stiffness in zero-length element

[solmaz_moradpoor]

hi silvia
do we can define stiffness in zero-length element?

[fmk]

you provide a uniaxial material which the force-deformation response (not the typical stress-strain response if the material was in a truss or a section in a beam-column element)

[solmaz_moradpoor]

Thanks for your help

[solmaz_moradpoor]

hi
i provide a uniaxial material.i put stiffness instead $E.but i dont know what put instead $Fy.

uniaxialMaterial Steel02 $matTag $Fy $E $b

[fmk]

if this is going into a zero length element you put the YIELD FORCE HERE

[solmaz_moradpoor]

hi
can we define 2 zeroLength element in one node?

[fmk]

why don't you try it before you ask?? .. but yes you can.

[solmaz_moradpoor]

you say right i should try first
dear fmk my problem in define stiffness in zero-length element didnt solve
i use nDMaterial instead uniaxialMaterial and i put element zeroLengthND in my scripts.but when i run model opensees gives this message
element zeroLengthND is no longer available,please use the zeroLength section element instead
i send my scripts for you:

wipe
model BasicBuilder -ndm 2 -ndf 3;

set m 1;
set kg 1;
set sec 1;
set sec2 [expr $sec*$sec];
set m2 [expr $m*$m];
set g [expr 9.81*$m/$sec2];
set ubig 1e10;
set usmall [expr 1/$ubig];
#create nodes
#node nodetag x y

node 1 0.0 0.0
node 2 0.0 3.96
node 3 0.0 7.92
node 4 0.0 11.88

node 5 9.15 0.0
node 6 9.15 3.96
node 7 9.15 7.92
node 8 9.15 11.88

node 9 18.3 0.0
node 10 18.3 3.96
node 11 18.3 7.92
node 12 18.3 11.88
node 122 18.3 11.88

node 13 27.45 0.0
node 14 27.45 3.96
node 15 27.45 7.92
node 16 27.45 11.88

node 17 36.6 0.0
node 18 36.6 3.96
node 19 36.6 7.92
node 20 36.6 11.88

#nodes for pinned connection

node 140 27.45 3.96
node 150 27.45 7.92
node 160 27.45 11.88

node 180 36.6 3.96
node 190 36.6 7.92
node 200 36.6 11.88

fix 1 1 1 1
fix 5 1 1 1
fix 9 1 1 1
fix 13 1 1 1
fix 17 1 1 1

#applying pinned connection

equalDOF 14 140 1 2
equalDOF 15 150 1 2
equalDOF 16 160 1 2
equalDOF 18 180 1 2
equalDOF 19 190 1 2
equalDOF 20 200 1 2
#
equalDOF 12 122 1 2

#
equalDOF 10 2 1
equalDOF 10 6 1
equalDOF 10 14 1
equalDOF 10 18 1
#
equalDOF 11 3 1
equalDOF 11 7 1
equalDOF 11 15 1
equalDOF 11 19 1
#
equalDOF 12 4 1
equalDOF 12 8 1
equalDOF 12 16 1
equalDOF 12 20 1
#


# #########################################################
set Fy1 [expr 35107570.2*$kg/$m2];
set Fy2 [expr 25277450.5*$kg/$m2];
set E [expr 20600000000*$kg/$m2];

set b 0.02;
set steel 1;
set ssteel 2;

uniaxialMaterial Steel01 $steel $Fy1 $E $b; #for bilinear
uniaxialMaterial Steel01 $ssteel $Fy2 $E $b;

set m1 48760.5;
set m2 52756.30;
mass 10 $m1 0.1 0.0
mass 11 $m1 0.1 0.0
mass 12 $m2 0.1 0.0

#an extra mass because of software limitation to facalitate a
mass 8 0.1 0.1 0.0

set Weight1 [expr $m1*$kg*$g];
set Weight2 [expr $m2*$kg*$g];
proc Wsection { secID matID d bf tf tw nfdw nftw nfbf nftf} {
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
}
}

puts "$$*$$"

# Wsection $seciD $matiD $d $bf $tf $tw $nfdw $nftw $nfbf $nftf

# W14X257
Wsection 1 1 0.4166 0.4064 0.048 0.03 12 4 12 4
# W14X311
Wsection 2 1 0.4343 0.4115 0.0574 0.0358 12 4 12 4
# W33X118
Wsection 3 2 0.8357 0.2921 0.0188 0.014 12 4 12 4
# W30X116
Wsection 4 2 0.762 0.2667 0.0216 0.0144 12 4 12 4
# W24X68
Wsection 5 2 0.602 0.2278 0.0149 0.0105 12 4 12 4

geomTransf PDelta 1
geomTransf Linear 2

#element dispBeamColumn $eleTag $iNode $iNode $numintgrPts $secTag $transfTag <-mass $massDens>

# define nolinear column first row
# #########################################################
element dispBeamColumn 1 1 2 5 1 1
element dispBeamColumn 2 2 3 5 1 1
element dispBeamColumn 3 3 4 5 1 1
##########################################################
# define nolinear column second row
# #########################################################
element dispBeamColumn 4 5 6 5 2 1
element dispBeamColumn 5 6 7 5 2 1
element dispBeamColumn 6 7 8 5 2 1

# #########################################################
# define nolinear column 3rd row
# #########################################################
element dispBeamColumn 7 9 10 5 2 1
element dispBeamColumn 8 10 11 5 2 1
element dispBeamColumn 9 11 12 5 2 1

# #########################################################
# define nolinear column 4th row
# #########################################################
element dispBeamColumn 10 13 14 5 2 1
element dispBeamColumn 11 14 15 5 2 1
element dispBeamColumn 12 15 16 5 2 1

# #########################################################
# define nolinear column 5th row
# #########################################################
element dispBeamColumn 13 17 18 5 1 1
element dispBeamColumn 14 18 19 5 1 1
element dispBeamColumn 15 19 20 5 1 1
# Beam
# define nonlinear beams 1st floor
# #########################################################
element dispBeamColumn 16 2 6 5 3 2
element dispBeamColumn 17 6 10 5 3 2
element dispBeamColumn 18 10 14 5 3 2
element dispBeamColumn 19 140 180 5 3 2
# #########################################################
# define nolinear beams 2nd floor
# #########################################################
element dispBeamColumn 20 3 7 5 4 2
element dispBeamColumn 21 7 11 5 4 2
element dispBeamColumn 22 11 15 5 4 2
element dispBeamColumn 23 150 190 5 4 2
# #########################################################
# define nolinear beams 3rd floor
# #########################################################
element dispBeamColumn 24 4 8 5 5 2
element dispBeamColumn 25 8 12 5 5 2
element dispBeamColumn 26 12 16 5 5 2
element dispBeamColumn 27 160 200 5 5 2

puts "*"

set K 47338.2;

#nDMaterial ElasticIsotropic $matTag $E $v

nDMaterial ElasticIsotropic 3 $K 0;

#element zeroLengthND $eleTag $iNode $jNode $matTag

element zeroLengthND 28 12 122 3;

puts "**"

pattern Plain 1 Linear {
load 10 0.0 -$Weight1 0.0
load 11 0.0 -$Weight1 0.0
load 12 0.0 -$Weight2 0.0

}
puts "*"
eigen 3
puts "$$$$$"

set Tol 1.0e-8;
constraints Plain;
numberer RCM;
system SparseGeneral;
test NormDispIncr $Tol 10;
algorithm Newton;
integrator LoadControl 0.1; #first load increment (pseudo-time step) in the next invocation of the analysis command.
analysis Static;
analyze 10;
loadConst -time 0.0;
...
you before suggested use uniaxialMaterial but i didnt understand when i put stiffness ( K)instead $E.what put instead $Fy
thanks for your help.