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MPCO recorder for moment curvature analysis

Posted: Wed May 08, 2024 10:00 am
by mike_oleary
Hi, I am trying to use the mpco recorder for a moment curvature fibre section analysis. I am not using this via stko but rather just TCL files. I have had good success with the recorder for models but I'm struggling with how to use it for moment curvature analysis. Unfortunately the documentation on the OpenSees wiki has nothing, so I'm a little stuck with what to do. Is there any documentation on using the recorder? (i.e. what are all the options available and how to use for a moment curvature analysis). If not it's there someone here that has used it for moment curvature analysis?

Re: MPCO recorder for moment curvature analysis

Posted: Wed May 08, 2024 10:30 am
by STKO Team
You can find the doc here:
https://asdea.eu/software/stko-documentation/

If you have issues, attach here your tcl file and we will have a look

Re: MPCO recorder for moment curvature analysis

Posted: Wed May 08, 2024 8:30 pm
by mike_oleary
I've attached a screen shot of the error I am getting and also an example file. Note that if the mpco recorder is removed and the node recorder used instead it runs fine (I couldn't seem to attach a text file).

Code: Select all

wipe

# Model

model Basic -ndm 3 -ndf 6

# Materials

uniaxialMaterial Concrete04 1 30000000 0.002 0.003 800000 0 0 0
uniaxialMaterial ElasticBilin 2 200000000000 0 0.0025 200000000000 0 0.0025

# Sections

section Fiber 1 -GJ 1000000 {
	fiber 0 -0.475 0.05 1
	fiber 0 -0.425 0.05 1
	fiber 0 -0.375 0.05 1
	fiber 0 -0.32499999999999996 0.05 1
	fiber 0 -0.27499999999999997 0.05 1
	fiber 0 -0.225 0.05 1
	fiber 0 -0.17499999999999996 0.05 1
	fiber 0 -0.12499999999999997 0.05 1
	fiber 0 -0.07499999999999998 0.05 1
	fiber 0 -0.024999999999999988 0.05 1
	fiber 0 0.025 0.05 1
	fiber 0 0.07500000000000004 0.05 1
	fiber 0 0.12500000000000008 0.05 1
	fiber 0 0.17500000000000002 0.05 1
	fiber 0 0.22500000000000006 0.05 1
	fiber 0 0.275 0.05 1
	fiber 0 0.32500000000000007 0.05 1
	fiber 0 0.3750000000000001 0.05 1
	fiber 0 0.42500000000000004 0.05 1
	fiber 0 0.4750000000000001 0.05 1
	fiber -0.4 -0.4 0.0012566370614359172 2
	fiber 0.4 -0.4 0.0012566370614359172 2
}

# Nodes

node 1 0 0 0
node 2 0 0 0

# Supports

fix 1 1 1 1 1 1 1
fix 2 0 1 1 1 1 0

# Elements

element zeroLengthSection 1 1 2 1 -doRayleigh False

recorder mpco D:\\temp\\nodempco.out -N displacement
# recorder Node -file D:\\temp\\node.out -precision 6 -time -node 2 -dof 6 disp

# Time Series

timeSeries Constant 1 -factor 1

# Time Patterns

pattern Plain 1 1 1 {
	load 2 1000 0 0 0 0 0
}

constraints Plain
numberer Plain
system UmfPack
test EnergyIncr 1E-08 10 0 2
algorithm Newton
integrator LoadControl 0 1 0 0
analysis Static
analyze 1    


# Time Series

timeSeries Linear 2 -factor 1

# Time Patterns

pattern Plain 2 2 1 {
	load 2 0 0 0 0 0 1
}

constraints Plain
numberer Plain
system UmfPack
test EnergyIncr 1E-08 10 0 2
algorithm Newton
integrator DisplacementControl 2 6 2.5E-05 1 2.5E-05 2.5E-05
analysis Static
analyze 100    


Re: MPCO recorder for moment curvature analysis

Posted: Thu May 09, 2024 11:15 am
by STKO Team
It's a problem with the zeroLengthSection: it does not format the output in such a way that the MPCO Recorder is able to understand the shape of the fiber section. We just changed the code and will do a Pull Request to the OpenSees Source code.

In the meantime, instead of a zeroLength section, use a unit-length beam element. In this way its rotation will be equal tot the curvature

Re: MPCO recorder for moment curvature analysis

Posted: Thu May 30, 2024 7:08 am
by mike_oleary
Thanks! Sorry I'm late to reply, I've been busy on other stuff since I first tried this and now am going to look back into switching over to the mpco recorder. I'll learn more once I use it, but maybe you'll have the answer for me. I'm curious how the stress/strains of fibres are recorded. If I recall correctly setting up some of the standard recorders to record fibres either requires an tag (which is not known in the TCL files) or using x,y coordinates (which I don't love either). Will reach fibre be recorded with some metadata about the fibre to provide some way to collerate where in the section it belongs?

Re: MPCO recorder for moment curvature analysis

Posted: Thu May 30, 2024 8:01 am
by kesavapraba
MPCO recorder option sends the results into a HDF5 database (you can see these files after the analysis) for the chosen options. For example, In the case of section.fiber.stress, the recorder identifies internally all the fibers using its algorithm and stores the data into HDF5 file. So, you are not required to provide either coordinates or fiber tag.

Re: MPCO recorder for moment curvature analysis

Posted: Tue Jun 04, 2024 12:42 am
by mike_oleary
Perfect, thanks

Re: MPCO recorder for moment curvature analysis

Posted: Tue Jun 04, 2024 7:31 am
by STKO Team
You're welcome