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Plastic Hinges

Posted: Sat Dec 07, 2019 12:38 pm
by Ali shafiee
Is there a way to see plastic hinges in elements of a structure after the analysis?
and should we model the structure in "Concentrated Plasticity" to see the plastic hinges or we can see them in a common "Distributed Plasticity"(with Fiber elements) model aswell?

*Thanks in advance*

Re: Plastic Hinges

Posted: Sat Dec 07, 2019 11:27 pm
by MassimoPetracca
When you want to see the progressive formation of plastic hinges, you can simply do a gauss-plot in the post-processor using the curvature as the result. Why? when a plastic hinge appears in a point, the curvature at that point will grow soon, making the particle (gauss-plot) at that point larger then others.
  1. do your model with either concentrated or distributed plasticity approach
  2. in the mpco recorder, ask for the proper element result that will give you the curvature (distributed case) or rotation (concentrated case) at the integration points. For example in the distributed case you can choose "section.deformation"
  3. in post-process do a gauss-plot, and choose one of the 2 curvature components as a result.

Re: Plastic Hinges

Posted: Thu Mar 12, 2020 5:48 pm
by NicolaTarque
I am analyzing a pushover analysis of a 2d frame (3 stories). We have already put the option to see the gauss points at the output.
My question is regarding to visualization of the curvature or rotation. I am using plastic hinges where I enter data of Moment vs Rotation according to Lignos and Krawinkler. That means that my rotation is the curvature times a plastic length (normally 050 of the beam depth).
When I select the option SectionDeformation I can choose also Kappa_Z, but I think it is curvature, right?
Then, if I multiply kappa_Z times 0.5 the bema depth, should I have the same rotation values that i entered in the Lignos and Krawinkler model? I think yes.
Is there any option to see directly Rotation values at a given GP?