Seismic performance evaluation of Tubular Flange Beam (TFB) in moment resisting frames

The seismic performance of the beam-to-column connections is improved by creating inelastic behavior away from the face of the column. This paper presents a numerical assessment of an innovative ductile connection known as the Tubular Flange Beam (TFB) connection, utilizing the Abaqus finite element software. The TFB connection entails the substitution of a section of the beam with two tubes. In this study, 23 models, consisting of initial and parametric variety models are proposed and their impact on the moment–rotation behavior and plastic strain distribution of the connections is investigated under monotonic and cyclic loadings. The parameters consist of the tubes distance from the column, the length and section size of the beam and column, as well as the diameter and thickness of the tubes. The results demonstrated that changes in the tubes geometry had significant effects on the elastic stiffness and plastic moment capacity of the connection. Moreover, the effect of column size and length changes on the connection behavior was insignificant. Also, as the strength of the connection materials increased, the plastic moment capacity of the connection decreased, while the elastic stiffness of the connection did not change much. In addition, the TFB connection in comparison with the RBS and traditional welded beam to column connections has consistent hysteresis curve and effectively concentrates plastic strains within the reduced zone.