Who can tell me what is wrong with this model?!!!!!

[sharareh]

Dear all, (especially Silvia) I've used elastic sections and performed static analysis first but the behavior is totally elastic. Can you take a look on my script to see whetherthere is something wrong or not. It would be so helpful for me.

Here it is:
# 3 storey building with 3 bays in x-direction and 2 bays in y-direction
# the bay length is 5 m in all directions, storey height is 3 m.
#
#
#--------------------------------------------------------------------------------
# nonlinear beam-column elements
# nonlinear dynamic analysis
#--------------------------------------------------------------------------------
# Units: kgf, m, sec
#
# Written: Sharareh Javadian
# Date: 2005

wipe;

#********************************************************************************
# Start of model Generation
#********************************************************************************

# Create ModelBuilder (with three- dimensions and 6 DOF/node)

model BasicBuilder -ndm 3 -ndf 6

#--------------------------------------------------------------
# Parameter Identifying
#--------------------------------------------------------------

# The number of bays in x-direction

set numBayx 3

# The number of bays in y-direction

set numBayy 2

# The number of stories is 3

set story 3

#--------------------------------------------------------------
# Create Nodes
#--------------------------------------------------------------

# Set parameters for overall model geometry

set bayWidth 5
set stHeight 3
set nodeID 1
set i 0
set k 0
set j 0

# Define nodes

for {set i 0} {$i<=$numBayy} {incr i 1} {
for {set k 0} {$k<=$story} {incr k 1} {
for {set j 0} {$j<=$numBayx} {incr j 1} {
set yDim [expr $i*$bayWidth]
set xDim [expr $j*$bayWidth]

# tag x y z

node $nodeID $xDim $yDim [expr $k*$stHeight]

incr nodeID 1
}
set j 0
}
set k 0
}

#----------------------------
#Define master nodes
#----------------------------

# tag x y z

node 49 7.5 5 3
node 50 7.5 5 6
node 51 7.5 5 9

#---------------------------------------------------------------
#Define boundary condition,Fixed supports at base of columns
#---------------------------------------------------------------

set i 0
set j 0

for {set i 0} {$i<=$numBayy} {incr i 1} {
for {set j 0} {$j<=$numBayx} {incr j 1} {
# Node Dx Dy Dz Rx Ry Rz
fix [expr $j+1+16*$i] 1 1 1 1 1 1
}
set j 0
}
fix 49 0 0 1 1 1 0
fix 50 0 0 1 1 1 0
fix 51 0 0 1 1 1 0

#**********************************************************************************
# Section Definition
#**********************************************************************************

set E [expr 2.039*pow(10,10)]
set G [expr 7.842*pow(10,9)]
#TUBO260x10
set A3 [expr 1.0*pow(10,-2)]
set Iy3 [expr 1.043*pow(10,-4)]
set Iz3 [expr 1.043*pow(10,-4)]
set J3 [expr $Iy3+$Iz3]
#IPE270
set A1 [expr 4.59*pow(10,-3)]
set Iy1 [expr 4.2*pow(10,-6)]
set Iz1 [expr 5.79*pow(10,-5)]
set J1 [expr $Iy1+$Iz1]
#IPE330
set A2 [expr 6.26*pow(10,-3)]
set Iy2 [expr 7.88*pow(10,-6)]
set Iz2 [expr 1.177*pow(10,-4)]
set J2 [expr $Iy2+$Iz2]

#IPE270
section Elastic 1 $E $A1 $Iz1 $Iy1 $G $J1
#IPE330
section Elastic 2 $E $A2 $Iz2 $Iy2 $G $J2
#TUBO260x10
section Elastic 3 $E $A3 $Iz3 $Iy3 $G $J3

#-------------------------------------------------------------------
# Coordinate transformation for columns
#-------------------------------------------------------------------

geomTransf Linear 1 1 0 1

#-------------------------------------------------------------------
# Coordinate transformation for beams
#-------------------------------------------------------------------

geomTransf Linear 2 1 1 0

#************************************************************************************
# Element Definition
#************************************************************************************

