Investigating the Effect of Concrete Compressive Strength on Axial Performance of Double-Edged Steel Columns Filled with Concrete

In this research, the co-operation of steel and concrete in composite columns is considered. Using numerical modeling to study the behavior of these sections, a new type of composite sections named concrete-filled double-skin steel column is introduced. The factors affecting numerical simulation, which bring this simulation closer to the laboratory conditions, determine the axial resistance of the samples by changing the dimensions and geometry as well as the properties of the materials. The purpose of this thesis is to investigate the effect of concrete compressive strength on the axial performance of concrete-filled double-skin steel column CFDST concrete. A total of 20 samples with different parameters such as effects of concrete, loading capacity and width to thickness ratio on the strength of columns with square and round cross section in inner and outer walls were investigated by ABAQUS software. The results of the study showed that the loading capacity of CFDST columns under axial pressure increased by about 4% with increasing compressive strength of concrete in the inner wall. Also, studies showed that with increasing cross-section in the inner wall, the loading capacity in square columns increased by about 7% and decreased by about 3% in circular columns.