Best regards,
Michaela Vaitova

You would better upload your model into a cloud and share link here. Otherwise no one can tell why you have such result

I’m using atena 3D to model continuous beam with two spans. I have a strange matter, because of having a symmetry beam, I model the half length for one span and got max deflection 35mm but when I model the total length, there is  a difference in results and got 20 mm deflection, noting the same conditions break criteria and the same error limit for both cases. So I hope to help me in that matter please, what are the reasons for that??

Thanks