Eigen Analysis problem

[schoolstru]

dear all
i model 1 story 3-D building as same as the 3-D model of 3-storey example building of OpenSees wiki examples, when i use eigen analysis it gives the periods to 14, while we expect 3 modes for 1 story 3-D model when we use rigiddiapragm command, here is the model code :
# --------------------------------------------------------------------------------------------------
# Example 7. 3D RC Frame
# Silvia Mazzoni & Frank McKenna, 2006
# nonlinearBeamColumn element, inelastic fiber section
#

# SET UP ----------------------------------------------------------------------------
wipe; # clear memory of all past model definitions
model BasicBuilder -ndm 3 -ndf 6; # Define the model builder, ndm=#dimension, ndf=#dofs
set dataDir Data7st; # set up name of data directory -- remove
file mkdir $dataDir; # create data directory
file mkdir Modes;
set GMdir "../GMfiles"; # ground-motion file directory
set ViewScale 0.25; # scaling factor for viewing deformed shape, it depends on the dimensions of the model
source LibUnits.tcl; # define units
source DisplayPlane.tcl; # procedure for displaying a plane in model
source DisplayModel3D.tcl; # procedure for displaying 3D perspectives of model
source BuildRCrectSection.tcl; # procedure for definining RC fiber section

# define GEOMETRY -------------------------------------------------------------
# define structure-geometry paramters
set LCol [expr 4000]; # column height (parallel to Y axis)
set LBeam [expr 7000]; # beam length (parallel to X axis)
set LGird [expr 7000]; # girder length (parallel to Z axis)

# ------ frame configuration
set NStory 1; # number of stories above ground level
set NBay 1; # number of bays in X direction
set NBayZ 1; # number of bays in Z direction
set numModes 14;
puts "Number of Stories in Y: $NStory; Number of bays in X: $NBay; Number of bays in Z: $NBayZ"

# define NODAL COORDINATES
# calculate locations of beam/column intersections:
set X1 0.;
set X2 [expr $X1 + $LBeam];
set Y1 0.;
set Y2 [expr $Y1 + $LCol];
set Y3 [expr $Y2 + $LCol];
set Y4 [expr $Y3 + $LCol];
set Z1 0.0;
set Z2 [expr $Z1 + $LGird];

node 111 $X1 $Y1 $Z1; # frame 1
node 112 $X2 $Y1 $Z1;
node 121 $X1 $Y2 $Z1;
node 122 $X2 $Y2 $Z1;
#node 131 $X1 $Y3 $Z1;
#node 132 $X2 $Y3 $Z1;
#node 141 $X1 $Y4 $Z1;
#node 142 $X2 $Y4 $Z1;
node 211 $X1 $Y1 $Z2; # frame 2
node 212 $X2 $Y1 $Z2;
node 221 $X1 $Y2 $Z2;
node 222 $X2 $Y2 $Z2;
#node 231 $X1 $Y3 $Z2;
##node 232 $X2 $Y3 $Z2;
#node 241 $X1 $Y4 $Z2;
#node 242 $X2 $Y4 $Z2;
#

# define Rigid Floor Diaphragm
set RigidDiaphragm ON ; # options: ON, OFF. specify this before the analysis parameters are set the constraints are handled differently.
set Xa [expr ($X2+$X1)/2]; # mid-span coordinate for rigid diaphragm
set Za [expr ($Z2+$Z1)/2];
# rigid-diaphragm nodes in center of each diaphram
set RigidDiaphragm ON ; # this communicates to the analysis parameters that I will be using rigid diaphragms
node 1121 $Xa $Y2 $Za; # master nodes for rigid diaphragm -- story 2, bay 1, frame 1-2
#node 1131 $Xa $Y3 $Za; # master nodes for rigid diaphragm -- story 3, bay 1, frame 1-2
#node 1141 $Xa $Y4 $Za; # master nodes for rigid diaphragm -- story 4, bay 1, frame 1-2
## Constraints for rigid diaphragm master nodes
fix 1121 0 1 0 1 0 1
#fix 1131 0 1 0 1 0 1
#fix 1141 0 1 0 1 0 1
## ------------------------define Rigid Diaphram, dof 2 is normal to floor
set perpDirn 2;
rigidDiaphragm $perpDirn 1121 121 122 221 222; # level 2
#rigidDiaphragm $perpDirn 1131 131 132 231 232; # level 3
#rigidDiaphragm $perpDirn 1141 141 142 241 242; # level 4
#
# determine support nodes where ground motions are input, for multiple-support excitation
set iSupportNode "111 112 211 212"

