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Hi dear McKenna,

I'm running transient analysis on a forceBeamColumn with different mass and I have the same displacement history. With a different fundamental period, it should has a different history ?

Thanks a lot for your help.

Hi,

I'm using Pinching4 to introduce shear deformation into forceBeamColumn for a pushover analysis but the force-displacement curves is the exact curve of the Pinching4. It seem like the flexural and axial stiffness haven't effect on the response of the reinforced wall. I'm using force and angular deformation to define Pinching4.

Thank a lot to help me,

I downloaded the last version 2.4.5 and the command is unavailable. There is something I'm doing wrong.

When the uniaxialmaterial Steel4 will be available in OpenSees ? I would like to try with my model.

Thank for your hint. I have a question that might help me. I have brace in the macro-element with end release on each corner. I am using beam-column for the beam then I'm doing :

model BasicBuilder -ndm 2 -ndf 3;

then, do I have to restraint the rotation for each node of the truss elements who are connected with the node of beam with equalDOF ?

Hi everyone,

I'm trying to reproduce that macro-element :

O’Donnell, A., Kurama, Y., and Taflanidis, A. “An analytical modeling framework for seismic risk assessment of unreinforced masonry structures.”

but I have an instability in my model, but I don't know where (look at the end for the error messages). Here is my code :

wipe;
file mkdir Data;
model BasicBuilder -ndm 2 -ndf 3;

# Geometry
set Hwall [expr 2641.*$mm];
set Lwall [expr 3000.*$mm];
set ewall [expr 190.*$mm];
set hblock [expr 190.*$mm];
set egrout [expr 10.*$mm];
set efiber [expr $hblock+2.*$egrout]
set gamma [expr atan(($Lwall-2.*$efiber)/($Hwall-2.*$efiber))]
set Pdl [expr 855.*$kN];
set Awall [expr $Lwall*$ewall];
set Izwall [expr 1./12.*$ewall*pow($Lwall,3)];

# Material Tag
set ZLTSmatTag 1;
set DTEmatTag 2;
set FBCEmatTag 3;
set FBCEmasTag 11;
set ZLRSmatTag 4;

# ZERO-LENGTH TRANSLATIONAL SPRINGS ---------------------------------------------------------------
set Ksi [expr 1000.*$kip_in]
set Ksc [expr 0.09*$Ksi]

set c 0.;
set mu 0.65;
set Fsu [expr ($c+$mu*$Pdl/$Awall)*$Awall]
set Fsc [expr 0.5*$Fsu]

set s1p $Fsc
set e1p [expr $Fsc/$Ksi]
set s2p $Fsu
set e2p [expr $e1p+($Fsu-$Fsc)/$Ksc]
set s3p [expr 1.005*$Fsu]
set e3p [expr 10.*$e2p]

set s1n [expr -$s1p]
set e1n [expr -$e1p]
set s2n [expr -$s2p]
set e2n [expr -$e2p]
set s3n [expr -$s3p]
set e3n [expr -$e3p]

set pinchX 1.0;
set pinchY 1.0;
set damage1 0.0;
set damage2 0.0;
set beta 0.0;

uniaxialMaterial Hysteretic $ZLTSmatTag $s1p $e1p $s2p $e2p $s3p $e3p $s1n $e1n $s2n $e2n $s3n $e3n $pinchX $pinchY $damage1 $damage2 $beta

# DIAGONAL TRUSS ELEMENTS -------------------------------------------------------------------------
set G [expr 5700.*$MPa]
set Kdi [expr $G*$Awall/(2*pow(sin($gamma),2)*$Hwall)]
set Kdc [expr 0.5*$Kdi]

set b [expr $Hwall/$Lwall]
set ft [expr 1.*$MPa]
set tu [expr $ft/$b*pow($Pdl/($Awall*$ft)+1,0.5)]
set Vu [expr $tu*$Awall]

set Fdc [expr $Vu/(2*sin($gamma))]
set ftd [expr 2.3*$MPa]
set tu2 [expr $ftd/$b*pow($Pdl/($Awall*$ftd)+1,0.5)]
set Vu2 [expr $tu2*$Awall]
set Fdu [expr $Vu2/(2*sin($gamma))]

set s1p $Fdc
set e1p [expr $Fdc/$Kdi]
set s2p $Fdu
set e2p [expr $e1p+($Fdu-$Fdc)/$Kdc]
set s3p [expr 1.005*$Fdu]
set e3p [expr 10.*$e2p]

set s1n [expr -$s1p]
set e1n [expr -$e1p]
set s2n [expr -$s2p]
set e2n [expr -$e2p]
set s3n [expr -$s3p]
set e3n [expr -$e3p]

set pinchX 1.0;
set pinchY 1.0;
set damage1 0.0;
set damage2 0.0;
set beta 0.0;

uniaxialMaterial Hysteretic $DTEmatTag $s1p $e1p $s2p $e2p $s3p $e3p $s1n $e1n $s2n $e2n $s3n $e3n $pinchX $pinchY $damage1 $damage2 $beta

