Seismic behaviour of concrete-filled steel tubular columns with internal H-section steel under pure torsion and compression–torsion loads. (1st August 2020)

• Record Type: Journal Article
• Authors: Pi, Zheng-Bo; Su, Meni; Peng, Yuan-Yuan; Wang, Yu-Hang; Luo, Wei; Lan, Yong-Sen
• Is Part Of: Engineering structures. Volume 216(2020)
• Publication Date: 2020-08-01
• Subjects: Compressive torsional capacity -- Concrete-filled steel tube columns -- Energy dissipation capacity -- Torsional behaviour -- Torsional stiffness degradation -- Shear capacity of steel; Structural engineering -- Periodicals; Structural analysis (Engineering) -- Periodicals; Construction, Technique de la -- Périodiques; Génie parasismique -- Périodiques; Pression du vent -- Périodiques; