Problem using nonlinearBeamColumn element

Strep · Post by **Strep** » Thu Aug 06, 2009 1:17 am

Dear Silvia

I'm trying to model an RC wall using fiber section and nonlinearBeamColumn element. When i try to run my script opensees shuts down when it has to define the elements (without displaying any error)!!!! it just shut down. When i use elastic beamcolumn element it's all ok. I cannot find were is the problem. This is my script:

# Basic Definitions
wipe
set dataDir Data
model BasicBuilder -ndm 2 -ndf 3

file mkdir $dataDir/;

# define UNITS ----------------------------------------------------------------------------
set m 1.; # define basic units -- output units
set kN 1.; # define basic units -- output units
set sec 1.; # define basic units -- output units
set LunitTXT "meters"; # define basic-unit text for output
set FunitTXT "kNewtons"; # define basic-unit text for output
set TunitTXT "sec"; # define basic-unit text for output
set kPa [expr $kN/pow($m,2)];
set Pa [expr $kPa/1000];
set MPa [expr $kPa*1000];
set GPa [expr $MPa*1000];
set N [expr $kN/1000];
set g [expr 10*$m/pow($sec,2)]
set PI [expr 2*asin(1.0)]; # define constants
set Ubig 1.e10; # a really large number
set Usmall [expr 1/$Ubig]; # a really small number

# nodal coordinates:
node 1 0 0 0; # node#, X, Y
node 2 0 0.915 0;
node 3 0 1.83 0
node 4 0 2.745 0
node 5 0 3.66 0

puts "nodes defined"

# Single point constraints -- Boundary Conditions
fix 1 1 1 1; # node DX DY RZ

puts "supports defined"

# we need to set up parameters that are particular to the model.
set IDctrlNode 5; # node where displacement is read for displacement control
set IDctrlDOF 1; # degree of freedom of displacement read for displacement control

# MATERIAL parameters -------------------------------------------------------------------
set IDconcU 1; # material ID tag -- unconfined cover concrete
set IDconcC 2; # material ID tag -- confined concrete
set IDreinf_3 3; # material ID tag -- reinforcement
set IDreinf_2 4; # material ID tag -- reinforcement
set IDconcV 5;

# unconfined concrete
set fcU [expr -42.8*$MPa];
set ecU -0.0021;
set EcU [expr 31.03*$GPa];
set ftU [expr 2.03*$MPa];
set etU 0.00008;
set xpU [expr 1*$Ubig];
set xnU 1.05;
set rU 7;

# confined concrete
set fcC [expr -47.6*$MPa];
set ecC -0.0033;
set EcC [expr 31.03*$GPa];
set ftC [expr 2.03*$MPa];
set etC 0.00008;
set xpC [expr 1*$Ubig];
set xnC 1.12;
set rC 1.9;

# ----------- Steel #3

set Fy_3 [expr 395*$MPa]; # STEEL yield stress
set Es_3 [expr 200*$GPa]; # modulus of steel
set b_3 0.0185; # strain-hardening ratio
set R0_3 20; # control the transition from elastic to plastic branches
set cR1_3 0.925; # control the transition from elastic to plastic branches
set cR2_3 0.15; # control the transition from elastic to plastic branches
set a1_3 18.5;
set a2_3 0.0015

# ----------- Steel #2

set Fy_2 [expr 336*$MPa]; # STEEL yield stress
set Es_2 [expr 200*$GPa]; # modulus of steel
set b_2 0.035; # strain-hardening ratio
set R0_2 20; # control the transition from elastic to plastic branches
set cR1_2 0.925; # control the transition from elastic to plastic branches
set cR2_2 0.15; # control the transition from elastic to plastic branches
set a1_2 18.5;
set a2_2 0.0015

#---------
set G [expr 1*$Ubig];

puts "values defined"

uniaxialMaterial Concrete07 $IDconcU $fcU $ecU $EcU $ftU $etU $xpU $xnU $rU
uniaxialMaterial Concrete07 $IDconcC $fcC $ecC $EcC $ftC $etC $xpC $xnC $rC
uniaxialMaterial Steel02 $IDreinf_3 $Fy_3 $Es_3 $b_3 $R0_3 $cR1_3 $cR2_3 $a1_3 $a2_3; # build reinforcement material
uniaxialMaterial Steel02 $IDreinf_2 $Fy_2 $Es_2 $b_2 $R0_2 $cR1_2 $cR2_2 $a1_2 $a2_2;
uniaxialMaterial Elastic $IDconcV $G

puts "materials defined"

