analyze failed

[firubila]

Hi, i'm trying to model a bridge frame which consists in column (two node link), bearing (zero length element), steel stoper (zero length element), beams (two node link) and rigid element between them.

When i run it, opensees says "analyze failed, returned: -3 error flag -3"

What is the problem?

Thanks.

My code is this:

# Modelo NCEE 2014 - Conferencia Alaska
# =====================================
# FRM - Septiembre - 2013
# =====================================
# Unidades: Ton, cm, seg.
# =====================================
wipe all;
model BasicBuilder -ndm 2 -ndf 3;
set dataDir Results_NCEE;
file mkdir $dataDir

# Geometria
# =========

# Parametros
set b 50; # medida standar (cm)
set Lv 100; # alto vigas (cm)
set Lc 300; # alto columnas (cm)

# Coordenadas
node 1 [expr 2*$b] 0.0;
node 2 0.0 $Lc;
node 3 0.0 $Lc;
node 4 $b $Lc;
node 5 $b $Lc;
node 6 [expr 2*$b] $Lc;
node 7 [expr 3*$b] $Lc;
node 8 [expr 3*$b] $Lc;
node 9 [expr 4*$b] $Lc;
node 10 [expr 4*$b] $Lc;
node 11 0.0 [expr $Lc + $Lv];
node 12 $b [expr $Lc + $Lv];
node 13 [expr 3*$b] [expr $Lc + $Lv];
node 14 [expr 4*$b] [expr $Lc + $Lv];

# CB
fix 1 1 1 1;


# Masas
# =====
set Msup 5.0; # Masa superestructura (Ton)
set Msub 3.0; # Masa subestructura (Ton)
set msup [expr $Msup/4.0];
set msub [expr $Msub/5.0];

mass 2 $msub 1e-9 0.;
mass 4 $msub 1e-9 0.;
mass 6 $msub 1e-9 0.;
mass 7 $msub 1e-9 0.;
mass 9 $msub 1e-9 0.;
mass 11 $msup 1e-9 0.;
mass 12 $msup 1e-9 0.;
mass 13 $msup 1e-9 0.;
mass 14 $msup 1e-9 0.;


set TransfTag 1;
geomTransf Linear $TransfTag;

# Elementos
# ==========
# Columnas
set Kc 28.65; # (Ton/cm)

# Vigas
set Kv [expr $Kc/10]; # (Ton/cm)

# Bearings
set Eb 0.612; # (Ton/cm)
set epsyP 10; # (cm)

# Stoppers
set s1p 3.06; # (Ton) = 30 kN
set s2p 8.16; # (Ton) = 80 kN
set s3p 0.1;
set e1p 0.15; # cm
set e2p 3.4;
set e3p 8.0;
set s1n -3.06;
set s2n -8.16;
set s3n -0.1;
set e1n -0.15;
set e2n -3.4;
set e3n -8.0;
set pinchX 1.0;
set pinchY 0.0;
set damage1 0.0;
set damage2 0.0;

# Elementos rígidos
set Ab [expr 30.*30.];
set fc 250.;
set Er [expr 151000000.*sqrt($fc)];
set Ib 10e+12;

set matTagCol 1;
set matTagBeam 2;
set matTagBearing 3;
set matTagStopper 4;

# Columna
# =======
uniaxialMaterial Elastic $matTagCol $Kc
element twoNodeLink 1 1 6 -mat $matTagCol -dir 2

# Vigas
# ======
uniaxialMaterial Elastic $matTagBeam $Kv
element twoNodeLink 2 3 11 -mat $matTagBeam -dir 2
element twoNodeLink 3 5 12 -mat $matTagBeam -dir 2
element twoNodeLink 4 8 13 -mat $matTagBeam -dir 2
element twoNodeLink 5 10 14 -mat $matTagBeam -dir 2

# Apoyos elastoméricos
# ====================
uniaxialMaterial ElasticPP $matTagBearing $Eb $epsyP
element zeroLength 6 2 3 -mat $matTagBearing -dir 2
element zeroLength 8 4 5 -mat $matTagBearing -dir 2
element zeroLength 10 7 8 -mat $matTagBearing -dir 2
element zeroLength 12 9 10 -mat $matTagBearing -dir 2

# Stoppers
# ========
uniaxialMaterial Hysteretic $matTagStopper $s1p $e1p $s2p $e2p $s3p $e3p $s1n $e1n $s2n $e2n $s3n $e3n $pinchX $pinchY $damage1 $damage2
element zeroLength 7 2 3 -mat $matTagStopper -dir 2
element zeroLength 9 4 5 -mat $matTagStopper -dir 2
element zeroLength 11 7 8 -mat $matTagStopper -dir 2
element zeroLength 13 9 10 -mat $matTagStopper -dir 2

# Elementos rigidos
# =================
element elasticBeamColumn 14 2 4 $Ab $Er $Ib $TransfTag;
element elasticBeamColumn 15 4 6 $Ab $Er $Ib $TransfTag;
element elasticBeamColumn 16 6 7 $Ab $Er $Ib $TransfTag;
element elasticBeamColumn 17 7 9 $Ab $Er $Ib $TransfTag;
element elasticBeamColumn 18 11 12 $Ab $Er $Ib $TransfTag;
element elasticBeamColumn 19 13 14 $Ab $Er $Ib $TransfTag;


# RECORDERS
# =========

# Desplazamientos en X
recorder Node -file $dataDir/DFreeNode2.out -time -node 2 -dof 1 2 3 disp;
recorder Node -file $dataDir/DFreeNode3.out -time -node 3 -dof 1 2 3 disp;
recorder Node -file $dataDir/DFreeNode11.out -time -node 11 -dof 1 2 3 disp;
recorder Node -file $dataDir/DFreeNode9.out -time -node 9 -dof 1 2 3 disp;
recorder Node -file $dataDir/DFreeNode10.out -time -node 10 -dof 1 2 3 disp;
recorder Node -file $dataDir/DFreeNode14.out -time -node 14 -dof 1 2 3 disp;


# Reacción en el apoyo izquierdo
recorder Node -file $dataDir/RBase.out -time -node 1 -dof 1 2 3 reaction;

# Pushover
# =========
pattern Plain 1 Linear {
load 11 100.0 0.0 0.0
}

# PARAMETROS DE ANALISIS
# ======================
set Tol 1.0e-8; # convergence tolerance for test
constraints Plain; # how it handles boundary conditions
numberer Plain; # renumber dof's to minimize band-width (optimization), if you want to
system BandGeneral; # how to store and solve the system of equations in the analysis
test NormDispIncr $Tol 6 ; # determine if convergence has been achieved at the end of an iteration step
algorithm Newton; # use Newton's solution algorithm: updates tangent stiffness at every iteration
set NstepGravity 10; # apply gravity in 10 steps
set DGravity [expr 1./$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 100;



FRM- MSc. Student - PUC, Chile.

[mhscott]

Check your model for rigid body motion due to improper support restraints. Check various other posts on the message board about what to do when an analysis fails. There are several posts like yours with answers that will be applicable.

[vesna]

Can you post the full message that you get from OpenSees?

[firubila]

WARNING BandGenLinLapackSolver: : solve() - LAPACK routine returned 6
WARNING NewtonRaphson: : solveCurrentStep() - the LinearSysOfEqn failed in solve()
StaticAnalysis: : analyze() - the Algorithm failed at iteration: 0 with domain at load factor 0.1

analyze failed, returned: -3 error flag -3

[mhscott]

When the solver fails, it's most likely your support conditions are not preventing rigid body motion or there is an error in your element connectivity, e.g., there is a node that is not connected to any elements.