# BOUNDARY CONDITIONS
fixY 0 1 1 1 1 1 1; # pin all Y=0.0 nodes

# calculated MODEL PARAMETERS, particular to this model
# Set up parameters that are particular to the model for displacement control
set IDctrlNode 141; # node where displacement is read for displacement control
set IDctrlDOF 1; # degree of freedom of displacement read for displacement control
set LBuilding [expr $Y4]; # total building height

# Define SECTIONS -------------------------------------------------------------
set SectionType Elastic ; # options: Elastic FiberSection
#set SectionType Elastic ; # options: Elastic FiberSection

# define section tags:
set ColSecTag 1
set BeamSecTag 2
set GirdSecTag 3
set ColSecTagFiber 4
set BeamSecTagFiber 5
set GirdSecTagFiber 6
set SecTagTorsion 70

# Section Properties:
set HCol [expr 750]; # square-Column width
set BCol $HCol
set HBeam [expr 600]; # Beam depth -- perpendicular to bending axis
set BBeam [expr 450]; # Beam width -- parallel to bending axis
set HGird [expr 600]; # Girder depth -- perpendicular to bending axis
set BGird [expr 450]; # Girder width -- parallel to bending axis

if {$SectionType == "Elastic"} {
# material properties:
set fc 28; # concrete nominal compressive strength
set Ec [expr 4700*pow($fc,0.5)]; # concrete Young's Modulus
set nu 0.2; # Poisson's ratio
set Gc [expr $Ec/2./[expr 1+$nu]]; # Torsional stiffness Modulus
set J $Ubig; # set large torsional stiffness
# column section properties:
set AgCol [expr $HCol*$BCol]; # rectuangular-Column cross-sectional area
set IzCol [expr 0.5*1./12*$BCol*pow($HCol,3)]; # about-local-z Rect-Column gross moment of inertial
set IyCol [expr 0.5*1./12*$HCol*pow($BCol,3)]; # about-local-z Rect-Column gross moment of inertial
# beam sections:
set AgBeam [expr $HBeam*$BBeam]; # rectuangular-Beam cross-sectional area
set IzBeam [expr 0.5*1./12*$BBeam*pow($HBeam,3)]; # about-local-z Rect-Beam cracked moment of inertial
set IyBeam [expr 0.5*1./12*$HBeam*pow($BBeam,3)]; # about-local-y Rect-Beam cracked moment of inertial
# girder sections:
set AgGird [expr $HGird*$BGird]; # rectuangular-Girder cross-sectional area
set IzGird [expr 0.5*1./12*$BGird*pow($HGird,3)]; # about-local-z Rect-Girder cracked moment of inertial
set IyGird [expr 0.5*1./12*$HGird*pow($BGird,3)]; # about-local-y Rect-Girder cracked moment of inertial

section Elastic $ColSecTag $Ec $AgCol $IzCol $IyCol $Gc $J
section Elastic $BeamSecTag $Ec $AgBeam $IzBeam $IyBeam $Gc $J
section Elastic $GirdSecTag $Ec $AgGird $IzGird $IyGird $Gc $J

set IDconcCore 1; # material numbers for recorder (this stressstrain recorder will be blank, as this is an elastic section)
set IDSteel 2; # material numbers for recorder (this stressstrain recorder will be blank, as this is an elastic section)

