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No need for section aggregator if you just used zerolength element to assign the shear springs

You can use both. This might help you.

http://opensees.berkeley.edu/wiki/image ... Manual.pdf

You can use this document for that

http://opensees.berkeley.edu/wiki/index ... CE2004.pdf

Hi. I think I found the reference for this hysteretic material. Check "Modeling of cyclic shear behavior in RC members" by Angelo D'Ambrisi and Filip Filippou (1999). I think this is where this uniaxialmaterial was taken

cchisari wrote:
> Dear all,
>
> I would like to understand (and report in a paper) the exact formulation of
> the degradation rules for the Hysteretic material.
>
> Unfortunately, no academic reference is provided in the manual (expect for
> the qualitative aspects shown in
> http://opensees.berkeley.edu/OpenSees/m ... l/4052.htm) and I am
> not able to formulate these rules reading from the source code.
>
> Please can anyone help me with any reference?
>
> Thank you and best regards,
>
> cchisari

ismailqeshta wrote:
> I think the load factor and number of steps need to be corrected. The first
> step to identify the problem is to make sure that their multiplication is
> always equal to 1. This can, at least, ensure that you obtain the targeted
> total applied load.


Thanks for your reply! Apparently the error was on my code. Thank you!

Patrick

Hi,

I am trying to model the on shown in the photo link below:

https://drive.google.com/open?id=0BzIal ... U5wM3JZcXc

I am trying to model it by using a stdBrick element for the prismatic column (8 nodes defined - disregarding the vertical links) connected by 8 diagonal truss elements (I just used truss element to defined these materials but it should be axial springs with user defined degrading bilinear hysteretic rule). There will be an axial load applied on the column. However, it seems that the analysis is not converging. What should I do?

I also tried twoNodeLink but still it is not functioning.


wipe; # clear memory of all past model definitions

set dataDir ArakawaOA2_Palacio; # set up name of data directory
file mkdir $dataDir; # create data directory

model BasicBuilder -ndm 3 -ndf 6; # Define the model builder, ndm=#dimension, ndf=#dofs

# define GEOMETRY -------------------------------------------------------------
set LCol 225.0; # column length in mm
set Weight 190000.0; # superstructure weight
# define section geometry
set HCol 180.0; # Column Depth in mm
set BCol 180.0; # Column Width in mm

# nodal coordinates:
#Brickelement
node 1 [expr $BCol/2] $LCol [expr $HCol/2]; # node X, Y
node 4 [expr $BCol/2] $LCol [expr -$HCol/2];
node 3 [expr -$BCol/2] $LCol [expr -$HCol/2];
node 2 [expr -$BCol/2] $LCol [expr $HCol/2];
node 5 [expr $BCol/2] $Lpi [expr $HCol/2]; # node X, Y
node 6 [expr $BCol/2] $Lpi [expr -$HCol/2];
node 7 [expr -$BCol/2] $Lpi [expr -$HCol/2];
node 8 [expr -$BCol/2] $Lpi [expr $HCol/2];

#Support
node 9 [expr $BCol/2] 0.0 [expr $HCol/2]; # node X, Y
node 10 [expr $BCol/2] 0.0 [expr -$HCol/2];
node 11 [expr -$BCol/2] 0.0 [expr -$HCol/2];
node 12 [expr -$BCol/2] 0.0 [expr $HCol/2];

# Single point constraints -- Boundary Conditions
fix 9 1 1 1 0 0 0; # node DX DY RZ
fix 10 1 1 1 0 0 0; # node DX DY RZ
fix 11 1 1 1 0 0 0; # node DX DY RZ
fix 12 1 1 1 0 0 0; # node DX DY RZ


#Defining primatic column
set brickmaterial 20
set brickelement 21
nDMaterial ElasticIsotropic $brickmaterial $Ec 0.15
element stdBrick $brickelement 5 6 7 8 1 2 3 4 $brickmaterial

#Defining spring configuration
element truss 30 12 5 1.0 $diagonalspring
element truss 31 9 8 1.0 $diagonalspring
element truss 32 9 6 1.0 $diagonalspring
element truss 33 10 5 1.0 $diagonalspring
element truss 34 10 7 1.0 $diagonalspring
element truss 35 11 6 1.0 $diagonalspring
element truss 36 12 7 1.0 $diagonalspring
element truss 37 11 8 1.0 $diagonalspring

#element twoNodeLink 30 12 5 -mat $diagonalspring -dir 1;
#element twoNodeLink 31 9 8 -mat $diagonalspring -dir 1;
#element twoNodeLink 32 9 6 -mat $diagonalspring -dir 1;
#element twoNodeLink 33 5 10 -mat $diagonalspring -dir 1;
#element twoNodeLink 34 10 7 -mat $diagonalspring -dir 1;
#element twoNodeLink 35 11 6 -mat $diagonalspring -dir 1;
#element twoNodeLink 36 12 7 -mat $diagonalspring -dir 1;
#element twoNodeLink 37 11 8 -mat $diagonalspring -dir 1;

# define GRAVITY -------------------------------------------------------------
pattern Plain 1 Linear {
load 1 0 [expr -$PCol/4.0] 0 0 0 0
load 2 0 [expr -$PCol/4.0] 0 0 0 0
load 3 0 [expr -$PCol/4.0] 0 0 0 0
load 4 0 [expr -$PCol/4.0] 0 0 0 0
}

# Gravity-analysis parameters -- load-controlled static analysis
set Tol 1.0e-6; # convergence tolerance for test
constraints Transformation; # how it handles boundary conditions
numberer RCM; # 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

# Do analysis for axial load
set ok [analyze $NstepGravity]; # 0: if successful, <0 if NOT successful

if { $ok<0 } {
puts "Unsuccessful convergence!"
} else {
puts "Axial load analysis converged successfully!"
puts " ";
}

# ------------------------------------------------- maintain constant gravity loads and reset time to zero
loadConst -time 0.0


Hoping for someone to help me with this issue. Thank you very much.

