A Numerical Modelling for Seismic Behavior of Frames with CFST Composite Columns and Torsional Semi-Rigid Connection

Concrete filled steel tubes (CFST) are widely used in engineering structures due to their high strength, ductility, and flexibility and also their easy construction and good economic aspect. Using the connection plates with the blind bolts in these systems can reduce the issue of weld breakage and considerably increase the seismic performance of rigid structures. This research examines and models a new semi-clamped beam to column connection using the finite element method. The main features of this connection are the use of an end plate that connects the beam to the column flange. The numerical analysis of the seismic behavior and failure modes of CFST members that have blind bolts with a semi-rigid connection (bolted with threaded rods) have been studied with the Abaqus software. This examination showed that using double bearing plates and thicker covering plate can be useful in improving the seismic performance of the connection up to 20 percent