hystertic material

[asra]

dear silvia
when i modelling asection or element with hystetic material with 3points(in tension and in compression)when the tangent of lines higher than previous line the element act as bi-linear instead of 3line.what can i do to solve this problem?

[silvia]

i just tested mine and it works fine.
please check your model in detail and if it still doesnt' work, please send me your material properties and your strain history.

[asra]

the model is too long so i send you a commands that related this topic;

Code: Select all

#============Define parameters
set fy 2.4e4 ;        # Yield stress  !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
set E 2.1e7   

; # Young's modulus
set G 8.08e6; # Shear modulus
set bx 18.0; #diaphragm length
set by 15.0; #Diaphragm width
set h 3.3; #Model height
set PGA 0.5; #Maximum Eq acceleration per g
set pga 0.2557; #Maximum Eq acceleration of file per g
set m 18.96; #mass=weight/9.81
set em 0.0; #mass eccentricity
set landa 0.2;


#for brace
set A 7.57E-4; #area of brace

set L 6 ; #length of brace
set Ib 1.21E-6; #moment of inertia of brace
set SL 6 ; #slip load of FD
set dl [expr ($SL*$L)/($A*$E)]; #deformation of brace when slip
set hole .02; #hole of FD
set er 0.0; #error of this method
set ft [expr ($A * $fy)]; #point 3 of hystertic in tension (force)
set dtf [expr ($ft -$SL) * $L/($E*$A)];
set dtot [expr ($dl+$hole+$dtf)] ; #total displacement in tension
set fp [expr (3.14*3.14*$E*$Ib)/($L*$L)]; #point 3 of hystertic in compression(force)
set dnf [expr ($fp -$SL) * $L/($E*$A)];
set dn [expr ($dl+$hole+$dnf)]; #total displacement in compression
#hystertic material
#uniaxialMaterial Hysteretic $matTag $s1p $e1p $s2p $e2p $s3p $e3p $s1n $e1n $s2n $e2n $s3n $e3n $pinchX $pinchY $damage1 $damage2
uniaxialMaterial Hysteretic 34 $SL $dl [expr ($SL+$er)] [expr ($dl+$hole)] $ft $dtot -$SL -$dl [expr -($SL+$er)] [expr -($dl+$hole)] [expr (-$fp)] [expr (-$dn)] 0 0 0 0;


#-------brace
#section Uniaxial $secTag $matTag $string

section Uniaxial 19 34 P
#element truss $eleTag $iNode $jNode $secTag
element truss 133 1 105 19


[/code]


i want to send you the hystertic curve of this model how can isend you?[/img]

[silvia]

please put into your code:

puts "uniaxialMaterial Hysteretic 34 $SL $dl [expr ($SL+$er)] [expr ($dl+$hole)] $ft $dtot -$SL -$dl [expr -($SL+$er)] [expr -($dl+$hole)] [expr (-$fp)] [expr (-$dn)] 0 0 0 0"

and give me what you get.

[asra]

im putting this command the data showing that response of three line but when i get the hystertic curve of this material it showing two line.
i send you the command that i use for hystetic curve:

Code: Select all

#uniaxialMaterial Hysteretic $matTag    $s1p     $e1p          $s2p                    $e2p            $s3p  $e3p       $s1n      $e1n        $s2n                      $e2n                $s3n              $e3n            $pinchX $pinchY $damage1 $damage2
 uniaxialMaterial Hysteretic    34      $SL      $dl     [expr ($SL+$er)]       [expr ($dl+$hole)]     $ft   $dtot      -$SL     -$dl     [expr -($SL+$er)]       [expr -($dl+$hole)]    [expr (-$fp)]   [expr (-$dn)]           0       0         0        0;

#-------brace
#section Uniaxial $secTag    $matTag $string

section Uniaxial     19         34      P 
#element truss $eleTag   $iNode $jNode $secTag
element truss  133         1     105    19

recorder Element -file $dataDir/eled.txt  -time -ele 133    deformation
recorder Element -file $dataDir/elef.txt  -time -ele 133    force

i want to see the hystetic curve of the element 133 .is the command that i use for record true?if false help me for solving this problem?

if this command true then maybe the hystertic material with three line with when slope of each line increase in structure model in dynamic analysis cant act.i have the hystertic curve that i got from this program if you want isend you.
thanks alot

[silvia]

please give me the specific numbers you are inputting that's why i asked you to send me what the command looks like.

[asra]

ok i done the puts command before hystertic material and i got this number:
6 0.00226 6 0.02226 18.168 0.0268
-6 -0.00226 -6 -0.02226 -6.95 -0.02262

[silvia]

it should look something like
uniaxialMaterial Hysteretic 34 2.2.... and whatever values are input.

[asra]

NO PINCHING AND NO DAMAGE(0 0 0 0)

[asra]

yes,but in analysis i got the bi-linear curve .i sent you the command that i use for got hystertic curve.they are true?
what can i do?in history analysis the third line disable.
i m guessing for short different between my deformation number the third line doesnt exist.

[silvia]

the third line is there.
if you give me your input command without variables i can check it for you!

[asra]

uniaxialMaterial Hysteretic 34 6 0.00226 6 0.02226 18.168 0.0268 -6 -0.00226 -6

-0.02226 -6.95 -0.02262 0 0 0 0,

[asra]

if you want i will send you full program .
please say me is this command for record the deformation and force of element true or maybe the problem from this command.

Code: Select all

recorder Element -file $dataDir/eled.txt  -time -ele 133    deformation
recorder Element -file $dataDir/elef.txt  -time -ele 133    force

the element im using truss .

[silvia]

try to make the second tangent NOT zero!

[asra]

thanks alot.i change the slope of second line in variable slopes and the hystertic curve of all of them bi-linear.either the total deformation of hystertic curve is more than input number .is hystertic material act in dynamic analysis true?i think this material acting wrong?