Proposals for Calculation of Bucking Coefficient for Concrete-Filled Steel Tube Columns

• Published in: IOP conference series. Materials Science and Engineering Vol. 262; no. 1; pp. 12047 - 12051
• Main Authors: Krishan, A L, Sagadatov, A I, Surovtsov, M M
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 01.11.2017
• Subjects: Coefficients; Deformation; Flexibility; Literature reviews; Mathematical analysis; Reinforced concrete; Reinforcing steels; Steel columns; Steel tubes
• ISSN: 1757-8981; 1757-899X
• DOI: 10.1088/1757-899X/262/1/012047

This paper demonstrates that the methodology currently standardized in Russia to factor in the flexibility of reinforced concrete components under extra-central compression produce results that satisfactorily match the experimental values; however, that only holds for the components with a flexibility of λ=40÷60. Given the complex stress state of the concrete core and the steel shell as well as due to the concrete-filled steel tube columns being prone to deformation, this method cannot be used to reliably calculate their load capacity. The literature review has revealed many researchers' suggestions to factor in the flexibility of concrete-filled steel tubes by means of the buckling coefficient that reduces the limit value of longitudinal force a short compressed element can take. We have analyzed the methods currently standardized in Europe and China as well as more advanced methods proposed by Chinese scientists. Calculating by these methods led to the results that excessively deviated from experimental values. By statistically analyzing a large volume of own and third-party research data as well as the data obtained by non-linear deformation computing, we have derived a new formula to determine the bucking coefficient depending on the relative flexibility.