WARNING BandGenLinLapackSolver::solve() -LAPACK routine

[anicknam]

Hello,

I am pretty new to Opensees and am trying to model a seismic-force resisting system (called PRW) which consists of an unbonded post-tensioned (PT) concrete wall (with rocking behavior at the base) and two Buckling-Restrained Braces (BRB) diagonally attached to the wall (at a point around mid-height of the wall) on each side. Here is a summary of the elements I used in the model:

1) Wall: dispBeamColumnInt
2) BRBs: corotTruss
3) Rigid Elements (corotTruss) for:
- Connecting the Wall/Foundation and BRB/Foundation connection points. (like a base plate)
- The Wall/BRB attachment.
- BRB/Foundation Attachment.
- Top and bottom of the wall (Top: for having same lateral disp. between PT bars and the Wall and Bottom: to represent wall toes which are expected to uplift)
4) Zero-length elements for Wall uplift and Base Rotational Spring that account for the foundation compliance.

I am trying to run an eigen-value analysis through the model to check the fundamental period and as the first trial I fixed all nodes representing the base plate and wall base and also rotational spring and therefore the wall is expected to respond as a conventional shear wall and there is no compliance in the foundation (foundation is fixed). HOWEVER, I get the following error when I run the eigen value analysis:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
WARNING BandGenLinLapackSolver::solve() -LAPACK routine returned 51
WARNING BandGenLinLapackSolver::solve() -LAPACK routine returned 51
WARNING BandGenLinLapackSolver::solve() -LAPACK routine returned 51
WARNING BandGenLinLapackSolver::solve() -LAPACK routine returned 51
WARNING BandGenLinLapackSolver::solve() -LAPACK routine returned 51
WARNING BandGenLinLapackSolver::solve() -LAPACK routine returned 51
WARNING BandGenLinLapackSolver::solve() -LAPACK routine returned 51
ArpackSolver::Error with _saupd info = -9999
Could not build an Arnoldi factorization.IPARAM(5) the size of the current Arnoldi factorization: is 3factorization. The user is advised to check thatenough workspace and array storage has been allocated.
WARNING DirectIntegrationAnalysis::eigen() - EigenSOE failed in solve()
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

I don't even know what the error means. Would you please help me with this? I do appreciate your help.I have also attached the code here:
Thanks very much.




#############################################################################################################################################
# Verification of the Propped Rocking Wall Test Specimen
# No Slack between Wall and Gravity Plates
# Afsoon Nicknam - University at Buffalo
# Units: kip/inch
#############################################################################################################################################
wipe;
model basic -ndm 2 -ndf 3;

# Wall Material & Section Definition #########################################################################################################
# Wall Material ...............................................................................................................................
# Unconfined Concrete parameters for Concrete07 Material
set Fy 60; # given by user
set fc -4.2; # given by user
set ecun -0.0021;
set Ec [expr (57000*[expr { sqrt([expr $fc*(-1)*1000]) }]/1000)];
set ft [expr (7.5*[expr { sqrt([expr $fc*(-1)*1000]) }]/1000)];
set et [expr 2*$ft/$Ec];
set xp 2;
set xnun 2
set run 3.7;

# Confined Concrete parameters for Concrete07 Material
set fcc -5.71; # given by user
set ecc [expr (-1*(0.002*(1+5*($fcc/$fc-1))))];
set Esec [expr $fcc/$ecc];
set rowx 0.00733; set rowy 0.008; # given by user
set rows [expr $rowx+$rowy];
set ecu [expr (0.004+1.4*$rows*$Fy*0.1/$fcc)];
set xnc [expr $ecu/$ecc];
set rc [expr $Ec/($Ec-$Esec)];

# Steel parameters for Steel02 Material (r=regular reinforcement as opposed to PT reinforcement)
set E0r 29000;
set br 0.02;
set R0r 20;
set CR1r 0.87;
set CR2r 0.15;

# Concrete (Unconfined and Confined)
uniaxialMaterial Concrete07 1 $fc $ecun $Ec $ft $et $xp $xnun $run;
uniaxialMaterial Concrete07 2 $fcc $ecc $Ec $ft $et $xp $xnc $rc;

# Steel (bound., web and horiz. reinforcement)
uniaxialMaterial Steel02 1001 $Fy $E0r $br $R0r $CR1r $CR2r;


# Define Wall Cross-Section ..................................................................................................................
set tw 8.0; set NStrip 5; # thickness
geomTransf LinearInt 1
set nintp 1; # int. points
set COR 0.4; # center of rotation

# Section definition
section FiberInt 1 -NStrip $NStrip $tw $NStrip $tw $NStrip $tw {
# Vertical fibers
fiber -14.25 0 9 1; # Cover concrete
fiber -12.75 0 2.81 2; fiber -12.75 0 0.88 1001;
fiber -10.75 0 17 2;
fiber -8.75 0 1.43 2; fiber -8.75 0 0.88 1001;
fiber -6.28 0 18.1 1;
fiber -4 0 0.22 1001;
fiber -2 0 16 1;
fiber 0 0 0.4 1001;
fiber 2 0 16 1;
fiber 4 0 0.22 1001;
fiber 6.28 0 18.1 1;
fiber 8.75 0 1.43 2; fiber 8.75 0 0.88 1001;
fiber 10.75 0 17 2;
fiber 12.75 0 2.81 2; fiber 12.75 0 0.88 1001;
fiber 14.25 0 9 1; # Cover concrete

# Horiz. reinf.
Hfiber 0 0 [expr 2*0.11/($tw*10)] 1001; # Vertical distance of the horizontal rebar is assumed to be 10"
}


# PT Material & Section Definition ##########################################################################################################
# PT Material (pt=PT) ..........................................................................................................................
set Fupt 150; # ksi
set Fypt [expr 0.8*$Fupt];
set Apt 1.25;
set Ept 29000;
set bpt 0.02;
set R0pt 20;
set CR1pt 0.87;
set CR2pt 0.15;

# West PT
set PTFptW [expr (61.28+57.36)/2];
set sigInitWPT [expr $PTFptW/$Apt];
uniaxialMaterial Steel02 101 $Fypt $Ept $bpt $R0pt $CR1pt $CR2pt 0 1 0 1 $sigInitWPT;
# Note: Initial strain could be used instead, using a parallel material: Steel02+InitialStrain (uniaxialMaterial InitStrainMaterial $matTag $otherTag $initStrain)

# East PT
set PTFptE [expr (47.36+54.86)/2];
set sigInitEPT [expr $PTFptE/$Apt];
uniaxialMaterial Steel02 102 $Fypt $Ept $bpt $R0pt $CR1pt $CR2pt 0 1 0 1 $sigInitEPT;
# Note: Initial strain could be used instead, using a parallel material: Steel02+InitialStrain (uniaxialMaterial InitStrainMaterial $matTag $otherTag $initStrain)



# BRB Material $ Section Definition #########################################################################################################
# Define BRB Geometry Paramters ...............................................................................................................
set LBar 49.5; # bar length
set LRigid [expr 0.5*(61.5-$LBar)]; # rigind end length


# Material Properties .......................................................................................................................
# Steel02 Material (1/3)
set Fybrb 36;
set Ebrb 29000;
set bbrb 0.01;
set R0 20;
set cR1 0.87;
set cR2 0.15;
set a1 0.09; # Compression
set a2 0.6; # Compression
set a3 0.09; # Tension
set a4 1; # Tension
set sigInit 0;
uniaxialMaterial Steel02 201 $Fybrb [expr 0.9*($Ebrb)] $bbrb $R0 $cR1 $cR2 $a1 $a2 $a3 $a4 $sigInit
uniaxialMaterial Elastic 202 $Ebrb


# Hardening Material (2/3)
set H_iso 0;
set H_kin 0;
set eta 0;
set sigmaY 0.01;
uniaxialMaterial Hardening 203 [expr 0.1*($Ebrb)] $sigmaY $H_iso $H_kin $eta


