Pushover Analysis

[STKO Team]

This is exactly what I obtained, and if you superimpose it to the dynamic response, they will have not the same slope

[sribeiro]

This is exactly what I obtained, and if you superimpose it to the dynamic response, they will have not the same slope

Sorry, I'm confused
But I want it to be similar, to have "sure" that I'm doing the analysis well.
And with that selection set I can't even get the capacity curve..

and you will see that the pushover curve is actually much higher (same stiffness of your dynamic) because previously you were missing some reaction from those nodes

When you mentioned it, I though you meant that I would obtain a capacity curve with a higher stiffness.
I'm not understanding

[sribeiro]

Correct me if I'm wrong but shouldn't I get a curve similar to the one in pink?
At least is the idea I have, or have a TH analysis that follow the blue line I have.. I just saw some examples and they were matching.

[STKO Team]

No, if you look at your pushover results with the correct nodes for extracting all the reactions you will see a much higher pushover curve (if I remember correctly the shape was nearly linear and it reached values of about 400k).
Now if you put that curve under the TH response (always with the correct selection set) you will see that they match, at least in terms of stiffness, but your input motion is not strong enough to push it to the pushover displacement

[sribeiro]

What should I correct then so I can have a better analysis? Is the material properties? Is the way I'm doing the pushover?
I really need to do this analysis and compare both, inclusive the influence that the bearing system has in the bridge displacement when exposed to seismic actions.

[STKO Team]

First do the comparison using the correct set of nodes for reactions and let's check that they match (i.e. the TH results are following the slope of the pushover).

Then, if you think your pushover analysis (and so also the TH) is overestimating the capacity of the bridge, you can start looking at the results (moment-curvature, stress and strains, forces in the bearing system, etc..) to check if there is the need to change some parameters

[sribeiro]

First do the comparison using the correct set of nodes for reactions and let's check that they match (i.e. the TH results are following the slope of the pushover).

I did this, and you're right, it matches.

[sribeiro]

I have another question related to this topic: on my TH analysis I followed the youtube tutorial about the Non linear TH analysis of a bridge.
I have all the settings the same way as the example, but still can't have the same type of nonlinear analysis as the example.
I've checked, I am comparing the same selections sets, I also checked all the commands and still, my curve has a lot of noise and is not as defined as the one from the example.

Do you know what the mistake can be?

(image: tutorial graph example on the right side)

[STKO Team]

I did this, and you're right, it matches.

Ok perfect. That's a starting point.

I have all the settings the same way as the example, but still can't have the same type of nonlinear analysis as the example.

Just one clarification: Is it the same model?

[sribeiro]

Just one clarification: Is it the same model?

Is the same model I presented before.
I made it following the youtube tutorial, so connections are equal, material props very similar. Changes the geometry (shorter bridge) and the sw loads and the bearing props.