dof 2 reaction
recorder Node -file out/axialforceb.txt -node $basenode -dof 2 reaction



#cyclic load analyze

system ProfileSPD
constraints Plain
test NormDispIncr $persicion $iteration
algorithm Newton -initial
numberer RCM
pattern Plain 1 "Linear" {
load $topnode 1 0 0
}

for {set j 0} {$j < [llength $Dincr]} {incr j 1} {
puts "total steps = Analyze $j out of [llength $Dincr]"

integrator DisplacementControl $topnode $dof_rec [lindex $Dincr $j]
analysis Static
set Nstep 10
analyze $Nstep
}