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You are the best! Thanks again.

So damping is not included even for LocalForces, right?

Thanks Frank
I am guessing that by "forces" you refer to the newer 2.2.0 commands and it corresponds to "globalforces". In that case, does "localforces" work in the same way? Finally, how about the older versions (pre 2.0.0)? I am postprocessing some results derived with such a version and some of them are produced by globalforce and localforce. Is damping included there?

Thanks again.

In the following post, there has been some discussion on this issue and it seems that the answer may be element-type-dependent.

(opensees.berkeley.edu/community/viewtopic.php?t=16477)

So, if possible (Frank?) could you tell me what is included by an ElementRecorder for a force-based beam-column element? If inertia and/or damping effects are included, is there any way to remove them, short of modifying the OpenSees source code?

It seems that the -INFO command line argument has been abandoned in the newer versions of OpenSEES. Has it been replaced by another mechanism, or are there any ideas to bring it back? It was mighty useful.

Many thanks!

Does anybody know what are the columns in the output of an element Plasticrotation recorder for 3D nonlinear beam-columns?

There are 7 columns, the only obvious one being the first (time).

Cathy:

Sorry for taking so long to answer, I just saw the message! In general, in the older versions of opensees, including the -load or -time command will also place in the output the load that corresponds to the element in question.

In my case this was an axial load for the uniaxial material.

Depending on the structure and loading imposed you will get different outputs here.

oops, correction:

>> ! opensees inputfile.tcl

simply go to the directory where opensees and inputfile.tcl reside and then run opensees as a system command from Matlab:

For example, within Matlab, if your files are in c:\opensees,

>> cd c:\opensees
>> opensees inputfile.tcl

I hope this helps.

I am not sure if this is a bug or not but it seems that upgrading from Opensees 1.6.1 to 1.7.1 and above totally destroys any script that uses the Joint element.

What happens is that the script produces a straight black screen once an "analyze" command is issued and enters what seems to be an endless loop, even for the simplest of gravity loads.

Does anybody have any suggestions on this?

There are more issues when modeling fiber beams with a rigid diaphragm. The problem is that there actually exists an axial DOF for the fiber beam.

If you completely constrain this axial DOF then you get immediately large prestressing forces that can increase your strength for the fiber sections.

If you remove the axial constraint, then the beams will lose strength and crack or even become develop hinges even under gravity loads.

Thanks Nero, that is exactly what I mean. In this way you can send a script to your collegues and they will immediately receive the proper error (incorrect version of openSEES) rather than a cryptic error about a material model not being present.

It may prove useful to have a function available in the Tcl interface that would report what version of openSEES is currently running. It will probably help to ensure that any structural model is running on an up-to-date version of OpenSEES, at least as up-to-date as it needs!

This should be incredibly simple to implement.

Silvia, this is not my script, I just got if from the openSEES manual entry for the pinching4 uniaxialmaterial model. I modified it to show how it can fail in Displacement Control analysis. Note that this is an obvious overkill. I could have just use a single Displacement Control pushover in one direction to force this to fail.

Note that this is not a problem with the material model. The same thing happens even for steel01 with a negative post-yield stiffness or the hysteretic material. I have even tried using the Arclength and it still doesn't work.

Of course there is an obvious solution to the problem: Place this spring in parallel with a very stiff elastic spring and then do the pushover. Simply record the force vs displacement of the desired spring and you are done. Still, in the interest of improving OpenSEES, solving this issue at its source may prove more useful!


##################################################################################################################
# Test example for PINCHING MATERIAL #
# Written: N.Mitra #
# Description: uniaxial material with user defined envelope (softening type used here) and damage parameters #
# Date: May 04 2002 #
## Model subjected to reverse Cyclic Loading #
## File Name: RCyclicPinch.tcl #
# refer to Pinching-Type Material Model.doc for full explanation of the parameters #
##################################################################################################################
# MODIFIED BY D.VAMVATSIKOS TO MAKE IT FAIL!!!


#create the ModelBuilder object
model BasicBuilder -ndm 2 -ndf 2

# add nodes - command: node nodeId xCrd yCrd
node 1 0.0 0.0
node 2 1.0 0.0


## please keep the following procedures on the same path
source procUniaxialPinching.tcl
source procRCycDAns.tcl


##### Positive/Negative envelope Stress/Load
### stress1 stress2 stress3 stress4

set pEnvelopeStress [list 2.0 6.0 7.0 0.2]
set nEnvelopeStress [list -2.0 -6.0 -7.0 -0.2]


##### Positive/Negative envelope Strain/Deformation
### strain1 strain2 strain3 strain4
set pEnvelopeStrain [list 0.0001 0.0055 0.0188 0.0189]
set nEnvelopeStrain [list -0.0001 -0.0055 -0.0188 -0.0189]

##### Ratio of maximum deformation at which reloading begins
### Pos_env. Neg_env.
set rDisp [list 0.5 0.5]

##### Ratio of envelope force (corresponding to maximum deformation) at which reloading begins
### Pos_env. Neg_env.
set rForce [list 0.25 0.25]


##### Ratio of monotonic strength developed upon unloading
### Pos_env. Neg_env.
set uForce [list 0.05 0.05]


##### Coefficients for Unloading Stiffness degradation
### gammaK1 gammaK2 gammaK3 gammaK4 gammaKLimit
#set gammaK [list 1.0 0.2 0.3 0.2 0.9]
set gammaK [list 0.0 0.0 0.0 0.0 0.0]

##### Coefficients for Reloading Stiffness degradation

### gammaD1 gammaD2 gammaD3 gammaD4 gammaDLimit
#set gammaD [list 0.5 0.5 2.0 2.0 0.5]
set gammaD [list 0.0 0.0 0.0 0.0 0.0]


##### Coefficients for Strength degradation
### gammaF1 gammaF2 gammaF3 gammaF4 gammaFLimit
#set gammaF [list 1.0 0.0 1.0 1.0 0.9]
set gammaF [list 0.0 0.0 0.0 0.0 0.0]

set gammaE 10

# material ID
set matID 1


# damage type (option: "energy", "cycle")
#set dam "energy"
set dam "cycle"

# add the material to domain through the use of a procedure

procUniaxialPinching $matID $pEnvelopeStress $nEnvelopeStress $pEnvelopeStrain $nEnvelopeStrain $rDisp $rForce $uForce $gammaK $gammaD $gammaF $gammaE $dam


# add truss elements - command: element truss trussID node1 node2 A matID
element truss 1 1 2 1.0 1


# set the boundary conditions - command: fix nodeID xResrnt? yRestrnt?
fix 1 1 1
fix 2 0 1


pattern Plain 1 Linear {
load 2 1 0
}

# NOTE here: IF you include -load or -time, you also get the axial load output. If you do not, then
# you only get the nodal displacement!
recorder Node -file RCyclicPinchR.out -load -node 2 -dof 1 disp

# build the components for the analysis object
system ProfileSPD
constraints Plain
test NormDispIncr 1.0e-8 20
algorithm Newton
numberer RCM




## analysis type used in the procedure is Static


set peakpts [list 0.0001 0.001 0.002 0.003 0.005 0.006 0.007 0.009 0.01 0.011 0.012 0.013 0.018 0.020]
set increments 10
set nodeTag 2
set dofTag 1

## start procedure for feeding in
## Reverse Cyclic loading to the model by Disp. control
procRCycDAns $increments $nodeTag $dofTag $peakpts

# print the results at nodes
print node