} elseif {$SectionType == "FiberSection"} {
# MATERIAL parameters
source LibMaterialsRC.tcl; # define library of Reinforced-concrete Materials

# FIBER SECTION properties
# Column section geometry:
set cover [expr 2.5*$in]; # rectangular-RC-Column cover
set numBarsTopCol 8; # number of longitudinal-reinforcement bars on top layer
set numBarsBotCol 8; # number of longitudinal-reinforcement bars on bottom layer
set numBarsIntCol 6; # TOTAL number of reinforcing bars on the intermediate layers
set barAreaTopCol [expr 1.*$in*$in]; # longitudinal-reinforcement bar area
set barAreaBotCol [expr 1.*$in*$in]; # longitudinal-reinforcement bar area
set barAreaIntCol [expr 1.*$in*$in]; # longitudinal-reinforcement bar area

set numBarsTopBeam 6; # number of longitudinal-reinforcement bars on top layer
set numBarsBotBeam 6; # number of longitudinal-reinforcement bars on bottom layer
set numBarsIntBeam 2; # TOTAL number of reinforcing bars on the intermediate layers
set barAreaTopBeam [expr 1.*$in*$in]; # longitudinal-reinforcement bar area
set barAreaBotBeam [expr 1.*$in*$in]; # longitudinal-reinforcement bar area
set barAreaIntBeam [expr 1.*$in*$in]; # longitudinal-reinforcement bar area

set numBarsTopGird 6; # number of longitudinal-reinforcement bars on top layer
set numBarsBotGird 6; # number of longitudinal-reinforcement bars on bottom layer
set numBarsIntGird 2; # TOTAL number of reinforcing bars on the intermediate layers
set barAreaTopGird [expr 1.*$in*$in]; # longitudinal-reinforcement bar area
set barAreaBotGird [expr 1.*$in*$in]; # longitudinal-reinforcement bar area
set barAreaIntGird [expr 1.*$in*$in]; # longitudinal-reinforcement bar area

set nfCoreY 20; # number of fibers in the core patch in the y direction
set nfCoreZ 20; # number of fibers in the core patch in the z direction
set nfCoverY 20; # number of fibers in the cover patches with long sides in the y direction
set nfCoverZ 20; # number of fibers in the cover patches with long sides in the z direction
# rectangular section with one layer of steel evenly distributed around the perimeter and a confined core.
BuildRCrectSection $ColSecTagFiber $HCol $BCol $cover $cover $IDconcCore $IDconcCover $IDSteel $numBarsTopCol $barAreaTopCol $numBarsBotCol $barAreaBotCol $numBarsIntCol $barAreaIntCol $nfCoreY $nfCoreZ $nfCoverY $nfCoverZ
BuildRCrectSection $BeamSecTagFiber $HBeam $BBeam $cover $cover $IDconcCore $IDconcCover $IDSteel $numBarsTopBeam $barAreaTopBeam $numBarsBotBeam $barAreaBotBeam $numBarsIntBeam $barAreaIntBeam $nfCoreY $nfCoreZ $nfCoverY $nfCoverZ
BuildRCrectSection $GirdSecTagFiber $HGird $BGird $cover $cover $IDconcCore $IDconcCover $IDSteel $numBarsTopGird $barAreaTopGird $numBarsBotGird $barAreaBotGird $numBarsIntGird $barAreaIntGird $nfCoreY $nfCoreZ $nfCoverY $nfCoverZ

# assign torsional Stiffness for 3D Model
uniaxialMaterial Elastic $SecTagTorsion $Ubig
section Aggregator $ColSecTag $SecTagTorsion T -section $ColSecTagFiber
section Aggregator $BeamSecTag $SecTagTorsion T -section $BeamSecTagFiber
section Aggregator $GirdSecTag $SecTagTorsion T -section $GirdSecTagFiber
} else {
puts "No section has been defined"
return -1
}
set GammaConcrete [expr 25000*1.e-9]; # Reinforced-Concrete weight density (weight per volume)
set QdlCol [expr $GammaConcrete*$HCol*$BCol]; # self weight of Column, weight per length
set QBeam [expr $GammaConcrete*$HBeam*$BBeam]; # self weight of Beam, weight per length
set QGird [expr $GammaConcrete*$HGird*$BGird]; # self weight of Gird, weight per length

