City Research Online

Abstract

This paper describes the experimental and numerical study on the axial compressive behaviour of circular-in-circular concrete-filled double-skin steel tube (CFDST) stub columns with large void ratio. Nine specimens with various void ratio (Rv), diameter-to-thickness ratio of outer tube and compressive strength of concrete were tested under axial compression. The failure patterns, load versus displacement (strain) relationship, ultimate capacity and elastic composite stiffness of the specimens were investigated. The experimental results show that all specimens have good structural performance. The typical failure patterns of this new type of columns include local buckling of outer or inner tubes and crushing of concrete infill at the primary buckling locations of both tubes. It is observed from the tests that, there are three key stages in the load versus displacement (strain) relationship, namely: approximative elastic, elastoplastic and nonlinear post-peak, and with the augment of Rv and Do and the reduce of fcu, the ultimate capacity and elastic composite stiffness of the specimens decrease. Apart from tests, a finite element (FE) model was developed to further study the axial compressive behaviour of circular-in-circular CFDST stub columns with large void ratio, and the model was validated against the experimental results. Finally, a simplified analytical model to predict the ultimate capacity of circular-in-circular CFDST stub columns with large void ratio was developed, and the accuracy of the model was verified by the available experimental results. It can be used by the practising engineers in the future design of this type of columns.

Publication Type:	Article
Additional Information:	This article is published in Journal of Constructional Steel Research, Elsevier. © 2021. This manuscript version is made available under the CC-BY-NC-ND 4.0 license https://creativecommons.org/licenses/by-nc-nd/4.0/
Publisher Keywords:	circular-in-circular CFDST stub columns; large void ratio; axial compressive behaviour; experiments; finite element (FE) model; ultimate capacity prediction
Subjects:	T Technology > TA Engineering (General). Civil engineering (General)
Departments:	School of Science & Technology > Engineering
SWORD Depositor:	Symplectic Administrator

Export

Downloads