asdeasoft.net

try this: I changed:

• Penalty a bit lower 1.0e16
• The damping proportional to the initial stiffness and not the tangent (nonlinear) stiffness
• Integration scheme = TRBF2 -> it adds some numerical damping

Is muh better!! But still very noisy and compact..
Is there any other thing that can be changed so I can get a curve more like this (non linear analysis):

You should check your materials.

First you are monitoring the Y direction.
You zeroLength for bearings are fixed (EqualDOF) along the Y direction so they cannot provide nonlinearity.
The only other source are the piers, but if you look at their values only few rebars are just reaching the yielding point. But all the piers are nearly elastic.

In the image you posted there is a huge source of dissipation. Looking at the image it seems it comes from bearings. so you should double check the values you put in those isolators if you think that seismic action (3 m/s^2) is able to generate such energy dissipation

Morning!

I checked everything and even tried different materials and still my nonlinear analysis is not as is should be...
The value of dt is related to the time of the spectrum or is arbitrary?
And why can't the base node selection not have the top nodes from the zerolength element? I'm getting stressed because of the pushover not having a proper curve and can't find the solution.
I'm sorry for insisting, but I really need this analysis to work

Sorry but the only way is to understand what is the curve you are expecting, what strength value etc...
Once you know (also with the help of hand calculations) what you should expect from your global results, try to have a look at the model and see what component is not giving the right response.

There is not way for us to help you in this regard, it depends on the specific materials/bearings/etc.. you need to model