# define ELEMENTS -------------------------------------------------------
# set up geometric transformations of element
# separate columns and beams, in case of P-Delta analysis for columns
# in 3D model, assign vector vecxz
set IDColTransf 1; # all columns
set IDBeamTransf 2; # all beams
set IDGirdTransf 3; # all girders
set ColTransfType Linear ; # options, Linear PDelta Corotational
geomTransf $ColTransfType $IDColTransf 0 0 1 ; # only columns can have PDelta effects (gravity effects)
geomTransf Linear $IDBeamTransf 0 0 1
geomTransf Linear $IDGirdTransf 1 0 0

# Define Beam-Column Elements
set np 5; # number of Gauss integration points for nonlinear curvature distribution

# Frame 1
# columns
element nonlinearBeamColumn 1111 111 121 $np $ColSecTag $IDColTransf; # level 1-2
element nonlinearBeamColumn 1112 112 122 $np $ColSecTag $IDColTransf;
#element nonlinearBeamColumn 1121 121 131 $np $ColSecTag $IDColTransf; # level 2-3
#element nonlinearBeamColumn 1122 122 132 $np $ColSecTag $IDColTransf
#element nonlinearBeamColumn 1131 131 141 $np $ColSecTag $IDColTransf; # level 3-4
#element nonlinearBeamColumn 1132 132 142 $np $ColSecTag $IDColTransf
## beams
element nonlinearBeamColumn 1221 121 122 $np $BeamSecTag $IDBeamTransf; # level 2
#element nonlinearBeamColumn 1231 131 132 $np $BeamSecTag $IDBeamTransf; # level 3
#element nonlinearBeamColumn 1241 141 142 $np $BeamSecTag $IDBeamTransf; # level 4
#
## Frame 2
# columns
element nonlinearBeamColumn 2111 211 221 $np $ColSecTag $IDColTransf; # level 1-2
element nonlinearBeamColumn 2112 212 222 $np $ColSecTag $IDColTransf
#element nonlinearBeamColumn 2121 221 231 $np $ColSecTag $IDColTransf; # level 2-3
#element nonlinearBeamColumn 2122 222 232 $np $ColSecTag $IDColTransf
#element nonlinearBeamColumn 2131 231 241 $np $ColSecTag $IDColTransf; # level 3-4
#element nonlinearBeamColumn 2132 232 242 $np $ColSecTag $IDColTransf
## beams
element nonlinearBeamColumn 2221 221 222 $np $BeamSecTag $IDBeamTransf; # level 2
#element nonlinearBeamColumn 2231 231 232 $np $BeamSecTag $IDBeamTransf; # level 3
#element nonlinearBeamColumn 2241 241 242 $np $BeamSecTag $IDBeamTransf; # level 4
#
# girders connecting frames
# Frame 1-2
element nonlinearBeamColumn 1321 121 221 $np $GirdSecTag $IDGirdTransf; # level 2
element nonlinearBeamColumn 1322 122 222 $np $GirdSecTag $IDGirdTransf;
#element nonlinearBeamColumn 1331 131 231 $np $GirdSecTag $IDGirdTransf; # level 3
#element nonlinearBeamColumn 1332 132 232 $np $GirdSecTag $IDGirdTransf;
#element nonlinearBeamColumn 1341 141 241 $np $GirdSecTag $IDGirdTransf; # level 4
#element nonlinearBeamColumn 1342 142 242 $np $GirdSecTag $IDGirdTransf;
#