# FIBER BEAM-COLUMN ELEMENTS ----------------------------------------------------------------------
set fc1U [expr -17.5*$MPa]; # UNCONFINED concrete (todeschini parabolic model), maximum stress
set Ec [expr -15000.*$MPa]; # Concrete Elastic Modulus (the term in sqr root needs to be in psi
set eps1U -0.003; # strain at maximum strength of unconfined concrete
set fc2U [expr 0.2*$fc1U*$MPa]; # ultimate stress
set eps2U -0.0105; # strain at ultimate stress

uniaxialMaterial Concrete01 $FBCEmasTag $fc1U $eps1U $fc2U $eps2U;

set coverY [expr $Lwall/2.0]; # The distance from the section z-axis to the edge of the cover concrete -- outer edge of cover concrete
set coverZ [expr $ewall/2.0]; # The distance from the section y-axis to the edge of the cover concrete -- outer edge of cover concrete
set nfY 300;
set nfZ 1;
section Fiber $FBCEmatTag {;
patch rect $FBCEmasTag $nfY $nfZ -$coverY -$coverZ $coverY $coverZ;
}

# ZERO-LENGTH LINEAR-ELASTIC ROTATIONAL SPRINGS ---------------------------------------------------
uniaxialMaterial Elastic $ZLRSmatTag [expr 3.*$Ec*$Izwall/(0.5*$Hwall-$efiber)]

# Nodal coordinates --------------------------------------------------------------------------
# X Y
node 1 [expr -$Lwall/2+$efiber] $efiber
node 2 [expr $Lwall/2-$efiber] $efiber
node 3 [expr $Lwall/2-$efiber] [expr $Hwall-$efiber]
node 4 [expr -$Lwall/2+$efiber] [expr $Hwall-$efiber]
node 5 0 0
node 6 0 $efiber
node 7 0 [expr $Hwall-$efiber]
node 8 0 $Hwall

# Constraints ---------------------------------------------------------------------------
# node DX DY RZ
fix 5 1 1 1;
fix 1 0 0 0;
fix 2 0 0 0;
fix 3 0 0 0;
fix 4 0 0 0;
fix 6 0 0 0;
fix 7 0 0 0;
fix 8 0 0 0;


set TransfTag 1; # associate a tag to column transformation
geomTransf Linear $TransfTag;

# Element Tag --------------------------------------------------------------------------------
set ZLTSsecTag1 1
set ZLTSsecTag2 2
set DTEsecTag1 3
set DTEsecTag2 4
set FBCEsecTag1 5
set FBCEsecTag2 6
set ZLRSsecTag1 7

# RIGID LINKS -------------------------------------------------------------------------------------
equalDOF 6 1 1 2;
equalDOF 6 2 1 2;
equalDOF 7 3 1 2;
equalDOF 7 4 1 2;

# ZERO-LENGTH TRANSLATIONAL SPRINGS ---------------------------------------------------------------
element zeroLength $ZLTSsecTag2 7 8 -mat $ZLTSmatTag -dir 1

# DIAGONAL TRUSS ELEMENTS -------------------------------------------------------------------------
element twoNodeLink $DTEsecTag1 1 3 -mat $DTEmatTag -dir 1
element twoNodeLink $DTEsecTag2 2 4 -mat $DTEmatTag -dir 1

# FIBER BEAM-COLUMN ELEMENTS ----------------------------------------------------------------------
set numIntgrPts 3;
element forceBeamColumn $FBCEsecTag1 5 6 $numIntgrPts $FBCEmatTag $TransfTag
element forceBeamColumn $FBCEsecTag2 7 8 $numIntgrPts $FBCEmatTag $TransfTag

# ZERO-LENGTH LINEAR-ELASTIC ROTATIONAL SPRINGS ---------------------------------------------------
element zeroLength $ZLRSsecTag1 6 7 -mat $ZLRSmatTag -dir 6

pattern Plain 1 Linear {
load 8 0 -$Pdl 0
}

# Gravity-analysis parameters -- load-controlled static analysis
set Tol 1.0e-8; # convergence tolerance for test
constraints Lagrange; # how it handles boundary conditions
numberer Plain; # renumber dof's to minimize band-width (optimization), if you want to
system SparseGeneral ; # how to store and solve the system of equations in the analysis
test NormDispIncr $Tol 6 ; # determine if convergence has been achieved at the end of an iteration step
algorithm ModifiedNewton; # use Newton's solution algorithm: updates tangent stiffness at every iteration
set NstepGravity 10; # apply gravity in 10 steps
set DGravity [expr 1./$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

and I got as results :

WARNING SuperLU::solve(void)- Error 3 returned in factorization dgstrf()
WARNING ModifiedNewton::solveCurrentStep() -the LinearSysOfEqn failed in solve()

StaticAnalysis::analyze() - the Algorithm failed at iteration: 0 with domain at load factor -1
OpenSees analyze failed, returned: -3 error flag