PushOver Analysis on Shell Elements

[frconde91]

Hello,

I'm been trying to model a structure with shell elements on SAP2000 to perform a Push Over analysis. The SAP2000 features say that it can do it (check picture attached) but there is no tutorial or any explanation anywhere. It's quite urgent since I'm making my thesis and I can´t advance anymore without the capacity curve and the limit states of my building.

Problems/Doubts:

- The image that I attached shows hinges "becoming" plastic but I can´t define those hinges. By the image it seems that we have a bar element embedded into a shell element and the hinges are appearing both in the bar and shell. How can I do this?

- Fiber hinges are supposed to work only for frame elements?

- How can I use layered sections to induce nonlinearity creating hinges through the element?

- If I create new material and introduce myself the stress strain plot, would the hinges respond properly?

Much appreciated for any reply to this post, I guess there is a lot of more doubts to be discussed.

Best regards

 

[wannabeSE]

I am using my phone to reply and I text like an early boomer (poorly). But here is my attempt to reply.

First, this cite doesn’t like student posting.

CSI has an ETABS tutorial for nonlinear static (pushover) and nonlinear dynamic for a shear wall building with layered shells. SAP2000 uses same method for defining layered shells.

As far as I know, SAP doesn’t do hinges on shells, layered shells are required
. Equivalent frames may be possible, but I haven’t seen any tutorials. If you have access to ETABS Ultimate version, I think there are more options. Perform 3D may be another option (don’t know). Have you tried contacting CSI for help?

 

[frconde91]

Thank you for the answer.

If I define layered shells how can I check (after pushover analysis) in which state of plasticity my shell elements are? It's plausible to establish a maximum compression, tension and flexure stresses to compare with the results?

I only have stresses, displacements and capacity curve results. What I need is the limit states that a "normal" pushover analysis in a frame element gives us. It seems that in shell elements, the pushover analysis only loads the structure to the target displacement defined and with frame elements with user defined hinges he can provide the several limit states associated to the different evolution of plasticity on hinges.

I can´t or shouldn´t make an equivalent frame model to my structure because it's a composite building with exterior limestone masonry walls and internal wood walls and slabs.

And yes, I'm still a student performing my master thesis on seismic certification topic

Regards

 

[Shotzie]

Can you not call SAP customer support? I don't know if they would assist someone with a student copy of the software but it wouldn't hurt.

 

[frconde91]

I can´t, they don´t provide support to students unfortunately. They say that in the website

 

[frconde91]

Just found a solution, ETABS seems to be the only one who let you apply nonlinear hinges on wall panels.

Thank you for your answers