I am currently conducting research on the numerical modeling of reinforced concrete columns using Abaqus, with a particular focus on simulating their lateral load–displacement behavior. I think you have a potential to help with this issue, I truly appreciate your help.
Problem statement
While attempting to replicate a numerical model similar to those presented in published studies, I encountered an issue related to the initial stage of the load–displacement response. Specifically, the initial stiffness of my model appears significantly lower than expected when compared to experimental results, although the overall behavior and ultimate capacity show reasonable agreement. I have attached a picture of the problem with the red arrow.
I have made several attempts to adjust material properties, boundary conditions, and loading procedures. However, the discrepancy in the initial portion of the curve still persists.
I would greatly appreciate any guidance you could provide regarding the possible causes of this issue, particularly whether it might be related to modeling assumptions, interaction definitions, or load application techniques.