# Pinching Material (3/3)
source procUniaxialPinching.tcl
##### Positive/Negative envelope Stress/Load
### stress1 stress2 stress3 stress4
set pEnvelopeStress [list 0.001 0.001 0.001 0.001]
set nEnvelopeStress [list -8.0 -16.0 -25.0 -0.01]
### Positive/Negative envelope Strain/Deformation
## strain1 strain2 strain3 strain4
set pEnvelopeStrain [list 0.0012 [expr 1/($LBar)] [expr 1.5/($LBar)] [expr 1.5/($LBar)+0.001]]
set nEnvelopeStrain [list -0.0012 [expr (-1)/($LBar)] [expr (-1.2)/($LBar)] [expr (-1.2)/($LBar)-0.001]]
### Ratio of maximum deformation at which reloading begins
## Pos_env. Neg_env.
set rDisp [list 1 0.5]
### Ratio of envelope force (corresponding to maximum deformation) at which reloading begins
## Pos_env. Neg_env.
set rForce [list 0.001 0.25]
### Ratio of monotonic strength developed upon unloading
## Pos_env. Neg_env.
set uForce [list 0.001 0.001]
### Coefficients for Unloading Stiffness degradation
## gammaK1 gammaK2 gammaK3 gammaK4 gammaKLimit
#set gammaK [list 1.0 0.2 0.3 0.2 0.9]
set gammaK [list 0.0 0.0 0.0 0.0 0.0]
### Coefficients for Reloading Stiffness degradation
## gammaD1 gammaD2 gammaD3 gammaD4 gammaDLimit
#set gammaD [list 0.5 0.5 2.0 2.0 0.5]
set gammaD [list 0.0 0.0 0.0 0.0 0.0]
### Coefficients for Strength degradation
## gammaF1 gammaF2 gammaF3 gammaF4 gammaFLimit
#set gammaF [list 1.0 0.0 1.0 1.0 0.9]
set gammaF [list 0.0 0.0 0.0 0.0 0.0]
set gammaE 10
# material ID
set matID 204
# damage type (option: "energy", "cycle")
set dam "cycle"
# add the material to domain through the use of a procedure
procUniaxialPinching $matID $pEnvelopeStress $nEnvelopeStress $pEnvelopeStrain $nEnvelopeStrain $rDisp $rForce $uForce $gammaK $gammaD $gammaF $gammaE $dam


# Define Parallel Materials (1+2+3)
uniaxialMaterial Parallel 205 201 203 204


# Define BRB Sections .......................................................................................................................
set pi 3.141593;
set ABar [expr $pi*pow(0.25,2)];
set ARigid [expr $ABar*20];


# Nodes ######################################################################################################################################
# x-Coordinate Definition
set xcent 44.7;
set xpt 6;
set xbrb 29.7;
set xhwidth 15;
set xbrbt 20.7;

# y-Coordinate Definition
set a 6;
set h1 [expr 56+$a];
set h2 [expr 106.75+$a];
set h3 [expr 145+$a];
set hw [expr 156+$a];
set hbt [expr 69.2+$a];
set hbb [expr 12.5+$a];

# Nodes
node 1 0 $a; node 2 $xbrb $a ; node 3 $xcent $a; node 4 [expr $xcent+$xhwidth] $a; node 5 [expr $xcent+$xhwidth+$xbrb] $a; # node 6 0 $a;
node 7 $xbrb $a ; node 8 $xcent $a; node 9 [expr $xcent+$xhwidth] $a; # node 10 [expr $xcent+$xhwidth+$xbrb] $a;
node 11 $xcent $h1; # node 12 $xcent $h1;
node 13 $xcent $h2; # node 14 $xcent $h2;
node 15 $xcent $h3; # node 16 $xcent $h3;
node 17 [expr $xcent-$xpt] $hw; node 18 $xcent $hw; node 19 [expr $xcent+$xpt] $hw;
# Top of the BRBs
node 20 $xcent $hbt; node 21 [expr $xcent-$xbrbt] $hbt; node 22 [expr $xcent+$xbrbt] $hbt;
# Bottom of the BRBs
node 23 0 $hbb; node 24 [expr 2*$xbrb+2*$xhwidth] $hbb;
# Inside BRB West
set alpha [expr atan(($xcent-$xbrbt)/($hbt-$hbb))]; # in rad
node 25 [expr $xcent-$xbrbt-$LRigid*cos($alpha)] [expr $hbt-$LRigid*sin($alpha)];
node 27 [expr 0+$LRigid*cos($alpha)] [expr $hbb+$LRigid*sin($alpha)];
# Inside BRB East
node 26 [expr $xcent+$xbrbt+$LRigid*cos($alpha)] [expr $hbt-$LRigid*sin($alpha)];
node 28 [expr 2*$xbrb+2*$xhwidth-$LRigid*cos($alpha)] [expr $hbb+$LRigid*sin($alpha)];
# First floor wall nodes
set dh 6;
node 101 $xcent [expr 1*$dh+$a];
node 102 $xcent [expr 2*$dh+$a];
node 103 $xcent [expr 3*$dh+$a];
node 104 $xcent [expr 4*$dh+$a];
node 105 $xcent [expr 5*$dh+$a];
node 106 $xcent [expr 6*$dh+$a];
node 107 $xcent [expr 7*$dh+$a];
node 108 $xcent [expr 8*$dh+$a];
# Second floor BELOW BRB wall nodes
node 201 $xcent [expr $h1+1*$dh];
# Second floor ABOVE BRB wall nodes
node 202 $xcent [expr $hbt+1*$dh];
node 203 $xcent [expr $hbt+2*$dh];
node 204 $xcent [expr $hbt+3*$dh];
node 205 $xcent [expr $hbt+4*$dh];
node 206 $xcent [expr $hbt+5*$dh];
# Third floor wall nodes
node 301 $xcent [expr $h2+1*$dh];
node 302 $xcent [expr $h2+2*$dh];
node 303 $xcent [expr $h2+3*$dh];
node 304 $xcent [expr $h2+4*$dh];
node 305 $xcent [expr $h2+5*$dh];
# Nodes at the lower end of the PT bars + Foundation Complience
node 1001 [expr $xcent-$xpt] 0; node 1002 $xcent 0; node 1003 [expr $xcent+$xpt] 0; node 1004 $xcent 0;


# Mass Definition ###########################################################################################################################
mass 11 0.0443 0. 0.;
mass 13 0.0442 0. 0.;
mass 15 0.0443 0. 0.;


# Element Definition #########################################################################################################################
# Wall Elements ...............................................................................................................................
# First Floor
element dispBeamColumnInt 11 3 101 $nintp 1 1 $COR;
element dispBeamColumnInt 12 101 102 $nintp 1 1 $COR;
element dispBeamColumnInt 13 102 103 $nintp 1 1 $COR;
element dispBeamColumnInt 14 103 104 $nintp 1 1 $COR;
element dispBeamColumnInt 15 104 105 $nintp 1 1 $COR;
element dispBeamColumnInt 16 105 106 $nintp 1 1 $COR;
element dispBeamColumnInt 17 106 107 $nintp 1 1 $COR;
element dispBeamColumnInt 18 107 108 $nintp 1 1 $COR;
element dispBeamColumnInt 19 108 11 $nintp 1 1 $COR;
# Second Floor BELOW BRB
element dispBeamColumnInt 20 11 201 $nintp 1 1 $COR;
element dispBeamColumnInt 21 201 20 $nintp 1 1 $COR;
# Second Floor ABOVE BRB
element dispBeamColumnInt 22 20 202 $nintp 1 1 $COR;
element dispBeamColumnInt 23 202 203 $nintp 1 1 $COR;
element dispBeamColumnInt 24 203 204 $nintp 1 1 $COR;
element dispBeamColumnInt 25 204 205 $nintp 1 1 $COR;
element dispBeamColumnInt 26 205 206 $nintp 1 1 $COR;
element dispBeamColumnInt 27 206 13 $nintp 1 1 $COR;
# Third Floor
element dispBeamColumnInt 31 13 301 $nintp 1 1 $COR;
element dispBeamColumnInt 32 301 302 $nintp 1 1 $COR;
element dispBeamColumnInt 33 302 303 $nintp 1 1 $COR;
element dispBeamColumnInt 34 303 304 $nintp 1 1 $COR;
element dispBeamColumnInt 35 304 305 $nintp 1 1 $COR;
element dispBeamColumnInt 36 305 15 $nintp 1 1 $COR;
element dispBeamColumnInt 37 15 18 $nintp 1 1 $COR;


# PT Elements ...............................................................................................................................
# West PT
element corotTruss 101 1001 17 $Apt 101;
# East PT
element corotTruss 102 1003 19 $Apt 102;


# BRB Elements .............................................................................................................................
# West BRB
element corotTruss 205 27 25 $ABar 205;
element corotTruss 201 25 21 $ARigid 202;
element corotTruss 203 23 27 $ARigid 202;

# East BRB
element corotTruss 206 28 26 $ABar 205;
element corotTruss 202 26 22 $ARigid 202;
element corotTruss 204 24 28 $ARigid 202;


# GAP Elements ............................................................................................................................
set Egap 2E10; # <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< NEEDS TO BE ADJUSTED
set Fygap 4E10; # <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< NEEDS TO BE ADJUSTED
set gap 0;
set MatGap 301;
uniaxialMaterial ElasticPPGap $MatGap $Egap $Fygap $gap
proc gapelement {eleIDgap nodeRgap nodeCgap matID1gap} {
element zeroLength $eleIDgap $nodeRgap $nodeCgap -mat $matID1gap -dir 2
equalDOF $nodeRgap $nodeCgap 1
}
gapelement 301 7 2 $MatGap;
gapelement 302 8 3 $MatGap;
gapelement 303 9 4 $MatGap;
# Note that the number of the gap elements used is 3 (as the first trial), but a larger number can be used.

