What is the openseespy error message 'R is negative in ReinforcingSteel::SetMP()' about?

[husayn]

Hello everyone,

I have written the code github repository link is available below:

https://github.com/husayn-mohammadi/01_cantilever

when I run the code for a cyclic pushover analysis, I get the message 'R is negative in ReinforcingSteel::SetMP()' and subsequently the analysis explodes. It doesn't result in a logical plot of hysteretic response.

Can anyone test my code and try to figure out what is wrong with it?
Thank you in advance for helping me.

Husayn,
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husayn@aut.ac.ir

[mhscott]

You should consider using other material models for your steel. ReinforcingSteel is very unstable.

[husayn]

You should consider using other material models for your steel. ReinforcingSteel is very unstable.

Thank you for your answer. Steel02 is much more stable than this, but in the literature I have seen a lot of people who have used ReinforcingSteel material model and none of them have convergence issues like me. I have changed the typeEle from forceBeamColumn to dispBeamColumn in my code and I had a very good effect; but yet in bigger target displacements I face that error. I want to know the meaning of that error (What does it say?).

[mhscott]

I'm not sure, but here is the line of source code: https://github.com/OpenSees/OpenSees/bl ... l.cpp#L941