about period

[mjahmadian]

hello

I modelling a three story frame.from opensees period of mode 1 is 1.33.when use other software give period much less

this is my model:

# units kg,m

wipe
loadConst -time 0.0

# NUMBER OF DIMENTION AND DEGREES OF FREEDOM

model basic -ndm 2 -ndf 3

# define nod
node 1 0 0
node 2 5 0
node 3 8 0
node 4 12 0

node 5 0 3
node 6 5 3
node 7 8 3
node 8 12 3

node 9 0 6
node 10 5 6
node 11 8 6
node 12 12 6

node 13 0 9
node 14 5 9
node 15 8 9
node 16 12 9


fix 1 1 1 1
fix 2 1 1 1
fix 3 1 1 1
fix 4 1 1 1


equalDOF 5 6 1
equalDOF 6 7 1
equalDOF 7 8 1

equalDOF 9 10 1
equalDOF 10 11 1
equalDOF 11 12 1

equalDOF 13 14 1
equalDOF 14 15 1
equalDOF 15 16 1


#uniaxialMaterial Steel02 $matTag $Fy $E $b $R0 $cR1 $cR2 $a1 $a2 $a3 $a4
uniaxialMaterial Steel02 1 275000000 199900000000 0.03 20 0.925 0.15


mass 5 [expr (490+0.2*245)*5*10] 0.000001 0
mass 8 [expr (490+0.2*245)*5*10] 0.000001 0
mass 9 [expr (490+0.2*245)*5*10] 0.000001 0
mass 12 [expr (490+0.2*245)*5*10] 0.000001 0
mass 13 [expr (490+0.2*245)*5*10] 0.000001 0
mass 16 [expr (490+0.2*245)*5*10] 0.000001 0


proc Wsection { secID matID d tw bf tf nfdw nftw nfbf nftf} {
# ###################################################################
# Wsection $secID $matID $d $bf $tf $tw $nfdw $nftw $nfbf $nftf
# ###################################################################
# create a standard W section given the nominal section properties
# written: Remo M. de Souza
# date: 06/99
# modified: 08/99 (according to the new general modelbuilder)
# input parameters
# secID - section ID number
# matID - material ID number
# d = nominal depth
# tw = web thickness
# bf = flange width
# tf = flange thickness
# nfdw = number of fibers along web depth
# nftw = number of fibers along web thickness
# nfbf = number of fibers along flange width
# nftf = number of fibers along flange thickness

set dw [expr $d - 2 * $tf]
set y1 [expr -$d/2]
set y2 [expr -$dw/2]
set y3 [expr $dw/2]
set y4 [expr $d/2]

set z1 [expr -$bf/2]
set z2 [expr -$tw/2]
set z3 [expr $tw/2]
set z4 [expr $bf/2]

section fiberSec $secID {
# nfIJ nfJK yI zI yJ zJ yK zK yL zL
patch quadr $matID $nfbf $nftf $y1 $z4 $y1 $z1 $y2 $z1 $y2 $z4
patch quadr $matID $nftw $nfdw $y2 $z3 $y2 $z2 $y3 $z2 $y3 $z3
patch quadr $matID $nfbf $nftf $y3 $z4 $y3 $z1 $y4 $z1 $y4 $z4
}
}

##################### Model section #####################
### ipe 240
#tag matID d tw bf tf nfdw nftw nfbf nftf
Wsection 1 1 0.24 0.0062 0.12 0.0098 12 4 12 4





geomTransf PDelta 1
geomTransf Linear 2




###################### Define Element ##########################

#Cloumns ############## define nolinear column


element nonlinearBeamColumn 1 1 5 5 1 1
element nonlinearBeamColumn 2 2 6 5 1 1
element nonlinearBeamColumn 3 3 7 5 1 1

element nonlinearBeamColumn 4 4 8 5 1 1
element nonlinearBeamColumn 5 5 9 5 1 1
element nonlinearBeamColumn 6 6 10 5 1 1

element nonlinearBeamColumn 7 7 11 5 1 1
element nonlinearBeamColumn 8 8 12 5 1 1
element nonlinearBeamColumn 9 9 13 5 1 1
element nonlinearBeamColumn 10 10 14 5 1 1
element nonlinearBeamColumn 11 11 15 5 1 1
element nonlinearBeamColumn 12 12 16 5 1 1

#BEAMS ############## define nolinear BEAMS
# element nonlinearBeamColumn $eleTag $iNode $jNode $numIntgrPts $secTag $transfTag <-mass $massDens>



element nonlinearBeamColumn 13 5 6 5 1 2
element nonlinearBeamColumn 14 6 7 5 1 2
element nonlinearBeamColumn 15 7 8 5 1 2

element nonlinearBeamColumn 16 9 10 5 1 2
element nonlinearBeamColumn 17 10 11 5 1 2
element nonlinearBeamColumn 18 11 12 5 1 2


element nonlinearBeamColumn 19 13 14 5 1 2
element nonlinearBeamColumn 20 14 15 5 1 2
element nonlinearBeamColumn 21 15 16 5 1 2




puts " END OF MODEL GENERATION "



set GravSteps 10

constraints Plain;
numberer RCM; # renumber dof's to minimize band-width
system UmfPack;
test EnergyIncr 1.0e-8 10 1
algorithm KrylovNewton
integrator LoadControl 0.01
analysis Static
analyze $GravSteps
puts "Gravity Analyze Perform Successfully..."


set pi 3.14
set autoval [eigen 4]
puts "
EIGEN VALUES: $autoval"
set T1 [expr 2*$pi/pow([lindex $autoval 0],.5)]
set T2 [expr 2*$pi/pow([lindex $autoval 1],.5)]
set T3 [expr 2*$pi/pow([lindex $autoval 2],.5)]
set T4 [expr 2*$pi/pow([lindex $autoval 3],.5)]

puts "PERIODS: $T1 , $T2 , $T3 , $T4
* Finished Eigen Analysis After Gravity Anlalyze... *
"


PLEASE HELP ME

thanks alot.

[susan]

most probably the mass source in two programs are different.