# FIBER SECTION properties -----

section Fiber 100 {
patch quad $IDconcU 1219 19 -0.6095 0.032 0.6095 0.032 0.6095 0.051 -0.6095 0.051
patch quad $IDconcU 1219 19 -0.6095 -0.051 0.6095 -0.051 0.6095 -0.032 -0.6095 -0.032
patch quad $IDconcU 19 64 -0.6095 -0.032 -0.5905 -0.032 -0.5905 0.032 -0.6095 0.032
patch quad $IDconcU 19 64 0.5905 -0.032 0.6095 -0.032 0.6095 0.032 0.5905 0.032
patch quad $IDconcU 875 64 -0.4375 -0.032 0.4375 -0.032 0.4375 0.032 -0.4375 0.032
patch quad $IDconcC 153 64 -0.5905 -0.032 -0.4375 -0.032 -0.4375 0.032 -0.5905 0.032
patch quad $IDconcC 153 64 0.4375 -0.032 0.5905 -0.032 0.5905 0.032 0.4375 0.032
layer straight $IDreinf_3 4 0.0000713 -0.5905 -0.032 -0.4375 -0.032
layer straight $IDreinf_3 4 0.0000713 -0.5905 0.032 -0.4375 0.032
layer straight $IDreinf_3 4 0.0000713 0.5905 -0.032 0.4375 -0.032
layer straight $IDreinf_3 4 0.0000713 0.5905 0.032 0.4375 0.032
layer straight $IDreinf_2 4 0.000032 -0.2845 -0.032 0.2845 -0.032
layer straight $IDreinf_2 4 0.000032 -0.2845 0.032 0.2845 0.032

};

puts "fiber section defined"

section Aggregator 200 $IDconcV Vz -section 100

puts "agregatotion done"

geomTransf Linear 1
puts "tansfdef"

element nonlinearBeamColumn 1 1 2 5 200 1
element nonlinearBeamColumn 2 2 3 2 200 1
element nonlinearBeamColumn 3 3 4 2 200 1
element nonlinearBeamColumn 4 4 5 2 200 1

puts "element defined"

# Define RECORDERS -------------------------------------------------------------
recorder Node -file $dataDir/DFree.out -time -node 5 -dof 1 2 3 disp; # displacements of free nodes
recorder Node -file $dataDir/DBase.out -time -node 1 -dof 1 2 3 disp; # displacements of support nodes
recorder Node -file $dataDir/RBase.out -time -node 1 -dof 1 2 3 reaction; # support reaction
recorder Drift -file $dataDir/Drift.out -time -iNode 1 -jNode 2 -dof 1 -perpDirn 2 ; # lateral drift
recorder Element -file $dataDir/Fwall.out -time -ele 1 globalForce; # element forces -- column

# define GRAVITY -------------------------------------------------------------
pattern Plain 1 Linear {
load 5 0 [expr -532*$kN] 0
}

# Gravity-analysis parameters -- load-controlled static analysis
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 $NstepGravity; # apply gravity
# ------------------------------------------------- maintain constant gravity loads and reset time to zero
loadConst -time 0.0

puts "Model Built"

Thank you very much

silvia · Post by **silvia** » Thu Aug 06, 2009 7:12 am

check whether you are referring to a material/section that does not exist.
put little puts statements here and there to see what causes the problem.

if you run it from the dos window it is better.

Strep · Post by **Strep** » Thu Aug 06, 2009 7:39 am

Dear Silvia,

Thank you for your reply. I have put puts statements. The problem occurs when it trys to define the elements. I haven't used a material or a section that is not defined. Also I run opensees from dos window. It shut down with no errors. Only a blank line after the last puts statement. I also used dispBeamColumn element, the same error too.

Thank you

silvia · Post by **silvia** » Thu Aug 06, 2009 8:30 am

which command makes it crash?
be specific which command

Strep · Post by **Strep** » Thu Aug 06, 2009 9:40 am

it crashes after geometric transformation. the command is:

element nonlinearBeamColumn 1 1 2 5 200 1

Thank you again.

silvia · Post by **silvia** » Thu Aug 06, 2009 9:44 am

try it with an elastic section first.

Strep · Post by **Strep** » Thu Aug 06, 2009 10:01 am

I have tried this and it works just fine. When I use the nonlinearBeamColumn element I have the problems. Do you think it could be something wrong with my fiber section??

silvia · Post by **silvia** » Thu Aug 06, 2009 3:31 pm

does it work with elastic section and nonlinearBC elements? if so, yes, your fiber section has a problem. do a moment-curvature on it.

Strep · Post by **Strep** » Thu Aug 06, 2009 11:34 pm

Yes it works with elastic section and i does not with nonlinearBC. I'll try the moment -curvature as you suggest and see what happens.

Thank you very much for your help. I'll let you know what is happening...

yfeng · Post by **yfeng** » Fri Aug 07, 2009 7:33 am

Hi, I think you should try the elastic section with nonlinearBC element to see if it works. If not do the Moment Curvature analysis. If MC analysis is fine. Then try other element with your section, etc displacement based element, beamwithhinge element.

[quote="Strep"]Yes it works with elastic section and i does not with nonlinearBC. I'll try the moment -curvature as you suggest and see what happens.

Thank you very much for your help. I'll let you know what is happening...[/quote]

Strep · Post by **Strep** » Fri Aug 07, 2009 9:16 am

yfeng
thank you very much for your help.

I have manage to run the analysis. I had an extra blank line before the closing parenthensis of command section Fiber. When i delete this line i had no problems.

Silvia thank you very much for your help.