# --------------------------------------------------------------------------------------------------------------------------------
# Define GRAVITY LOADS, weight and masses
# calculate dead load of frame, assume this to be an internal frame (do LL in a similar manner)
# calculate distributed weight along the beam length
set Tslab [expr 150]; # 6-inch slab
set Lslab [expr $LGird/2]; # slab extends a distance of $LGird/2 in/out of plane
set DLfactor 1.0; # scale dead load up a little
set Qslab [expr $GammaConcrete*$Tslab*$Lslab*$DLfactor];
set QdlBeam [expr $Qslab + $QBeam]; # dead load distributed along beam (one-way slab)
set QdlGird $QGird; # dead load distributed along girder
set WeightCol [expr $QdlCol*$LCol]; # total Column weight
set WeightBeam [expr $QdlBeam*$LBeam]; # total Beam weight
set WeightGird [expr $QdlGird*$LGird]; # total Beam weight

# assign masses to the nodes that the columns are connected to
# each connection takes the mass of 1/2 of each element framing into it (mass=weight/$g)
set Mmid [expr ($WeightCol/2 + $WeightCol/2 +$WeightBeam/2+$WeightGird/2)/9810];
set Mtop [expr ($WeightCol/2 + $WeightBeam/2+$WeightGird/2)/$g];
set Mmid2 39.6724;

# frame 1
mass 121 16.25 1.0e-9 16.25 1.0e-9 1.0e-9 1.0e-9; # level 2
mass 122 16.25 1.0e-9 16.25 1.0e-9 1.0e-9 1.0e-9;
#mass 131 $Mmid 0 $Mmid 0. 0. 0.; # level 3
#mass 132 $Mmid 0 $Mmid 0. 0. 0.;
#mass 141 $Mtop 0 $Mtop 0. 0. 0.; # level 4
#mass 142 $Mtop 0 $Mtop 0. 0. 0.;
#
# frame 2
mass 221 16.25 1.0e-9 16.25 1.0e-9 1.0e-9 1.0e-9; # level 2
mass 222 16.25 1.0e-9 16.25 1.0e-9 1.0e-9 1.0e-9;
#mass 231 $Mmid 0 $Mmid 0. 0. 0.; # level 3
#mass 232 $Mmid 0 $Mmid 0. 0. 0.;
#mass 241 $Mtop 0 $Mtop 0. 0. 0.; # level 4
#mass 242 $Mtop 0 $Mtop 0. 0. 0.;
#
set FloorWeight2 [expr 4*$WeightCol + 2*$WeightGird + 2*$WeightBeam]
set FloorWeight3 [expr 4*$WeightCol + 2*$WeightGird + 2*$WeightBeam]
set FloorWeight4 [expr 2*$WeightCol + 2*$WeightGird + 2*$WeightBeam]
set WeightTotal [expr $FloorWeight2+$FloorWeight3+$FloorWeight4]; # total building weight
set MassTotal [expr $WeightTotal/$g]; # total building mass

# --------------------------------------------------------------------------------------------------------------------------------
# LATERAL-LOAD distribution for static pushover analysis
# calculate distribution of lateral load based on mass/weight distributions along building height
# Fj = WjHj/sum(WiHi) * Weight at each floor j
set sumWiHi [expr $FloorWeight2*$Y2+$FloorWeight3*$Y3+$FloorWeight4*$Y4]; # sum of storey weight times height, for lateral-load distribution
set WiHi2 [expr $FloorWeight2*$Y2]; # storey weight times height, for lateral-load distribution
set WiHi3 [expr $FloorWeight3*$Y3]; # storey weight times height, for lateral-load distribution
set WiHi4 [expr $FloorWeight4*$Y4]; # storey weight times height, for lateral-load distribution
set F2 [expr $WiHi2/$sumWiHi*$WeightTotal]; # lateral load at level
set F3 [expr $WiHi3/$sumWiHi*$WeightTotal]; # lateral load at level
set F4 [expr $WiHi4/$sumWiHi*$WeightTotal]; # lateral load at level