# Rigid Elements (RE) ............................................................................................................................
set ERE 29000;
set ARE 20;
uniaxialMaterial Elastic 4000 $ERE
# Wall Top
element corotTruss 401 17 18 $ARE 4000;
element corotTruss 402 18 19 $ARE 4000;
# Wall/BRB Connection
element corotTruss 403 21 20 $ARE 4000;
element corotTruss 404 20 22 $ARE 4000;
# BRB/Base Plate Connection
element corotTruss 405 1 23 $ARE 4000;
element corotTruss 406 5 24 $ARE 4000;
# Wall Base
element corotTruss 407 2 3 $ARE 4000;
element corotTruss 408 3 4 $ARE 4000;
# Base Plate
element corotTruss 409 1 7 $ARE 4000;
element corotTruss 410 7 8 $ARE 4000;
element corotTruss 411 8 9 $ARE 4000;
element corotTruss 412 9 5 $ARE 4000;
# Base Plate/PT Anchorage Connection
element corotTruss 413 1002 8 [expr 10*$ARE] 4000;
# PT Anchorage Level
element corotTruss 414 1001 1002 [expr 10*$ARE] 4000;
element corotTruss 415 1002 1003 [expr 10*$ARE] 4000;


# Define the Base Rotational Spring (To account for the foundation complience) .............................................................
set Espr 20000; # <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< NEEDS TO BE ADJUSTED
set MatRotSpr 1002;
uniaxialMaterial Elastic $MatRotSpr $Espr;
proc rotSpring2D {eleID nodeR nodeC matID1} {
element zeroLength $eleID $nodeR $nodeC -mat $matID1 -dir 6
equalDOF $nodeR $nodeC 1 2
}
rotSpring2D 1002 1004 1002 $MatRotSpr;


# EDOF Definitions (Constraints) #############################################################################################################
# There is no extra rigid constraints defined in the model as Rigid Truss Elements have been used instead.

# Boundary Conditions ########################################################################################################################
fix 1 1 1 1; # No Rocking & No Foundation Complience
fix 2 1 1 1;
fix 3 1 1 1;
fix 4 1 1 1;
fix 5 1 1 1;
fix 7 1 1 1;
fix 8 1 1 1;
fix 9 1 1 1;
fix 1001 1 1 1;
fix 1002 1 1 1;
fix 1003 1 1 1;

# Modal Analysis ############################################################################################################################
set numModes 3;
set lambda [eigen $numModes];

[vesna]

You have defined only three inertial degrees of freedom and you are requesting 3 eigenvalues which the default solver can not provide. The default solver can return n-1 eigenvalues, n being # of inertial DOFs.

[anicknam]

Thanks a lot for your response Vesna. I just tried 2 as the requested number of eigenvalues but I still get the same error message. Do I need to change the default solver? If yes, how would I do that?

[vesna]

In that case you may have a problem within your model.

Another solver you can try is -fullGenLapack

You may also try doing eigen analysis after gravity.

[anicknam]

Thanks Vesna. I tried to break my model into simpler elements and so I started off with my wall only (fixed at the base) and then I applied "-fullGenLapack" as the eigen solver which gave me reasonable Periods and Mode shapes. Then I added a rotational spring at the base and it still gave me reasonable eigenvalues(and vectors). However, now that I want to attach two rigid elements at the top of my wall on each side, again it is showing me irrelevant periods. Here is the error message:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
FullGenEigenSolver::solve() - the eigenvalue 1 is numerically undetermined or infinite
FullGenEigenSolver::solve() - the eigenvalue 2 is numerically undetermined or infinite
FullGenEigenSolver::solve() - the eigenvalue 3 is numerically undetermined or infinite
Periods are 4.6862143823297825e-154 4.6862143823297825e-154 4.6862143823297825e-154
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Is it not possible to directly attach a rigid element to an element with fiber section or the error lies in a different place. Would you please help me with this?

I have attached the simplified code here. Thanks very much.

##############################################################################################################################################
# Verification of the Propped Rocking Wall Test Specimen
# No Slack between Wall and Gravity Plates
# Afsoon Nicknam - University at Buffalo
# Units: kip/inch
##############################################################################################################################################
wipe;
model basic -ndm 2 -ndf 3;

# Wall Material & Section Definition #########################################################################################################
# Wall Material ...............................................................................................................................
# Unconfined Concrete parameters for Concrete07 Material
set Fy 60; # given by user
set fc -4.2; # given by user
set ecun -0.0021;
set Ec [expr (57000*[expr { sqrt([expr $fc*(-1)*1000]) }]/1000)];
set ft [expr (7.5*[expr { sqrt([expr $fc*(-1)*1000]) }]/1000)];
set et [expr 2*$ft/$Ec];
set xp 2;
set xnun 2
set run 3.7;

# Confined Concrete parameters for Concrete07 Material
set fcc -5.71; # given by user
set ecc [expr (-1*(0.002*(1+5*($fcc/$fc-1))))];
set Esec [expr $fcc/$ecc];
set rowx 0.00733; set rowy 0.008; # given by user
set rows [expr $rowx+$rowy];
set ecu [expr (0.004+1.4*$rows*$Fy*0.1/$fcc)];
set xnc [expr $ecu/$ecc];
set rc [expr $Ec/($Ec-$Esec)];

# Steel parameters for Steel02 Material (r=regular reinforcement as opposed to PT reinforcement)
set E0r 29000;
set br 0.02;
set R0r 20;
set CR1r 0.87;
set CR2r 0.15;

# Concrete (Unconfined and Confined)
uniaxialMaterial Concrete07 1 $fc $ecun $Ec $ft $et $xp $xnun $run;
uniaxialMaterial Concrete07 2 $fcc $ecc $Ec $ft $et $xp $xnc $rc;

# Steel (bound., web and horiz. reinforcement)
uniaxialMaterial Steel02 1001 $Fy $E0r $br $R0r $CR1r $CR2r;


# Define Wall Cross-Section ..................................................................................................................
set tw 8.0; set NStrip 5; # thickness
geomTransf LinearInt 1
set nintp 1; # int. points
set COR 0.4; # center of rotation

# Section definition
section FiberInt 1 -NStrip $NStrip $tw $NStrip $tw $NStrip $tw {
# Vertical fibers
fiber -14.25 0 9 1; # Cover concrete
fiber -12.75 0 2.81 2; fiber -12.75 0 0.88 1001;
fiber -10.75 0 17 2;
fiber -8.75 0 1.43 2; fiber -8.75 0 0.88 1001;
fiber -6.28 0 18.1 1;
fiber -4 0 0.22 1001;
fiber -2 0 16 1;
fiber 0 0 0.4 1001;
fiber 2 0 16 1;
fiber 4 0 0.22 1001;
fiber 6.28 0 18.1 1;
fiber 8.75 0 1.43 2; fiber 8.75 0 0.88 1001;
fiber 10.75 0 17 2;
fiber 12.75 0 2.81 2; fiber 12.75 0 0.88 1001;
fiber 14.25 0 9 1; # Cover concrete

# Horiz. reinf.
Hfiber 0 0 [expr 2*0.11/($tw*10)] 1001; # Vertical distance of the horizontal rebar is assumed to be 10"
}


# Nodes ######################################################################################################################################
# x-Coordinate Definition
set xcent 44.7;
set xpt 6;
set xbrb 29.7;
set xhwidth 15;
set xbrbt 20.7;

# y-Coordinate Definition
set a 6;
set h1 [expr 56+$a];
set h2 [expr 106.75+$a];
set h3 [expr 145+$a];
set hw [expr 156+$a];
set hbt [expr 69.2+$a];
set hbb [expr 12.5+$a];

