IDA on bridges

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andrett7
Posts: 118
Joined: Fri Dec 04, 2009 5:23 am
Location: Politecnico di Milano

IDA on bridges

Post by andrett7 »

Dear all,
I want to perform IDA on a bridges (3D analysis). Deck is elastic while piers are modelled through beamWithHinges element. Their inelastic behaviour comes a linearization of the moment-curvature diagram, using hysteretic material. Such material is then coupled with a MinMax material when curvature reaches the ultimate value. The problem is that when moment goes to zero the shear still has values different from zero and therefore I cannot reach the collapse of the structure. Do you have any suggestion?
Below there is the part of the script which defines the nonlinear behaviour of the piers.

Thanks.
Andrea

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

set matID 1
set matLimID 2

set fid [open InviluppoMom.out r]; # Informazioni sulla sezione della colonna (Mcrack, Myield, Mmax, Mult)
set InviluppoMom [read $fid]
close $fid
set s1p [lindex $InviluppoMom 0];
set s2p [lindex $InviluppoMom 1];
set s3p [lindex $InviluppoMom 2];
set s1n -$s1p
set s2n -$s2p
set s3n -$s3p

set fid [open InviluppoCurv.out r]; # Informazioni sulla sezione della colonna (Chicrack, Chiyield, Chimax, Chiult)
set InviluppoCurv [read $fid]
close $fid
set Chiult [lindex $InviluppoCurv 3]
set e1p [lindex $InviluppoCurv 0];
set e2p [lindex $InviluppoCurv 1];
set e3p [lindex $InviluppoCurv 2];
set e1n -$e1p
set e2n -$e2p
set e3n -$e3p

set pinchX 0.6
set pinchY 0.2;
set damage1 0.0
set damage2 0.2
set beta 0.5

uniaxialMaterial Hysteretic $matID $s1p $e1p $s2p $e2p $s3p $e3p $s1n $e1n $s2n $e2n $s3n $e3n $pinchX $pinchY $damage1 $damage2 $beta
uniaxialMaterial MinMax $matLimID $matID -min -$Chiult -max $Chiult

# Assign torsional Stiffness for 3D Model
uniaxialMaterial Elastic $secTagTorsion $Ubig
# Assign axial stiffness
set fc 40; # Concrete nominal compressive strength (MPa)
set Ec [expr $MPa*5000*pow($fc,0.5)]; # Concrete Young's Modulus
set AgCol [expr 4160000*$mm2];
set EAPier [expr $Ec*$AgCol]; # EA, for axial-force-strain relationship
uniaxialMaterial Elastic $ColMatTagAxial $EAPier;

section Aggregator $ColsecTag $secTagTorsion T $ColMatTagAxial P $matLimID Mz
Scientists study the world as it is; engineers create the world that never has been.
Hwoarang
Posts: 18
Joined: Mon Jul 16, 2018 11:27 pm

Re: IDA on bridges

Post by Hwoarang »

Hello

Is there anyone who has an OpenSees example for 3D IDA analysis? Thank you if you share it.
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