This study presents the results of nonlinear time history analyses of a multi-story building with structural system having highly ductile moment resisting frames composed of concrete filled composite columns and steel beams, which was designed per Turkish Code for Design and Construction of Steel Structures 2016 and Turkish Seismic Code for Buildings 2018. The nonlinear analyses were carried out with ETABS and OpenSEES using 11 earthquake ground motion records. The results of the analyses are evaluated on the basis of plastic rotations occurred in the beams and columns hinges. In addition, according to the values of plastic rotations, damage levels of beams and columns were determined and the seismic performance of the structural system of the building was also investigated. Shear forces acting on each floor (diaphragm forces) considered for the design of the diaphragm elements were also examined within the Turkish Seismic Code for Buildings 2018. The consistency between the analyses results from both computer softwares were comparatively assessed.