puts "before Recorder";
# Define RECORDERS -------------------------------------------------------------
recorder Node -file $dataDir/DFree.out -time -node 141 -dof 1 2 3 disp; # displacements of free node
recorder Node -file $dataDir/DBase.out -time -node 111 112 211 212 -dof 1 2 3 disp; # displacements of support nodes
recorder Node -file $dataDir/RBase.out -time -node 111 112 211 212 -dof 1 2 3 reaction; # support reaction
#recorder Drift -file $dataDir/DrNode.out -time -iNode 111 -jNode 141 -dof 1 -perpDirn 2; # lateral drift
recorder Element -file $dataDir/Fel1.out -time -ele 1111 localForce; # element forces in local coordinates
recorder Element -xml $dataDir/PlasticRotation1.out -time -ele 1111 plasticRotation; # element forces in local coordinates
recorder Element -file $dataDir/ForceEle1sec1.out -time -ele 1111 section 1 force; # section forces, axial and moment, node i
recorder Element -file $dataDir/DefoEle1sec1.out -time -ele 11111 section 1 deformation; # section deformations, axial and curvature, node i
recorder Element -file $dataDir/ForceEle1sec$np.out -time -ele 111 section $np force; # section forces, axial and moment, node j
recorder Element -file $dataDir/DefoEle1sec$np.out -time -ele 1111 section $np deformation; # section deformations, axial and curvature, node j
#set yFiber [expr $HCol/2-$cover]; # fiber location for stress-strain recorder, local coords
#set zFiber [expr $BCol/2-$cover]; # fiber location for stress-strain recorder, local coords
#recorder Element -file $dataDir/SSconcEle1sec1.out -time -ele 1111 section $np fiber $yFiber $zFiber $IDconcCore stressStrain; # steel fiber stress-strain, node i
#recorder Element -file $dataDir/SSreinfEle1sec1.out -time -ele 1111 section $np fiber $yFiber $zFiber $IDSteel stressStrain; # steel fiber stress-strain, node i
set lambda [eigen $numModes]
puts "$lambda"
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 "IzCol is $IzCol IyCol is $IyCol"
puts "Mmid is $Mmid"
puts "$T"
puts "HCol is $HCol";
puts "BCol is $HCol";
puts "HBeam is $HBeam"; # Beam depth -- perpendicular to bending axis
puts "BBeam is $BBeam"; # Beam width -- parallel to bending axis
puts "HGird is $HGird"; # Girder depth -- perpendicular to bending axis
puts "BGird is $BGird"; # Girder width -- parallel to bending axis
puts "Ec is $Ec"
puts "IzBeam is $IzBeam"
puts "LCol is $LCol"
puts "Omega^2 DOF1 [expr 4*12*$Ec*$IzBeam/pow($LCol,3)/(65)]"
puts "1st mode period [expr 2*$PI/sqrt(4*12*$Ec*$IzBeam/pow($LCol,3)/(65))]"
puts "1st mode period [expr 2*$PI/sqrt(4*12*$Ec*$IzBeam/pow($LCol,3)/(4*$Mmid2))]"

