Question:
I modeled a two-span reinforced concrete beam in Abaqus using the Concrete Damaged Plasticity (CDP) model for concrete and reinforcement bars for steel. Material properties and interactions were defined carefully, and the analysis was performed with a static step.

When I compare the results with the experimental test, the deflection in the Abaqus simulation is much smaller than the measured deflection under the same load.

My question:
Where could the problem be, and how should I adjust the concrete model in Abaqus so that the numerical results get closer to the experimental behavior?