Abstract
This study conducted cyclic loading tests where composite beams were linked to assembled concrete-filled steel tube (CFT) columns to examine how the connections behaved mechanically. The key factors included H-shaped steel PC composite beams with stress concentrated in the center, and concrete-filled steel tube SC composite beams with stress concentrated at the edges. Three samples were made, adding another factor: the thickness of the external diaphragm of the same PC composite beam. For the PC composite beam connection sample, stress was centered at the column's core. Conversely, for the SC composite beam connection sample, stress was focused towards the edges. Concerning the external diaphragm, the PC sample showed high stress at both edges, while the SC sample exhibited the opposite behavior. Comparing samples with different external diaphragm thicknesses, those designed within current codes exceeded nominal strength. However, samples designed outside of current codes didn't meet expectations, displaying variations in the connections' internal forces. In terms of stiffness degradation and energy dissipation capacity, samples designed within current codes and connected with PC composite beams performed better. The assessment of the seismic performance of the assembled CFT columns and their connections with the two types of composite beams suggests that they fulfill the requirements for special moment frames (SMF).