# Nodes
node 3 $xcent $a;
node 8 $xcent $a;
node 11 $xcent $h1;
node 13 $xcent $h2;
node 15 $xcent $h3;
node 17 [expr $xcent-$xpt] $hw;
node 18 $xcent $hw;
node 19 [expr $xcent+$xpt] $hw;
node 20 $xcent $hbt;
## First floor wall nodes
set dh 6;
node 101 $xcent [expr 1*$dh+$a];
node 102 $xcent [expr 2*$dh+$a];
node 103 $xcent [expr 3*$dh+$a];
node 104 $xcent [expr 4*$dh+$a];
node 105 $xcent [expr 5*$dh+$a];
node 106 $xcent [expr 6*$dh+$a];
node 107 $xcent [expr 7*$dh+$a];
node 108 $xcent [expr 8*$dh+$a];
# Second floor BELOW BRB wall nodes
node 201 $xcent [expr $h1+1*$dh];
# Second floor ABOVE BRB wall nodes
node 202 $xcent [expr $hbt+1*$dh];
node 203 $xcent [expr $hbt+2*$dh];
node 204 $xcent [expr $hbt+3*$dh];
node 205 $xcent [expr $hbt+4*$dh];
node 206 $xcent [expr $hbt+5*$dh];
# Third floor wall nodes
node 301 $xcent [expr $h2+1*$dh];
node 302 $xcent [expr $h2+2*$dh];
node 303 $xcent [expr $h2+3*$dh];
node 304 $xcent [expr $h2+4*$dh];
node 305 $xcent [expr $h2+5*$dh];



# Mass Definition ###########################################################################################################################
mass 11 0.0443 0. 0.;
mass 13 0.0442 0. 0.;
mass 15 0.0443 0. 0.;


# Element Definition #########################################################################################################################
# Wall Elements ...............................................................................................................................
# First Floor
element dispBeamColumnInt 11 3 101 $nintp 1 1 $COR;
element dispBeamColumnInt 12 101 102 $nintp 1 1 $COR;
element dispBeamColumnInt 13 102 103 $nintp 1 1 $COR;
element dispBeamColumnInt 14 103 104 $nintp 1 1 $COR;
element dispBeamColumnInt 15 104 105 $nintp 1 1 $COR;
element dispBeamColumnInt 16 105 106 $nintp 1 1 $COR;
element dispBeamColumnInt 17 106 107 $nintp 1 1 $COR;
element dispBeamColumnInt 18 107 108 $nintp 1 1 $COR;
element dispBeamColumnInt 19 108 11 $nintp 1 1 $COR;
# Second Floor BELOW BRB
element dispBeamColumnInt 20 11 201 $nintp 1 1 $COR;
element dispBeamColumnInt 21 201 20 $nintp 1 1 $COR;
# Second Floor ABOVE BRB
element dispBeamColumnInt 22 20 202 $nintp 1 1 $COR;
element dispBeamColumnInt 23 202 203 $nintp 1 1 $COR;
element dispBeamColumnInt 24 203 204 $nintp 1 1 $COR;
element dispBeamColumnInt 25 204 205 $nintp 1 1 $COR;
element dispBeamColumnInt 26 205 206 $nintp 1 1 $COR;
element dispBeamColumnInt 27 206 13 $nintp 1 1 $COR;
# Third Floor
element dispBeamColumnInt 31 13 301 $nintp 1 1 $COR;
element dispBeamColumnInt 32 301 302 $nintp 1 1 $COR;
element dispBeamColumnInt 33 302 303 $nintp 1 1 $COR;
element dispBeamColumnInt 34 303 304 $nintp 1 1 $COR;
element dispBeamColumnInt 35 304 305 $nintp 1 1 $COR;
element dispBeamColumnInt 36 305 15 $nintp 1 1 $COR;
element dispBeamColumnInt 37 15 18 $nintp 1 1 $COR;


# Rigid Elements (RE) ............................................................................................................................
set ERE 29000;
set ARE 20;
uniaxialMaterial Elastic 4000 $ERE
# Wall Top
element truss 401 17 18 $ARE 4000;
element truss 402 18 19 $ARE 4000;



## Define the Base Rotational Spring (To account for the foundation complience) .............................................................
set Espr 200000; # <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< NEEDS TO BE ADJUSTED
set MatRotSpr 1002;
uniaxialMaterial Elastic $MatRotSpr $Espr;
proc rotSpring2D {eleID nodeR nodeC matID1} {
element zeroLength $eleID $nodeR $nodeC -mat $matID1 -dir 6
equalDOF $nodeR $nodeC 1 2
}
rotSpring2D 83 8 3 $MatRotSpr;


# EDOF Definitions (Constraints) #############################################################################################################
# There is no extra rigid constraints defined in the model as Rigid Truss Elements have been used instead.
equalDOF 18 17 1;
equalDOF 18 19 1;

# Boundary Conditions ########################################################################################################################
fix 8 1 1 1; # No Rocking


# Eigen-Value Analysis ######################################################################################################################
# Create Data Directory
file mkdir Modes;

# record eigenvectors
set numModes 3;
for { set k 1 } { $k <= $numModes } { incr k } {
recorder Node -file [format "Modes/Mode%i.out" $k] -node 3 11 13 15 -dof 1 2 3 "eigen $k"
}

# perform eigen analysis
set lambda [eigen -fullGenLapack $numModes];

# calculate frequencies and periods of the structure
set omega {}
set f {}
set T {}
set pi 3.141593

foreach lam $lambda {
lappend omega [expr sqrt($lam)]
lappend f [expr sqrt($lam)/(2*$pi)]
lappend T [expr (2*$pi)/sqrt($lam)]
}

puts "Periods are $T"

# write the output file cosisting of periods
set period "Modes/Periods.txt"
set Periods [open $period "w"]
foreach t $T {
puts $Periods " $t"
}
close $Periods

# record the eigenvectors
record

[anicknam]

I have come up with the following questions, I would appreciate if anyone could help me them:

1) Is it not possible to directly attach a truss element (with high stiffness to work as a rigid element) to an element with fiber section (e.g. dispBeamColumnInt or dispBeamColumn, etc). Do we have to use an elastic beam element instead?

2) Does a truss element introduce hinge (no moment) connections at its two ends by default?

3) I have been looking through the message board for a while and reading different comments about how to model a shear wall. In my case, I am trying to verify a numerical model of my shear wall (which is allowed to rock at the base) with my test data. The wall remained essentially elastic over the entire range of tests we performed and therefore, I am not looking for any nonlinearity in my wall. The test were all shake table tests. So, I started off with dispBeamColumnInt (with large number of element along the height of the wall) , but now I would like to run a cyclic pushover analysis on my model to check its hysteretic performance. But, apparently that's not an option for this type of element. Then I decided to use dispBeamColumn, but then I read a post from Vesna saying that dispBeamColumn is not the best element to model shear wall. I am not sure which type of element I should use for my wall, so that I could conduct both cyclic Pushover and time-history analysis, given I don't expect my wall to go nonlinear. Could forceBeamColumn with large number of integration points be an option?

Again, I would appreciate if I could get your thoughts on the above.

[vesna]

1) in the case that the truss element with high stiffness works for you, go for it

2) yes, truss elements are pinned at their ends

3) if your wall is going to stay completely elastic you can use any of the mentioned elements or just simple elasticBeamColumn

[anicknam]

Thanks for your response Vesna. Regarding the 2nd and 3rd questions:

2) So, if I need to use a number of truss elements in series, do I have to connect them with elastic rotational springs to avoid buckling, or there's a better way to do that? I am asking this because I use three truss elements in series to model my Buckling-Restrained Braces (BRB), one in the middle for the steel core and two on sides that act like rigid elements. I am using parallel uni-axial material for the one in the middle. Can I do the configuration using beam elements?


3) Given the fact that dispBeamColumnInt cannot be used for cyclic pushover analysis and given that I need to check the hysteretic performance of my wall under cyclic loading, if I want to use distributed plasticity model, I think I am left with two options: forceBeamColumn and dispBeamColumn. I read a post earlier from you in which you pointed out that the disBeamColumn element is not the best choice for to model shear walls. Is such element not the best choice even if the wall remains elastic?

Thanks very much.

[vesna]

1) three truss elements in series (in the same line) are typical example of unstable system.

2) although dispBeamColumn is not the best choice for modeling a shear wall, it can be used for modeling your rocking wall if (as you say) your wall stays elastic.

[nhytb]

Hi, could you please explain for me how to model a BRB, I mean what element and what kind of material should I use?
I red that somebody used SteelBRB, but what is the parameters of this material?
thank you alot.

[baikunthasilwal]

Hi everyone,

I have also same modeling issue for BRB. Please provide some important modeling concern to improve the BRB model and selecting appropriate material model.