Patrick

selimgunay wrote:
> Please indicate your contact email. I will send it to interested people
> soon.

Hi,

I am interested on the shear-flexure interaction on zero length element source code. My email address is pcgarcia@up.edu.ph. I am also working on the same topic.

Thanks,

Patrick

I also have the same question. But I think the best way is to just add a new hysteretic material with specific degradation rule

Hi! Can I also get a copy of your sourcecode? Thanks!

aylsworthgarcia@gmail.com

Hi,

Need help on my new uniaxialmaterial. I already compiled and obtained a dll file. However, when I loaded it in Opensees, it says:

WARNING: numeric analysis returns 1 -- Umfpackgenlinsolver::solve
WARNING NewtonRaphson::solveCurrentStep() - the LinearSysofEqn failed in solve()
StaticAnalysis::analyze() - the Algorithm failed at iteration: 0 with domain at load factor 0.01
Domain::update - domain failed in update
Opensees > analyze failed, returned: -3 error flag -3


The code I used was the Mattest.tcl which is included in the command language manual. I am trying to model a material with degrading bilinear hysteretic rule.

Thanks for your help!

Patrick



# matTest.tcl: SDOF truss to test uniaxial material models
# Units: kip, in
# MHS, Sept 1999
# email: mhscott@ce.berkeley.edu

wipe
model BasicBuilder -ndm 1 -ndf 1
# Define nodes
node 1 0.0
node 2 1.0
# Fix node 1
fix 1 1

# Define uniaxialMaterial
#uniaxialMaterial DegradingBilinear mattag Ky Dy Fy Ku B0 dmaxT dmaxC
uniaxialMaterial DegradingBilinear 1 [expr 3.50/0.002] 0.006 3.50 [expr (5.0-3.5)/(0.01-0.006)] 0.4 0.10 -0.10;

#uniaxialMaterial ElasticPPcpp 1 3000.0 0.03;

# Define truss element with unit area
# tag ndI ndJ A matTag
element truss 3 1 2 1.0 1
set dt 0.010 ;# Increment between data points
set filename pattern1.txt ;# Filename containing data points
set factor 0.006 ;# Factor applied to data values
# Read displacement pattern from file
# Note, any pattern type can be used here: Linear, Path, Sine, etc.
pattern Plain 1 "Series -dt $dt -filePath $filename -factor $factor" {
# Set reference displacement value
# node dof value
sp 2 1 1.0
}

# Impose monotonic displacements
#pattern Plain 2 "Linear -factor $factor" {
# sp 2 1 1.0
#}
# Record nodal displacements (same as strains since truss length is 1.0)
#recorder Node -file truss.out disp -load -node 2 -dof 1
recorder Node -file truss.txt -time -node 2 -dof 1 disp;
# Record truss force (same as stress since truss area is 1.0)
recorder Element -file force.txt -time -ele 3 localForce
system UmfPack
constraints Penalty 1.0e12 1.0e12
# Set increment in load factor used for integration
# Does not have to be the same as dt used to read in displacement pattern
set dl $dt
integrator LoadControl $dl 1 $dl $dl
test NormDispIncr 1.0e-6 10
algorithm Newton
numberer RCM
analysis Static
analyze 10000

Hysteretic rule on loading, unloading, and reloading such as Takeda, Fukada, Clough, etc. in complement to uniaxialMaterial Hysteretic

Thanks for the help Sir! I was able to run the model now though the result is somehow different from the cyclic data that I have.

Yes SIr. The code I used is

uniaxialMaterial Hysteretic $ColMatTagFlex $Mcr $Mdcr $My $Mdy $Mu $Mdu [expr -$Mcr] [expr -$Mdcr] [expr -$My] [expr -$Mdy] [expr -$Mu] [expr -$Mdu] $pinchX $pinchY 0 0 0 4 6;

When I remove the 4 6 in the last part of the code, the programs terminates automatically when I run the whole code. Please check image link below for reference
https://drive.google.com/open?id=0BzIal ... XczWENHV1U

For the rotation spring, is it possible to have a user-define limit curve for the uniaxialMaterial Hysteretic as when I try to run the code, it says to define limitcurve after $damage2 and DOF right after it.

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

Thank you Sir!

selimgunay wrote:
> Please use the axial material directly in the zerolength element in
> direction 2 and define your beam column element as elasticBeamColumn.


Thank you Sir! I was able to model the springs.

By the way, I have another question, is the shear spring incorporated in zerolength element compatible with beamwithhinge element with fiber section of concrete and steel? Does the shear spring in effect when I use the code below?
Thank you very much Sir for your help!

node 1 0 0;
node 2 0 0;
node 3 0 $LCol;

uniaxialMaterial LimitState $shearTag $Vcr $dcr $Vy $dy $Vu $du [expr -$Vcr] [expr -$dcr] [expr -$Vy] [expr -$dy] [expr -$Vu] [expr -$du] $pinchX $pinchY $damage1 $damage2 $beta $shearCurveTag 2 0
section fiberSec $ColSecTag{
...(concrete fibers and steel fibers defined here)
}

element beamWithHinges 1 2 3 $ColSecTag $Lpi $ColSecTag 0 $Ec $ACol $IzCol $ColTransfTag;
element zeroLength 2 1 2 -mat $shearTag -dir 2;