asdeasoft.net

Hello!

I am modeling a pushover anaylsis for a fiber section using concrete07 and steel02. I am using data from the PEER data base (https://nisee.berkeley.edu/spd/servlet/ ... tml&id=346) for column "A2". i have got pretty good results but there is a weird initial spike in the low displacement region.

I have attached the model and the data that i got. what could be causing this?

You have to understand exactly the behavior of your specimen at the initial stage.
There can be many factors why its initial behavior is softer than your model: bar-slip, initial cracking, different initial modulus, imperfection in the constraints, wrong tensile strength, etc...