Hello, I have completed a full transient analysis so steel frame with EQ acceleration applied to mass of the structure while keeping the supports fixed. I tried to plot the displacement of the 1st floor with the shear force of the steel column. But I didn't get the proper restoring force-displacement relationship. It looks that there is hysteretic behavior but with a lot of transient noise how to reduce it? Also, to increase the mass I increased the density of the beams and didnt use MASS21. my steel beam model is BEAM189. Hope if there is someone who can help me on this one? I also applied the same accleration to a fixed column and its results was close to my expectation. Is there something I am missing between SDOF and MDOF structures?

I have also attached the single column reaction force-displacement curve here