عنوان مقاله [English]
Due to the numerous advantages of the steel reinforced concrete (SRC) as a kind of composite columns, over the reinforced concrete and steel columns, its use has been widespread in recent years, especially in high-rise buildings. In these columns, due to the presence of steel profiles in the reinforced concrete, the buckling of the steel components is delayed or does not occur, which would significantly increase the bearing capacity of the cross-section. In this research, a numerical study was carried out with the aid of ABAQUS software to investigate some of the factors affecting the load capacity of SRC columns under eccentric loading. A finite element model was validated with the experimental results. A total of 39 SRC columns were analyzed for parametric study. Geometric and material variables such as steel ratio, slenderness column ratio, eccentric loading ratio, compressive strength, and stirrup spacing were evaluated on the bearing capacity of the SRC columns. Also, based on the calculated values, the axial and lateral load-displacement, and axial load-bending moment curves were plotted. The results showed that with the increase in the steel ratio and the reduction of the distance between the stirrups, the ductility index increased while with the reduction of the distance between the stirrups, the bearing capacity of the column increased slightly. Moreover, with the increase of the eccentricity, the bearing capacity of the columns is significantly reduced and the slope of the descending branch of lateral load-displacement decreases gradually. Moreover, if the column has less slenderness, the axial load-displacement curve has a more initial slope and with increasing slenderness, the lateral load-displacement has more nonlinear behavior due to increased second-order deformation. In addition, the axial load and stiffness of the composite column are significantly affected by the concrete compressive strength. The results also indicated that with increasing the eccentricity, the bearing capacity of the composite columns is reduced.