Effects of debonding on circular CFST stub columns

• Published in: Journal of constructional steel research Vol. 69; no. 1; pp. 64 - 76
• Main Authors: Xue, Jun-Qing, Briseghella, Bruno, Chen, Bao-Chun
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.02.2012
• Subjects: Concrete filled steel tube; Concretes; Confinement; Debonding; Ductility; Finite element method; Mathematical analysis; Mathematical models; Parametric analysis; Simplified calculation formula; Structural steels; Ultimate load capacity; Concrete filled steel tube; Simplified calculation formula; Debonding; Parametric analysis; Ductility; Ultimate load capacity
• ISSN: 0143-974X; 1873-5983
• DOI: 10.1016/j.jcsr.2011.08.002

Core concrete subjected to confinement effect from steel tube is the main advantage of concrete filled steel tubular (CFST) column under compression. However, this beneficial composite action could be weakened even destroyed by debonding, which is almost unavoidable as a common phenomenon in CFST structures and has not been considered satisfactorily by current design codes. In this paper, the influence of debonding on circular CFST stub columns was investigated experimentally and numerically. The main experimental parameters were the debonding arc-length ratio, the confinement factor and the load mode. Meanwhile, the finite element models were implemented using the ABAQUS finite element software, of which the validity and accuracy were verified by test results. Utilising the finite element model, the parametric analysis was carried out to study the influence of the following parameters on the ultimate load capacity of debonding specimens: debonding arc-length ratio, debonding thickness and confinement factor. Based on the results of parametric analysis, a simplified calculation formula was proposed to calculate the ultimate load capacity of circular CFST stub columns with debonding. ► The influences of debonding on circular CFST stub columns were investigated by test. ► The FE models of debonding circular CFST stub columns were implemented using ABAQUS. ► The validity and accuracy of the FE models were verified by tests results. ► A parametric analysis was carried out to study the influence of debonding. ► A simplified formula was proposed to calculate the influence of debonding.