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Hi!
I have been trying to reproduce the model you proposed considering the lumped plasticity approach and using zero Length elements. I have not been able to obtain a similar moment-curvature for the bending-axial behaviour. I have followed the approach proposed in the webminar about modelling the platicity in RC frames. How did you define this material?
Also, regarding the plastic hinges behaviour, I saw that in the webminar, you checked the strees-time evolution of the fiber at both the bottom of the pier and the end of the spandrel. I have seen that the values of stress in the spandrel were near 0, despite the fact that the curve looked like it had some decays. Also, this was checked for the first stage analysis... So, I dont know if this can provide some info about the behaviour of the hinge. My question is, could it be possible to check if the plastic hinges have attained a certain level or if they have been activated? Is there a possible solution to check just the behaviour of the hinges during the analysis? For both modelling approaches?
Keep in touch.
Regards.

Hi mmc,

sorry for the late response.
For your first question:

I have been trying to reproduce the model you proposed considering the lumped plasticity approach and using zero Length elements. I have not been able to obtain a similar moment-curvature for the bending-axial behavior. I have followed the approach proposed in the webinar about modeling the plasticity in RC frames. How did you define this material?

The approach is exactly the same that you studied for the RC structure, it starts to be a bit more complicated for EFM because maybe you will need to repeat it for more than one section. What you do is you take your pier in a distributed approach, you extract a moment-curvature response from a simple gravity analysis, then try to match that moment-curvature with the uniaxial material law that you decide to use, remembering that you need to express the bending contribution in terms of moment-rotation. And then if you want to add shear behaviour too, the same way, remembering that in the distributed approach you have distributed shear (if you use an aggregator) shear - deformation, and in the lumped approach you have shear - shear drift relationship.

As for your second question. It depends on the uniaxial material that you choose to use to model your bending and shear behaviour. Hypothesizing that your shear behaviour is modelled with a Pinching4 or ModIMK, these materials do not have a setResponse() in the code, there is not a way to plot a damaging result or anything that can give you graphic information on the decay of the material. Therefore, the only thing you can do is plot time-stress and strain-stress relationships for the fibers in the distributed and finite length approach, or on the gauss points for the zerolength approach, and compare it which what you know is the capacity of your hinge,

Hope this helps,
let me know if you have more questions.
Francesca