Effect of internal stiffeners on the vertical and lateral performance of concrete-filled L- and T-shaped steel columns

Subject Areas : Analysis of Structure and Earthquake

Mohamad Reza Jorabchi ¹ , mohamad reza oliaei ²

1 - Student
2 - PHD of Structures, Lecturer at Ramsar Azad University

Received: 2022-04-25 Accepted : 2022-08-26 Published : 2022-12-20

Keywords: Axial and shear performance, CFST, L-shaped section, T-shaped section, internal stiffener,

Abstract :

Steel columns filled with concrete with a special shape, mainly L-shaped, T-shaped and cross-shaped columns, are used as single columns or as boundary members of the shear wall, and in terms of structural design especially architecture, have been considered by many researchers and designers. Owing to their proper implementation in beam joints, they are receiving increasing attention in the world. These columns are often utilized in the residential and formal structures, however, due to heavy loads, such as those that may occur during severe earthquakes, they do not meet the requirements of high-rise buildings. There should always be more studies on the increasing of their performance. In this research, cold-rolled steel sections have been utilized for hardening, strengthening and straightening of the axial and shear performance of L-shaped and T-shaped steel columns filled with concrete. The research variables in this study are the internal stiffeners between the column sections, and the main purpose of this research is to numerically investigate the axial and shear performance of the concrete-filled steel columns with L-shaped and T-shaped cross-sections using Abaqus software. Also, in this study, it is determined that by adding steel sheets in the space between the columns, what kind of changes do axial and shear resistance, hardness, and ductility take? In the first stage, five L-shaped steel columns filled with concrete and five T-shaped columns by internal steel plates of different lengths and steel pipes under axial loading were analyzed numerically, and in the second stage, the same columns were loaded laterally and analyzed. The results indicate that the steel column filled with concrete in the T-shaped cross-section has a higher performance than the similar L-shaped cross-section, in addition, the percentage of growth or loss of performance of the samples compared to the base sample in the L-shaped and T-shaped sections is almost similar to each other. Also, the results exhibit that creating a hardener inside the section increases the stiffness and axial and lateral strength of the steel column filled with concrete. The hardening steel section has a great effect on the performance of L- and T-shaped steel columns filled with concrete so that reinforcing concrete filled steel columns with this method leads to an increase in load bearing capacity, increase in thrust ratio, ductility, prevention of local buckling in the steel wall and energy loss increases.