[ahmadbsr]

Hi i am facing with this problem how can i fix it?
# In The Name Of God
# AHMAD BSR
# George D.Hatzigeorgiou a, AsteriosA.Liolios Model
# 2D Concrete Frame Model
# Irregular ,Model/ 3 Story
# Units KN,M
wipe ;
wipeAnalysis ;
model BasicBuilder -ndm 2 -ndf 3 ;
# define Parameters
set displayMode "displayON"
set L1 5.00 ;
set H1 3.00 ;
set DL 2000.0 ;
set LL 0 ;
set mConc 2000.0 ;
set FileName "3Story.irregular Model"
file mkdir $FileName ;
set fc 25e6 ;
set Ec 23153.2e6 ;
set Cover 0.04 ;
set pi 3.141592654 ;
# Define nodes
# Define nodes
# Base nodes
# X Y
node 1 0.0 0.0 ;
node 2 $L1 0.0 ;
node 3 [expr 2*$L1] 0.0 ;
node 4 [expr 3*$L1] 0.0 ;
node 5 [expr 3*$L1] 0.0 ;
node 6 [expr 2*$L1] 0.0 ;
node 7 $L1 0.0 ;
node 8 0.0 0.0 ;

# First Floor
node 11 0.0 $H1 ;
node 12 $L1 $H1 ;
node 13 [expr 2*$L1] $H1 ;
node 14 [expr 3*$L1] $H1 ;
node 115 2.5 $H1 ;
node 15 [expr 3*$L1] $H1 ;
node 155 [expr 3*$L1] $H1 ;
node 16 [expr 2*$L1] $H1 ;
node 166 [expr 2*$L1] $H1 ;
node 17 $L1 $H1 ;
node 177 $L1 $H1 ;
node 18 0.0 $H1 ;
node 188 0.0 $H1 ;;
node 135 12.5 [expr 1*$H1]
#Second Floor
node 21 0.0 [expr 2*$H1] ;
node 22 $L1 [expr 2*$H1] ;
node 23 [expr 2*$L1] [expr 2*$H1] ;
node 266 [expr 2*$L1] [expr 2*$H1] ;
node 27 $L1 [expr 2*$H1] ;
node 277 $L1 [expr 2*$H1] ;
node 28 0.0 [expr 2*$H1] ;
node 288 0.0 [expr 2*$H1] ;

node 215 2.5 [expr 2*$H1]
node 225 7.5 [expr 2*$H1]
# Third Floor
node 31 0.0 [expr 3*$H1] ;
node 32 $L1 [expr 3*$H1] ;
node 377 $L1 [expr 3*$H1] ;
node 388 0.0 [expr 3*$H1] ;



# First Floor
equalDOF 188 115 1
equalDOF 188 177 1
equalDOF 188 166 1
equalDOF 188 135 1

equalDOF 188 155 1
# Second Floor
equalDOF 288 215 1
equalDOF 288 277 1
equalDOF 288 225 1
equalDOF 288 266 1

# Third Floor
equalDOF 388 377 1
## Define Constraints
fix 1 1 1 1 ;
fix 2 1 1 1 ;
fix 3 1 1 1 ;
fix 4 1 1 1 ;
#
#fix 188 0 0 1
#fix 177 0 0 1
#fix 166 0 0 1
#fix 155 0 0 1
#fix 288 0 0 1
#fix 277 0 0 1
#fix 266 0 0 1
#fix 388 0 0 1
#fix 377 0 0 1

set g 9.86 ;
#set WeightFloor3 13289.6 ;
#set WeightFloor2 26579.2 ;
#set WeightFloor1 39868.8 ;
#set Weightfloor1Bay [expr ($WeightFloor1/3.0)] ;
#set Weightfloor2Bay [expr ($WeightFloor2/2.0)] ;
#set Weightfloor3Bay $WeightFloor3 ;
#
#


set WeightFloor3 [expr (39868.] ;
set WeightFloor2 [expr (53865.6)] ;
set WeightFloor1 [expr (29579.2)] ;
set Weightfloor1Bay [expr ($WeightFloor1/3.0)] ;
set Weightfloor2Bay [expr ($WeightFloor2/3.0)] ;
set Weightfloor3Bay [expr ($WeightFloor3/3.0)] ;



mass 188 [expr ((($Weightfloor1Bay/$g)/2)+(3181.0+3181.0+50000)/$g)] 1.e-9 0. ;
mass 177 [expr (($Weightfloor1Bay/$g)+(3181.0+3181.0+100000/$g))] 1.e-9 0. ;
mass 166 [expr (($Weightfloor1Bay/$g)+(3181.0+3181.0+100000/$g))] 1.e-9 0. ;
mass 155 [expr ((($Weightfloor1Bay/$g)/2)+(3181.0+50000)/$g)] 1.e-9 0. ;


mass 288 [expr ((($Weightfloor2Bay/$g)/2)+(3181.0+3181.0+50000)/$g)] 1.e-9 0. ;
mass 277 [expr (($Weightfloor2Bay/$g)+(3181.0+3181.0+100000)/$g)] 1.e-9 0. ;
mass 266 [expr ((($Weightfloor2Bay/$g)/2)+(3181.0+3181.0+50000)/$g)] 1.e-9 0. ;



mass 388 [expr ((($Weightfloor3Bay/$g)/2)+(3181.0+50000)/$g)] 1.e-9 0. ;
mass 377 [expr ((($Weightfloor3Bay/$g)/2)+(3181.0+50000)/$g)] 1.e-9 0. ;

# Define Constraints
#fix 8 1 1 1 ;
#fix 7 1 1 1 ;
#fix 6 1 1 1 ;
#fix 5 1 1 1 ;
#

#rigidLink beam 11 14
# Define Material
set fc1C 266 ; # CONFINED concrete (mander model), maximum stress
set eps1C [expr 2.*$fc1C/$Ec]; # strain at maximum stress
set fc2C [expr 0.2*$fc1C]; # ultimate stress
set eps2C [expr 5*$eps1C]; # strain at ultimate stress
# unconfined concrete
set fc1U 20e6; # UNCONFINED concrete (todeschini parabolic model), maximum stress
set eps1U -0.003; # strain at maximum strength of unconfined concrete
set fc2U [expr 0.2*$fc1U]; # ultimate stress
set eps2U -0.01; # strain at ultimate stress
set lambda 0.1; # ratio between unloading slope at $eps2 and initial slope $Ec
# tensile-strength properties
set ftC [expr -0.14*$fc1C]; # tensile strength +tension
set ftU [expr -0.14*$fc1U]; # tensile strength +tension
set Ets [expr $ftU/0.002]; # tension softening stiffness

# Define Material
# n,mm
# Define Steel matTag fy fu Es Esh esh eult
uniaxialMaterial Steel02 1 500e6 2e11 0.01 15 .925 0.15
uniaxialMaterial Steel02 41 500e6 2e11 0.01 15 .925 0.15

# (Confined) matTag
uniaxialMaterial Concrete06 2 -28e6 -0.003 2.91 1 0.32 1.38e6 0.00008 0.4 0.08; # build cover concrete (confined)

uniaxialMaterial Concrete06 3 -24e6 -0.003 1.88 1 0.32 1.38e6 0.00008 0.4 0.08; # build cover concrete (unconfined)



#uniaxialMaterial Concrete02 2 $fc1C $eps1C $fc2C $eps2C $lambda $ftC $Ets;
#
#uniaxialMaterial Concrete03 3 $fc1U $eps1U $fc2U # build core concrete (confined)# build core concrete (confined)

## (Unconfined)
#uniaxialMaterial Concrete02 3 $fc1U $eps1U $fc2U $eps2U $lambda $ftU $Ets; # build cover concrete (unconfined)
## Define Sections
#uniaxialMaterial Concrete01 2 -24.e3 -0.002 -4.8e3 -0.005
##uniaxialMaterial Concrete01 3 -28.e3 -0.0024 -5.6e3 -0.015
## Define Sections
# Columns C 30*30 18

set CoreMat 2 ;
set CoverMat 3 ;
set BarMatC 1 ;
set UpNum 3 ;
set MidNum 2 ;
set DownNum 3 ;
set space [expr (0.3-(2.0*$Cover))/2] ;

set UpA18 [expr pow(9.e-3,2)*2*asin(1)];
set UpA22 [expr pow(11.e-3,2)*2*asin(1)] ;
set DownA18 [expr pow(9.e-3,2)*2*asin(1)] ;
set DownA22 [expr pow(11.e-3,2)*2*asin(1)] ;
set MidA18 [expr pow(9.e-3,2)*2*asin(1)] ;
set MidA22 [expr pow(11.e-3,2)*2*asin(1)] ;
###### sotun
set c 0.3
set c2 [expr $c-(2*$Cover)]
set space [expr ($c-(2.0*$Cover))/2] ;