#-------------------------------------------------------------------
# Beams in X direction
#-------------------------------------------------------------------

set locTol [expr pow(10,-25)]
set i 1

for {set i 1} {$i<=$numBayx} {incr i 1} {

#element nonlinearBeamColumn $eleTag $iNode $jNode $IntP $sec $trf <-iter $maxIters $tol>

element nonlinearBeamColumn $i [expr $i+4] [expr $i+5] 10 1 2 -iter 10 $locTol
element nonlinearBeamColumn [expr $i+3] [expr $i+20] [expr $i+21] 10 1 2 -iter 10 $locTol
element nonlinearBeamColumn [expr $i+6] [expr $i+36] [expr $i+37] 10 1 2 -iter 10 $locTol
element nonlinearBeamColumn [expr $i+17] [expr $i+8] [expr $i+9] 10 1 2 -iter 10 $locTol
element nonlinearBeamColumn [expr $i+20] [expr $i+24] [expr $i+25] 10 1 2 -iter 10 $locTol
element nonlinearBeamColumn [expr $i+23] [expr $i+40] [expr $i+41] 10 1 2 -iter 10 $locTol
element nonlinearBeamColumn [expr $i+34] [expr $i+12] [expr $i+13] 10 1 2 -iter 10 $locTol
element nonlinearBeamColumn [expr $i+37] [expr $i+28] [expr $i+29] 10 1 2 -iter 10 $locTol
element nonlinearBeamColumn [expr $i+40] [expr $i+44] [expr $i+45] 10 1 2 -iter 10 $locTol
}

#-------------------------------------------------------------------------
# Beams in y direction
#-------------------------------------------------------------------------

set i 1

for {set i 1} {$i<=$numBayy} {incr i 1} {

#element nonlinearBeamColumn $eleTag $iNode $jNode $IntP $sec $trf <-iter $maxIters $tol>

element nonlinearBeamColumn [expr $i+9] [expr ($i-1)*16+5] [expr $i*16+5] 10 2 2 -iter 10 $locTol
element nonlinearBeamColumn [expr $i+11] [expr ($i-1)*16+6] [expr $i*16+6] 10 2 2 -iter 10 $locTol
element nonlinearBeamColumn [expr $i+13] [expr ($i-1)*16+7] [expr $i*16+7] 10 2 2 -iter 10 $locTol
element nonlinearBeamColumn [expr $i+15] [expr ($i-1)*16+8] [expr $i*16+8] 10 2 2 -iter 10 $locTol
element nonlinearBeamColumn [expr $i+26] [expr ($i-1)*16+9] [expr $i*16+9] 10 2 2 -iter 10 $locTol
element nonlinearBeamColumn [expr $i+28] [expr ($i-1)*16+10] [expr $i*16+10] 10 2 2 -iter 10 $locTol
element nonlinearBeamColumn [expr $i+30] [expr ($i-1)*16+11] [expr $i*16+11] 10 2 2 -iter 10 $locTol
element nonlinearBeamColumn [expr $i+32] [expr ($i-1)*16+12] [expr $i*16+12] 10 2 2 -iter 10 $locTol
element nonlinearBeamColumn [expr $i+43] [expr ($i-1)*16+13] [expr $i*16+13] 10 2 2 -iter 10 $locTol
element nonlinearBeamColumn [expr $i+45] [expr ($i-1)*16+14] [expr $i*16+14] 10 2 2 -iter 10 $locTol
element nonlinearBeamColumn [expr $i+47] [expr ($i-1)*16+15] [expr $i*16+15] 10 2 2 -iter 10 $locTol
element nonlinearBeamColumn [expr $i+49] [expr ($i-1)*16+16] [expr $i*16+16] 10 2 2 -iter 10 $locTol
}
#-----------------------------------------------------------------------
# columns
#-----------------------------------------------------------------------

