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Manually record fiber element

Posted: Sun Sep 06, 2020 7:42 pm
by yuweihwang
Hello folks,

Will the recorder commend change if I used STKO to build the fiber element?
I mannualy add "eval "recorder Element -file Fuse.out -time -dT -ele 17 section 5 fiber 0.0 -0.15 stressStrain" in the script to
record the stress-strain response of the fuse. I also checked the location (y,z) on the section. However, the result is always blank.
Is there any other way to record the stress-strain response of the fiber?

Best,
Yu-Wei Hwang

Re: Manually record fiber element

Posted: Mon Sep 07, 2020 9:09 am
by STKO Team
STKO does not change the commands you can use in OpenSees.
By the way, STKO uses a 0-based indexing for gauss points and fibers, while OpenSees uses a 1-based indexing for gauss points and 0-based for fibers.

So in your case it should be:
recorder Element -file Fuse.out -time -dT -ele 17 section 6 fiber 0.0 -0.15 stressStrain
or
recorder Element -file Fuse.out -time -dT -ele 17 section 6 fiber 3 stressStrain

if the first does not work it means that the location is not correct

Re: Manually record fiber element

Posted: Fri Feb 19, 2021 5:04 am
by netoprax
I have the same issue
I am sure I am providing the right element, section and fiber number (and coordinates)
unless I misunderstood something
is there anyone willing to help?
thanks

Re: Manually record fiber element

Posted: Fri Feb 19, 2021 5:16 am
by netoprax
if anyone come across this post in the future:
removing "-time" worked for me to retrieve to stressStrain.

Re: Manually record fiber element

Posted: Mon Mar 25, 2024 6:33 am
by Lei Lei
Dear STKOteam,

I also met this problem and I didn't use MPCOrecorder.

I used a custom script to record the fiber stress-strain results for a zero-length section element like "recorder Element -file Stress-Strain.txt –time -ele 35 section 26 fiber 13.5 0.0 11 stressStrain".

However, it didn't work and the Stress-Strain.txt was blank.

I also tried with ""recorder Element -file Stress-Strain.txt –time -ele 35 section fiber 13.5 0.0 11 stressStrain"
and "recorder Element -file Stress-Strain.txt –time -ele 35 section fiber 13.5 0.0 stressStrain"
and "recorder Element -file Stress-Strain.txt -ele 35 section 26 fiber 13.5 0.0 11 stressStrain".

All the efforts were in vain.

Looking forward to your reply.

Re: Manually record fiber element

Posted: Mon Mar 25, 2024 7:30 am
by kesavapraba
Hi, Can you please share a minimal example model for debugging?

Re: Manually record fiber element

Posted: Mon Apr 08, 2024 5:29 am
by Lei Lei
Thanks for your reply!

I have done it with the help from https://opensees.berkeley.edu/OpenSees/ ... al/259.htm

And for the zerolengthsection element, the number of section should be removed, just like 'recorder Element -file ele1sec1StressStrain.out -time -ele 1 section fiber $y $z <$matID> stressStrain'.

Re: Manually record fiber element

Posted: Mon Apr 08, 2024 9:09 am
by kesavapraba
There is a long dash before "time", you should use small dash instead, this can be a reason for the first two cases. However, your last case should have worked without "-time" option, Not sure why in that case! Can you try following:
recorder Element -file StressStrainCurve.out -time -ele 35 section 26 fiber 13.5 0.0 11 stressStrain