puts "Before Display";
# Define DISPLAY -------------------------------------------------------------
#set xPixels 1200; # height of graphical window in pixels
#set yPixels 800; # height of graphical window in pixels
#set xLoc1 10; # horizontal location of graphical window (0=upper left-most corner)
#set yLoc1 10; # vertical location of graphical window (0=upper left-most corner)
#set dAmp 2; # scaling factor for viewing deformed shape, it depends on the dimensions of the model
#DisplayModel3D NodeNumbers $dAmp $xLoc1 $yLoc1 $xPixels $yPixels;
#puts "After Display"
#
# define GRAVITY -------------------------------------------------------------
# GRAVITY LOADS # define gravity load applied to beams and columns -- eleLoad applies loads in local coordinate axis
pattern Plain 101 Linear {
# Frame 1
# columns
eleLoad -ele 1111 -type -beamUniform 0. 0. -$QdlCol; # level 1-2
eleLoad -ele 1112 -type -beamUniform 0. 0. -$QdlCol
# eleLoad -ele 1121 -type -beamUniform 0. 0. -$QdlCol; # level 2-3
# eleLoad -ele 1122 -type -beamUniform 0. 0. -$QdlCol
# eleLoad -ele 1131 -type -beamUniform 0. 0. -$QdlCol; # level 3-4
# eleLoad -ele 1132 -type -beamUniform 0. 0. -$QdlCol
## beams
eleLoad -ele 1221 -type -beamUniform -$QdlBeam 0.; # level 2
# eleLoad -ele 1231 -type -beamUniform -$QdlBeam 0.; # level 3
# eleLoad -ele 1241 -type -beamUniform -$QdlBeam 0.; # level 4
#
# Frame 2
# columns
eleLoad -ele 2111 -type -beamUniform 0. 0. -$QdlCol; # level 1-2
eleLoad -ele 2112 -type -beamUniform 0. 0. -$QdlCol
# eleLoad -ele 2121 -type -beamUniform 0. 0. -$QdlCol; # level 2-3
# eleLoad -ele 2122 -type -beamUniform 0. 0. -$QdlCol
# eleLoad -ele 2131 -type -beamUniform 0. 0. -$QdlCol; # level 3-4
# eleLoad -ele 2132 -type -beamUniform 0. 0. -$QdlCol
## beams
eleLoad -ele 2221 -type -beamUniform -$QdlBeam 0.; # level 2
# eleLoad -ele 2231 -type -beamUniform -$QdlBeam 0.; # level 3
# eleLoad -ele 2241 -type -beamUniform -$QdlBeam 0.; # level 4
#
# girders connecting frames
# Frame 1-2
eleLoad -ele 1321 -type -beamUniform -$QdlGird 0.; # level 2
eleLoad -ele 1322 -type -beamUniform -$QdlGird 0.;
# eleLoad -ele 1331 -type -beamUniform -$QdlGird 0.; # level 3
# eleLoad -ele 1332 -type -beamUniform -$QdlGird 0.;
# eleLoad -ele 1341 -type -beamUniform -$QdlGird 0.; # level 4
# eleLoad -ele 1342 -type -beamUniform -$QdlGird 0.;
}

# Gravity-analysis parameters -- load-controlled static analysis
set Tol 1.0e-8; # convergence tolerance for test
variable constraintsTypeGravity Plain; # default;
if { [info exists RigidDiaphragm] == 1} {
if {$RigidDiaphragm=="ON"} {
variable constraintsTypeGravity Lagrange; # large model: try Transformation
}; # if rigid diaphragm is on
}; # if rigid diaphragm exists
constraints $constraintsTypeGravity ; # how it handles boundary conditions
numberer RCM; # renumber dof's to minimize band-width (optimization), if you want to
system BandGeneral ; # how to store and solve the system of equations in the analysis (large model: try UmfPack)
test EnergyIncr $Tol 6 ; # determine if convergence has been achieved at the end of an iteration step
algorithm Newton; # use Newton's solution algorithm: updates tangent stiffness at every iteration
set NstepGravity 10; # apply gravity in 2000 steps
set DGravity [expr 1./$NstepGravity]; # first load increment;
integrator LoadControl $DGravity; # determine the next time step for an analysis
analysis Static; # define type of analysis static or transient
analyze $NstepGravity; # apply gravity

#
# ------------------------------------------------- maintain constant gravity loads and reset time to zero
#loadConst -time 0.0
set Tol 1.0e-6; # reduce tolerance after gravity loads
puts "Model Built"

[fmk]

could you please specify what exactly the problem is.

[schoolstru]

Dear fmk
how can we justify this contradiction that for 1-story 3-D model with rigid diaphragm we expect 3 periods based on structural dynamics while the openssees gave 14 periods for this model?!

[schoolstru]

I have modelled a 1-story building similar to the examples in OpenSees wiki. Surprisingly the software reports 14 periods for this model while I expect only three peiods since this is a 3 degree of freedom system (floors are modelled as rigid diphtagms).