#########tip 2 tir dar tabaghe 2
set h 0.4
set h2 [expr $h-(2*$Cover)]

set b 0.3
set b2 [expr $b-(2*$Cover)]



section Fiber 303018 { ;
patch quad $CoreMat 20 20 [expr -$c2/2] [expr $c2/2] [expr -$c2/2] [expr -$c2/2] [expr $c2/2] [expr -$c2/2] [expr $c2/2] [expr $c2/2]
patch quad $CoverMat 20 6 [expr -$c/2] [expr $c2/2] [expr -$c/2] [expr -$c2/2] [expr -$c2/2] [expr -$c2/2] [expr -$c2/2] [expr $c2/2]
patch quad $CoverMat 20 6 [expr $c2/2] [expr $c2/2] [expr $c2/2] [expr -$c2/2] [expr $c/2] [expr -$c2/2] [expr $c/2] [expr $c2/2]
patch quad $CoverMat 6 20 [expr -$c/2] [expr -$c2/2] [expr -$c/2] [expr -$c/2] [expr $c/2] [expr -$c/2] [expr $c/2] [expr -$c2/2]
patch quad $CoverMat 6 20 [expr -$c/2] [expr $c/2] [expr -$c/2] [expr $c2/2] [expr $c/2] [expr $c2/2] [expr $c/2] [expr $c/2]


# MatTag BarNum BarA YStart ZStart YEnd ZEnd

layer straight $BarMatC 3 [expr pow(9e-3,2)*2*asin(1)] [expr $h2/2] [expr $b2/2] [expr $h2/2] [expr -$b2/2]
layer straight $BarMatC 3 [expr pow(9e-3,2)*2*asin(1)] [expr -$h2/2] [expr $b2/2] [expr -$h2/2] [expr -$b2/2]
layer straight $BarMatC 2 [expr pow(9e-3,2)*2*asin(1)] 0.0 [expr $b2/2] 0.0 [expr -$b2/2]
} ;

# Column C 30*30 22
section Fiber 303022 { ;
# MatTag Nij Njk yi zi yj zj yk zk yl zl
patch quad $CoreMat 20 20 [expr -$c2/2] [expr $c2/2] [expr -$c2/2] [expr -$c2/2] [expr $c2/2] [expr -$c2/2] [expr $c2/2] [expr $c2/2]
patch quad $CoverMat 20 6 [expr -$c/2] [expr $c2/2] [expr -$c/2] [expr -$c2/2] [expr -$c2/2] [expr -$c2/2] [expr -$c2/2] [expr $c2/2]
patch quad $CoverMat 20 6 [expr $c2/2] [expr $c2/2] [expr $c2/2] [expr -$c2/2] [expr $c/2] [expr -$c2/2] [expr $c/2] [expr $c2/2]
patch quad $CoverMat 6 20 [expr -$c/2] [expr -$c2/2] [expr -$c/2] [expr -$c/2] [expr $c/2] [expr -$c/2] [expr $c/2] [expr -$c2/2]
patch quad $CoverMat 6 20 [expr -$c/2] [expr $c/2] [expr -$c/2] [expr $c2/2] [expr $c/2] [expr $c2/2] [expr $c/2] [expr $c/2]




# MatTag BarNum BarA YStart ZStart YEnd ZEnd

layer straight $BarMatC 3 [expr pow(11e-3,2)*2*asin(1)] [expr $h2/2] [expr $b2/2] [expr $h2/2] [expr -$b2/2]
layer straight $BarMatC 3 [expr pow(11e-3,2)*2*asin(1)] [expr -$h2/2] [expr $b2/2] [expr -$h2/2] [expr -$b2/2]
layer straight $BarMatC 2 [expr pow(11e-3,2)*2*asin(1)] 0.0 [expr $b2/2] 0.0 [expr -$b2/2]
} ;
puts "ahmad"
#Beam B30/40
set CoreBMat 12 ;
set BarMatB 41 ;
set BB1 0.3 ;
set D1 0.40 ;
set BB2 [expr $BB1/2] ;
set D2 [expr $D1/2] ;
set D3 [expr ($D1/2)-$Cover] ;
set BB3 [expr ($BB1/2)-$Cover] ;
set fcb [expr 1.3*$fc] ;
set eps1b [expr 2.*$fcb/$Ec];
set fc2b [expr 0.2*$fcb] ;
set eps2b [expr 5*$eps1b] ;
set BarAB [expr pow(8.e-3,2)*2*asin(1)] ;
uniaxialMaterial Concrete06 12 28e6 -0.0038 1.88 1 0.32 1.38e6 0.00008 0.4 0.08 ; # build core concrete (confined)

section Fiber 30405 { ;
# MatTag Nij Njk yi zi yj zj yk zk yl zl
patch quad $CoreBMat 20 20 [expr -$h2/2] [expr $b2/2] [expr -$h2/2] [expr -$b2/2] [expr $h2/2] [expr -$b2/2] [expr $h2/2] [expr $b2/2]
patch quad $CoverMat 20 6 [expr -$h/2] [expr $b2/2] [expr -$h/2] [expr -$b2/2] [expr -$h2/2] [expr -$b2/2] [expr -$h2/2] [expr $b2/2]
patch quad $CoverMat 20 6 [expr $h2/2] [expr $b2/2] [expr $h2/2] [expr -$b2/2] [expr $h/2] [expr -$b2/2] [expr $h/2] [expr $b2/2]
patch quad $CoverMat 6 20 [expr -$h/2] [expr -$b2/2] [expr -$h/2] [expr -$b/2] [expr $h/2] [expr -$b/2] [expr $h/2] [expr -$b2/2]
patch quad $CoverMat 6 20 [expr -$h/2] [expr $b/2] [expr -$h/2] [expr $b2/2] [expr $h/2] [expr $b2/2] [expr $h/2] [expr $b/2]

layer straight $BarMatC 5 [expr pow(8e-3,2)*2*asin(1)] [expr $b2/2] [expr $h2/2] [expr $h2/2] [expr -$b2/2]
layer straight $BarMatC 3 [expr pow(8e-3,2)*2*asin(1)] [expr $b2/2] [expr -$h2/2] [expr -$h2/2] [expr -$b2/2]
};
section Fiber 30406 { ;
# MatTag Nij Njk yi zi yj zj yk zk yl zl
patch quad $CoreBMat 20 20 [expr -$h2/2] [expr $b2/2] [expr -$h2/2] [expr -$b2/2] [expr $h2/2] [expr -$b2/2] [expr $h2/2] [expr $b2/2]
patch quad $CoverMat 20 6 [expr -$h/2] [expr $b2/2] [expr -$h/2] [expr -$b2/2] [expr -$h2/2] [expr -$b2/2] [expr -$h2/2] [expr $b2/2]
patch quad $CoverMat 20 6 [expr $h2/2] [expr $b2/2] [expr $h2/2] [expr -$b2/2] [expr $h/2] [expr -$b2/2] [expr $h/2] [expr $b2/2]
patch quad $CoverMat 6 20 [expr -$h/2] [expr -$b2/2] [expr -$h/2] [expr -$b/2] [expr $h/2] [expr -$b/2] [expr $h/2] [expr -$b2/2]
patch quad $CoverMat 6 20 [expr -$h/2] [expr $b/2] [expr -$h/2] [expr $b2/2] [expr $h/2] [expr $b2/2] [expr $h/2] [expr $b/2]

layer straight $BarMatC 6 [expr pow(8e-3,2)*2*asin(1)] [expr $b2/2] [expr $h2/2] [expr $h2/2] [expr -$b2/2]
layer straight $BarMatC 3 [expr pow(8e-3,2)*2*asin(1)] [expr $b2/2] [expr -$h2/2] [expr -$h2/2] [expr -$b2/2]


