Techno Press
Techno Press

Steel and Composite Structures   Volume 29, Number 1, October10 2018, pages 77-90
DOI: http://dx.doi.org/10.12989/scs.2018.29.1.077
 
Composite action of concrete-filled double circular steel tubular stub columns
Liping Wang, Xing-xing Cao, Fa-xing Ding, Liang Luo, Yi Sun, Xue-mei Liu and Hui-lin Su

 
Abstract     [Full Text]
    This paper presents a combined numerical, experimental, and theoretical study on the behavior of the concrete-filled double circular steel tubular (CFDT) stub columns under axial compressive loading. Four groups of stub column specimens were tested in this study to find out the effects of the concrete strength, steel ratio and diameter ratio on the mechanical behavior of CFDT stub columns. Nonlinear finite element (FE) models were also established to study the stresses of different components in the CFDT stub columns. The change of axial and transverse stresses in the internal and external steel tubes, as well as the change of axial stress in the concrete sandwich and concrete core, respectively, was thoroughly investigated for different CFDT stub columns with the same steel ratio. The influence of inner-to-outer diameter ratio and steel ratio on the ultimate bearing capacity of CFDT stub columns was identified, and a reasonable section configuration with proper inner-to-outer diameter ratio and steel ratio was proposed. Furthermore, a practical formula for predicting the ultimate bearing capacity was proposed based on the ultimate equilibrium principle. The predicted results showed satisfactory agreement with both experimental and numerical results, indicating that the proposed formula is applicable for design purposes.
 
Key Words
    concrete-filled double circular steel tubular (CFDT) stub columns; composite action; ultimate bearing capacity; ductility index; strain ratio; diameter ratio
 
Address
(1) Liping Wang, Xing-xing Cao, Fa-xing Ding, Liang Luo, Yi Sun, Hui-lin Su:
School of Civil Engineering, Central South University, Changsha, 410075, P.R. China;
(2) Liping Wang, Fa-xing Ding:
Engineering Technology Research Center for Prefabricated Construction Industrialization of Hunan Province, Changsha, 410075, P.R. China;
(3) Xue-mei Liu:
School of Civil Engineering and Built Environment, Queensland University of Technology, Brisbane, QLD 4001, Australia.
 

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