Incidents such as fires, explosions, and impacts may cause progressive collapse of building. Since the 20th century, as terrorist activities in the world have been increasing year by year, experts and scholars around the world have begun to pay attention to the formulation of building collapse prevention codes and structural progressive collapse resistance. At present, Concrete filled steel tube column (CFST)-steel beam joints with outer ring plate have been widely used in engineering examples. However, outer ring plates occupy a large amount of building space due to welding on the outer wall of steel tubes, which affect the function of buildings, and CFST-steel beam joints with through-center construct, that is, the steel beams are wholly or partially passed through the core concretes and the steel tubes, which greatly save the use space of the buildings. In order to study the mechanism of CFST-steel beam joints with through-center construct under progressive collapse conditions, ABAQUS finite element software was used to establish five CFST-steel beam joints with through-center construct and one fully welded joint models. The resistance mechanism, deformation modes and internal forces of the joint were investigated,and the capability of progressive collapse was evaluated. The results showed that the failure mode of CFST-steel beam joints with through-center construct can be divided into two types, the collapse failure mode at the beam and the collapse failure mode at the column. The collapse failure mode at the column has better ductility and bearing capacity, but with instability. The vertical bearing capacity of the joints is mainly provided by the bending mechanism and the catenary mechanism. The bending resistance mechanism provides the early resistance and the catenary mechanism determines the ultimate bearing capacity at the later stage. The new CFST column-steel beam joint with through-center structure has good capability of progressive collapse resistance, and its index of progressive collapse resistance of joint is higher than that of the other joints with collapse failure mode at the beam.