};
set Load [expr ($DL+$LL)] ;

puts "ahmad"
# Define Transformation
geomTransf Corotational 1 ;
geomTransf Corotational 2 ;
# Define Elements
# Columns mass
#set massCol [expr (0.30*0.30*$mConc)] ;
## Beam mass
#set massB [expr ((0.30*0.40*$mConc)+$Load)] ;
#puts "ahmad"
#
#set integration18 "HingeEndpoint 303018 0.15 303018 0.15 303018" ;
#set integration22 "HingeEndpoint 303022 0.15 303022 0.15 303022" ;
#set integration5 "HingeEndpoint 30405 0.2 30405 0.2 30405" ;
#set integration6 "HingeEndpoint 30406 0.2 30406 0.2 30406" ;
#
# Define Hyesteretic Material for SPRING
# Column 303018
# Column 303018
# Column 303018
set My_Col3030183 96864 ;# yield moment of the columns
set Mu_Col3030183 116667 ; # ultimate moment of the columns
set K_slip3030183 23921004.5 ;
#set K_slip3030183 33454545.5 ;
#

set THy_Col3030183 [expr $My_Col3030183/$K_slip3030183]; # yield chord rotation for columns of the 1st floor in rad
set THu_Col3030183 0.038196; # ultimate chord rotation for columns of the 1st floor in rad (EC8)
# Column 303022
set My_Col3030223 139969 ;# yield moment of the columns
set Mu_Col3030223 164410 ; # ultimate moment of the columns
set K_slip3030223 28279400.28 ;
set THy_Col3030223 [expr $My_Col3030223/$K_slip3030223]; # yield chord rotation for columns of the 1st floor in rad
set THu_Col3030223 0.033119; # ultimate chord rotation for columns of the 1st floor in rad (EC8)
# Column 353518
set My_Col3535183 122699 ;# yield moment of the columns
set Mu_Col3535183 153105 ; # ultimate moment of the columns
set K_slip3535183 42769567.3 ;
set THy_Col3535183 [expr $My_Col3535183/$K_slip3535183]; # yield chord rotation for columns of the 1st floor in rad
set THu_Col3535183 0.044711; # ultimate chord rotation for columns of the 1st floor in rad (EC8)
# Column353522
set My_Col3535223 176845 ;# yield moment of the columns
set Mu_Col3535223 213338 ; # ultimate moment of the columns
set K_slip3535223 45852397.1 ;
set THy_Col3535223 [expr $My_Col3535223/$K_slip3535223]; # yield chord rotation for columns of the 1st floor in rad
set THu_Col3535223 0.035585; # ultimate chord rotation for columns (EC8)
# Column404018
set My_Col4040183 150963 ;# yield moment of the columns
set Mu_Col4040183 191825 ; # ultimate moment of the columns
set K_slip4040183 60142992.8 ;
set THy_Col4040183 [expr $My_Col4040183/$K_slip4040183]; # yield chord rotation for columns of the 1st floor in rad
set THu_Col4040183 0.047679; # ultimate chord rotation for columns of the 1st floor in rad (EC8)
# Column404022

set My_Col4040223 211982 ;# yield moment of the columns
set Mu_Col4040223 266493 ; # ultimate moment of the columns
set K_slip4040223 69097658 ;
set THy_Col4040223 0.003068; # yield chord rotation for columns of the 1st floor in rad
set THu_Col4040223 0.035575; # ultimate chord rotation for columns of the 1st floor in rad (EC8)
# Column4040184
set My_Col4040184 150963 ;# yield moment of the columns
set Mu_Col4040184 191825 ; # ultimate moment of the columns
set K_slip4040184 57263162 ;
set THy_Col4040184 0.002636; # yield chord rotation for columns of the 1st floor in rad
set THu_Col4040184 0.05581; # ultimate chord rotation for columns of the 1st floor in rad (EC8)
# Column4040224
set My_Col4040224 211982 ;# yield moment of the columns
set Mu_Col4040224 266493 ; # ultimate moment of the columns
set K_slip4040224 65789050.4 ;
set THy_Col4040224 [expr $My_Col4040224/$K_slip4040224]; # yield chord rotation for columns of the 1st floor in rad
set THu_Col4040224 0.040858; # ultimate chord rotation for columns of the 1st floor in rad (EC8)
##########################################
##Beam
set My_Beam304055 93621 ;# yield moment of the columns
set Mu_Beam304055 129558 ; # ultimate moment of the columns
set K_slipBeam304055 436030898.3 ;

#set K_slipBeam304055 [expr 0.35*645150000] ;


set THy_Beam304055 [expr $My_Beam304055/$K_slipBeam304055]; # yield chord rotation for columns of the 1st floor in rad
set THu_Beam304055 0.089954; # ultimate chord rotation for columns of the 1st floor in rad (EC8)







# Define Material
set Beta 0.0 ;
# Column303018
uniaxialMaterial Hysteretic 18 $My_Col3030183 $THy_Col3030183 $Mu_Col3030183 $THu_Col3030183 [expr $My_Col3030183*(-1)] [expr $THy_Col3030183*(-1)] [expr $Mu_Col3030183*(-1)] [expr $THu_Col3030183*(-1)] 1 1 0 0 $Beta ;
#Column303022
puts "ahmad"
uniaxialMaterial Hysteretic 22 $My_Col3030223 $THy_Col3030223 $Mu_Col3030223 $THu_Col3030223 [expr $My_Col3030223*(-1)] [expr $THy_Col3030223*(-1)] [expr $Mu_Col3030223*(-1)] [expr $THu_Col3030223*(-1)] 1 1 0 0 $Beta ;
puts "ahmad"
# Column353518
#uniaxialMaterial Hysteretic 23 $My_Col353518 $THy_Col353518 $Mu_Col353518 $THu_Col353518 [expr $My_Col353518*(-1)] [expr $THy_Col353518*(-1)] [expr $Mu_Col353518*(-1)] [expr $THu_Col353518*(-1)] 1 1 0 0 $Beta ;
puts "ahmad"
# Column353522
#uniaxialMaterial Hysteretic 24 $My_Col303022 $THy_Col353522 $Mu_Col353522 $THu_Col353522 [expr $My_Col353522*(-1)] [expr $THy_Col353522*(-1)] [expr $Mu_Col353522*(-1)] [expr $THu_Col353522*(-1)] 1 1 0 0 $Beta ;
puts "ahmadb"
# Column404018
#uniaxialMaterial Hysteretic 25 $My_Col404018 $THy_Col404018 $Mu_Col404018 $THu_Col404018 [expr $My_Col404018*(-1)] [expr $THy_Col404018*(-1)] [expr $Mu_Col404018*(-1)] [expr $THu_Col404018*(-1)] 1 1 0 0 $Beta ;
puts "ahmadbc"
#Column404022
#uniaxialMaterial Hysteretic 26 $My_Col404022 $THy_Col404022 $Mu_Col404022 $THu_Col404022 -$My_Col404022 -$THy_Col404022 -$Mu_Col404022 -$THu_Col404022 1 1 0 0 $Beta ;
puts "ahmadbcd"
#Column4040184
#uniaxialMaterial Hysteretic 27 $My_Col4040184 $THy_Col4040184 $Mu_Col4040184 $THu_Col4040184 [expr $My_Col4040184*(-1)] [expr $THy_Col4040184*(-1)] [expr $Mu_Col4040184*(-1)] [expr $THu_Col4040184*(-1)] 1 1 0 0 $Beta ;
puts "ahmadbcde"
#Column4040224
#uniaxialMaterial Hysteretic 28 $My_Col4040224 $THy_Col4040224 $Mu_Col4040224 $THu_Col4040224 [expr $My_Col4040224*(-1)] [expr $THy_Col4040224*(-1)] [expr $Mu_Col4040224*(-1)] [expr $THu_Col4040224*(-1)] 1 1 0 0 $Beta ;
###########BEAM
uniaxialMaterial Hysteretic 30 $My_Beam304055 $THy_Beam304055 $Mu_Beam304055 $THu_Beam304055 [expr $My_Beam304055*(-1)] [expr $THy_Beam304055*(-1)] [expr $Mu_Beam304055*(-1)] [expr $THu_Beam304055*(-1)] 1 1 0 0 $Beta ;

#source "Spring Material.tcl"

puts "ahmad"


#
#
#
#
# Define Elements

# Columns
# First Floor

# Tag iNode jNode np SecTag TransT Mass
element nonlinearBeamColumn 1 8 11 5 303018 1 ;
element nonlinearBeamColumn 2 7 12 5 303022 1 ;
element nonlinearBeamColumn 3 6 13 5 303022 1 ;
element nonlinearBeamColumn 4 5 14 5 303018 1 ;
# Second Floor
# Tag iNode jNode np SecTag TransT Mass
element nonlinearBeamColumn 6 18 21 5 303018 1 ;
element nonlinearBeamColumn 7 17 22 5 303022 1 ;
element nonlinearBeamColumn 8 16 23 5 303022 1 ;
# Third Floor Tag iNode jNode np SecTag TransT Mass
element nonlinearBeamColumn 11 28 31 5 303018 1 ;
element nonlinearBeamColumn 12 27 32 5 303022 1 ;


