Afsaneh Ghorbanzadeh - M.Sc. student, Department of Civil Engineering, Islamic Azad University of Mashhad, Iran
Amir R. Masoodi - Lecturer, Department of Civil Engineering, Ferdowsi University of Mashhad, Iran.Lecturer, Department of Civil Engineering, Islamic Azad University of Mashhad, Iran
Seyed Masoud Riazi-Mazloomi - Assistant Professor, Department of Civil Engineering, Islamic Azad University of Mashhad,Iran

Concrete-Filled Double Skin Tube (CFDST) columns includes two thin-walled steel tubes between which concrete is filled. This type of columns has been widely developeddue to high compressive strength and good seismic behavior. This paper is dedicated to investigate the compressive behavior of CFDST short columns in which differentgeometric properties are considered for the section. The cross-section of the column is assumed to be circle. To fulfill this, different cases including ۱۴ models are considered by using a well-known Finite Element Method (FEM) program. In these models, the effect of various parameters including internal and external diameter, thickness of steel internal and external tubes, and also thickness of concrete are studied numerically on the compressive capacity of the CFDST columns. It is worth mentioning that the proposed modeling is validated using a comparison study between the obtained results and the responses presented for benchmark problem. For each case, the compressive load-axial displacement curves are provided along with Von-Mises stress contours as well.

Compressive strength, CFST, circular section, thickness, short column, finite element method