The use of concrete-filled steel tube (CFST) columns is highly encouraged nowadays in modern multistory structures. The major reason is the extensive resistance offered by the hollow steel column to high compression. Nevertheless, further studies and data are desirable to exhaustively characterize these members and their connections to other members, such as beams. This paper investigated the behavior of concrete-filled columns connected to I-beams by through plates. Three simple types of plate connections (easy to assemble and construct) were proposed and evaluated. The behavior of these connections was examined under static loading by using advanced finite element based software (ABAQUS). The modeling techniques used in this study were validated by comparing the numerical results of a through plate connection model with the results of two relevant experimental studies. The proposed connections were classified as semi-rigid connections according to Eurocode-3. These connections were able to move the plastic hinge away from the column panel zone. The maximum plastic rotations of all connection types were greater than 40 mrad. The failure mode, and moment-rotation curves of the concrete-filled column to steel beam connections were discussed based on numerical results. The influence of through plate material and through plate thickness were evaluated via a parametrical study.

Box steel columns have significant advantages compared with H-columns. However, box steel columns have the detrimental tendency of developing a plastic hinge at the column panel zone due to stress concentration. One of the methods for moving the concentration of the stresses at the column panel zone is to use a reduced beam.Nevertheless, a reduced beam decreases the capacity of the beam. This paper proposes a solution to the plastic hinge location without reducing the capacity of the beam. In this study, 106 connection configurations were numerically investigated using ABAQUS software. Two relevant experimental studies were used to validate the modeling techniques. The proposed joint was classified as semi-rigid and full strength according to Eurocode-3. To predict the cyclic behavior of the proposed connection, analytical simulation was performed using a Matlab program that uses the Richard and Abbot function. The program was able to accurately reproduce the connection behavior. Through parametric studies, the influence of plate thickness, column, and beam geometry on the connection's initial stiffness and moment resistance was examined. Finally, by using regression analysis, linear functions capable of predicting the initial stiffness and moment resistance of the connection were proposed.

In recent years, steel or composite beam-column connections have drawn increasing praise due to the rapid development of assembled steel structures. However, limited researches have paid attention to the analytical behaviour of square hollow column-beam joints. This work presents a numerical study on the static and cyclic behaviour of the connections between a square hollow steel column and I-beam. Finite element analytical modeling of the joint was performed considering complex contact interactions and material models. Six different connections were evaluated by using ABAQUS. The modeling techniques used in this work, including the mesh and element types, the material properties, and the contact elements, were validated by comparing the numerical results of a through plate connection model with the experimental study results. Good agreement between the test and analytical results was observed in terms of the failure modes and the hysteretic behaviour. The failure mode, moment-rotation curves for hollow steel section (HSS) column to steel beam connections were discussed based on numerical results.