# Beams
# First Floor
# Tag iNode jNode np SecT TransT Mass
element nonlinearBeamColumn 101 188 115 5 30405 2 ;
element nonlinearBeamColumn 102 115 177 5 30406 2 ;
element nonlinearBeamColumn 104 177 166 5 30406 2 ;
element nonlinearBeamColumn 105 166 135 5 30406 2 ;
element nonlinearBeamColumn 106 135 155 5 30405 2 ;
# Second Floor
# Tag iNode jNode np SecT TransT Mass
element nonlinearBeamColumn 201 288 215 5 30405 2
element nonlinearBeamColumn 202 215 277 5 30406 2 ;
element nonlinearBeamColumn 203 277 225 5 30406 2 ;
element nonlinearBeamColumn 204 225 266 5 30405 2 ;
#
## Third Floor
## Tag iNode jNode np SecT TransT Mass
element nonlinearBeamColumn 301 388 377 5 30405 2 ;
#



#Define Element ZeroLength for Rotational Springs For Columns
#First Floor
#Down
element zeroLength 21 1 8 -mat 41 -dir 6
element zeroLength 22 2 7 -mat 41 -dir 6
element zeroLength 23 3 6 -mat 41 -dir 6
element zeroLength 24 4 5 -mat 41 -dir 6
## UP
element zeroLength 25 188 11 -mat 41 -dir 6
element zeroLength 26 177 12 -mat 41 -dir 6
element zeroLength 27 166 13 -mat 41 -dir 6
element zeroLength 28 155 14 -mat 41 -dir 6
# Second Floor
# Down
element zeroLength 29 188 18 -mat 41 -dir 6
element zeroLength 30 177 17 -mat 41 -dir 6
element zeroLength 31 166 16 -mat 41 -dir 6
# UP
element zeroLength 32 288 21 -mat 41 -dir 6
element zeroLength 33 277 22 -mat 41 -dir 6
element zeroLength 34 266 23 -mat 41 -dir 6
# Third Floor
# Down
element zeroLength 15 288 28 -mat 41 -dir 6
element zeroLength 16 277 27 -mat 41 -dir 6

# UP
element zeroLength 17 388 31 -mat 41 -dir 6
element zeroLength 18 377 32 -mat 41 -dir 6

##################################################################
##element zeroLength 9911 188 123 -mat 304055 -dir 6
##element zeroLength 9912 177 1233 -mat 304055 -dir 6
##element zeroLength 9913 177 124 -mat 304055 -dir 6
##element zeroLength 9914 166 1243 -mat 304055 -dir 6
##element zeroLength 9915 166 125 -mat 304055 -dir 6
##element zeroLength 9916 155 1253 -mat 304055 -dir 6
##element zeroLength 9917 288 133 -mat 304055 -dir 6
##element zeroLength 9918 277 1333 -mat 304055 -dir 6
##element zeroLength 9919 277 134 -mat 304055 -dir 6
##element zeroLength 9920 266 1343 -mat 304055 -dir 6
###element zeroLength 9921 266 135 -mat 304055 -dir 6
###element zeroLength 9922 255 1353 -mat 304055 -dir 6
##element zeroLength 9923 388 143 -mat 304055 -dir 6
##element zeroLength 9924 377 1433 -mat 304055 -dir 6
###element zeroLength 9925 377 144 -mat 304055 -dir 6
###element zeroLength 9926 366 1443 -mat 304055 -dir 6
###element zeroLength 9927 366 145 -mat 304055 -dir 6
###element zeroLength 9928 355 1453 -mat 304055 -dir 6
#



## First Floor
equalDOF 1 8 1 2
equalDOF 2 7 1 2
equalDOF 3 6 1 2
equalDOF 4 5 1 2
equalDOF 188 11 1 2
equalDOF 177 12 1 2
equalDOF 166 13 1 2
equalDOF 155 14 1 2
#Second Floor
equalDOF 188 18 1 2
equalDOF 177 17 1 2
equalDOF 166 16 1 2
equalDOF 288 21 1 2
equalDOF 277 22 1 2
equalDOF 266 23 1 2
#Third Floor
equalDOF 288 28 1 2
equalDOF 277 27 1 2
equalDOF 388 31 1 2
equalDOF 377 32 1 2
#
#
###########################################################3


#
#
##################
#equalDOF 188 123 1 2
#equalDOF 177 1233 1 2
#equalDOF 177 124 1 2
#equalDOF 166 1243 1 2
#equalDOF 166 125 1 2
#equalDOF 155 1253 1 2
######################
#equalDOF 288 133 1 2
#equalDOF 277 1333 1 2
#equalDOF 277 134 1 2
#equalDOF 266 1343 1 2
##equalDOF 266 135 1 2
##equalDOF 255 1353 1 2
##############################
#equalDOF 388 143 1 2
#equalDOF 377 1433 1 2
##equalDOF 377 144 1 2
#equalDOF 366 1443 1 2
#equalDOF 366 145 1 2
#equalDOF 355 1453 1 2
######################################
#equalDOF 188 123 1
#equalDOF 188 1233 1
#equalDOF 188 124 1
#equalDOF 188 1243 1
#equalDOF 188 125 1
#equalDOF 188 1253 1
#####################
#equalDOF 288 133 1
#equalDOF 288 1333 1
#equalDOF 288 134 1
#equalDOF 288 1343 1
##equalDOF 288 135 1 2
##equalDOF 288 1353 1 2
#############################
#equalDOF 388 143 1 2
#equalDOF 388 1433 1 2
#equalDOF 377 144 1 2
#equalDOF 366 1443 1 2
##equalDOF 366 145 1 2
##equalDOF 355 1453 1 2
puts "end of define"
## Gravity-analysis: load-controlled static analysis

set Load [expr ($DL+$LL)] ;
pattern Plain 6 Linear { ;
eleLoad -ele 101 102 -type beamUniform -$Load
eleLoad -ele 201 202 -type beamUniform -$Load
eleLoad -ele 301 -type beamUniforn -$Load
};
puts "End of Define Loads"

set Tol 1.0e-5;
# convergence tolerance for test
constraints Penalty 10e9 10e9;
numberer RCM;
system BandGeneral;
test EnergyIncr $Tol 600;
algorithm Newton;
set NstepGravity 10;
set DGravity [expr 1./$NstepGravity];
integrator LoadControl $DGravity;
analysis Static;
analyze $NstepGravity;
#Define Loads
# Define Eigen Parameters
set a [eigen 6] ;
set W11 [lindex $a 0] ;
set W22 [lindex $a 1] ;
set W33 [lindex $a 2] ;
set W44 [lindex $a 3] ;
set W55 [lindex $a 4] ;
set W66 [lindex $a 5] ;
set W1 [expr pow($W11,0.5)] ;
set W2 [expr pow($W22,0.5)] ;
set W3 [expr pow($W33,0.5)] ;
set W4 [expr pow($W44,0.5)] ;
set W5 [expr pow($W55,0.5)] ;
set W6 [expr pow($W66,0.5)] ;
set T1 [expr 2.0*$pi/$W1] ;
set T2 [expr 2.0*$pi/$W2] ;
set T3 [expr 2.0*$pi/$W3] ;
set T4 [expr 2.0*$pi/$W4] ;
set T5 [expr 2.0*$pi/$W5] ;
set T6 [expr 2.0*$pi/$W6] ;
#
puts "*************"
puts "W1=$W1 Rad/Sec"
puts "T1=$T1 Sec"
puts "*************"
puts "W2=$W2 Rad/Sec"
puts "T2=$T2 Sec"
puts "*************"
puts "W3=$W3 Rad/Sec"
puts "T3=$T3 Sec"
puts "*************"
puts "W4=$W4 Rad/Sec"
puts "T4=$T4 Sec"
puts "*************"
puts "W5=$W5 Rad/Sec"
puts "T5=$T5 Sec"
puts "*************"
puts "W6=$W6 Rad/Sec"
puts "T6=$T6 Sec"
puts "*************"
##set Load [expr (10000)] ;
#

#


#numberer RCM
#set alphaM 1
#set alphaS 1
#constraints Penalty $alphaS $alphaM
#system BandGeneral
#integrator ArcLength 2.0 0.2;
#test EnergyIncr $Tol 600;
#
#algorithm Newton
#test NormDispIncr 1e-3 10000
#analysis Static
#analyze 100
#
#set alphaM 1
#set alphaS 1
#
# #Static Analysis
#constraints Penalty 1 1
#numberer RCM
#system BandGeneral
#test EnergyIncr 1.e-6 10
#algorithm Newton
#integrator LoadControl 0.1;
##integrator DisplacementControl 4 1 0.00025
#analysis Static
#analyze 100
##
#

[ahmadbsr]

my periods became to low 4.6e-154 can any one give me some advice?

[kesavapraba]

Dear Friends
I have once faced a similar issue with my model. I found the issue was due to improper handling of Restrained and Constrained DOFs in defining in equalDOF command though there may be other causes also. When I correctly defined them, the issue was fixed and OpenSees showed correct periods.