set columnID 52

for {set j 0} {$j<=2} {incr j 1} {

for {set i 1} {$i<=12} {incr i 1} {

element nonlinearBeamColumn $columnID [expr $i+$j*16] [expr $i+16*$j+4] 10 3 1 -iter 10 $locTol

incr columnID 1
}
set i 1
}

#**************************************************************************************
# definition of rigid diaphragm
#**************************************************************************************

rigidDiaphragm 3 49 5 6 7 8 21 22 23 24 37 38 39 40
rigidDiaphragm 3 50 9 10 11 12 25 26 27 28 41 42 43 44
rigidDiaphragm 3 51 13 14 15 16 29 30 31 32 45 46 47 48

#***************************
# Set mass at master nodes
#***************************

set m1 8911
set I1 [expr $m1*27.083]
set m2 7849
set I2 [expr $m2*27.083]

# Tag Mx My Mz Rx Ry Rz

mass 49 $m1 $m1 0 0 0 $I1
mass 50 $m1 $m1 0 0 0 $I1
mass 51 $m2 $m2 0 0 0 $I2

#--------------------------------------
# Earthquake setup
#--------------------------------------

# Set up the acceleration records for Tabas

set tabas "Path -filePath tabas.txt -dt 0.02 -factor 0.587"
set elcentro "Path -filePath elcentro.txt -dt 0.02 -factor 14.04792"
#set northridge "Path -filePath northridge.txt -dt 0.02 -factor 1"

# Define the excitation using the Tabas ground motion records

# tag dir accel series args

#pattern UniformExcitation 1 1 -accel $tabas
pattern UniformExcitation 2 1 -accel $elcentro
#pattern UniformExcitation 4 2 -accel $elcentro
#pattern UniformExcitation 3 1 -accel $northridge

#***************************
# End of model generation
#***************************
#*********************************
# Start of Analysis generation
#*********************************
# Create the convergence test
# tol maxIter printFlag

test EnergyIncr 1.0e-8 20 5

# Create the solution algorithm

algorithm Newton

# Create the system of equation storage and solver

system SparseGeneral -piv

# Create the constraint handler

constraints Transformation

# Create the time integration scheme

# gamma beta

integrator Newmark 0.5 0.25

# Create the DOF numberer

numberer RCM

# Damping definition

#rayleigh $alphaM $betaK $betaKinit $betaKcomm

rayleigh 0.1854 0 0 0.00215

# Create the transient analysis

analysis Transient

# --------------------------
# End of analysis generation
# --------------------------
# ----------------------------
# Start of recorder generation
# ----------------------------

# Record DOF 1 and 2 displacements at nodes 51 and 52, 53

recorder Node -file nodeDISP.out -time -node 51 -dof 1 2 6 disp
recorder Node -file nodeVEL.out -time -node 51 -dof 1 2 6 vel
recorder Node -file nodeACC.out -time -node 51 -dof 1 2 6 accel

# --------------------------
# End of recorder generation
# --------------------------
# --------------------
# Perform the analysis
# --------------------
# Analysis duration of 70 seconds
# numSteps dt
analyze 7000 0.01

[silvia]

are you having problems with it?

[sharareh]

Yes. Of course. As I said it doesn't show nonlinear behavior! Evenif I set the earthquake factor a large number like 500!!!!! It continues to behave elastically untill it collapses.

[Rocky]

And the reason may be the definition of :

#IPE270
section Elastic 1 $E $A1 $Iz1 $Iy1 $G $J1
#IPE330
section Elastic 2 $E $A2 $Iz2 $Iy2 $G $J2
#TUBO260x10
section Elastic 3 $E $A3 $Iz3 $Iy3 $G $J3


I didnot do the analysis, but I cannot found where you define nonlinearity.

[ekalkan]

The problem is you dont have nonlinear material model, thats why you are getting elastic results.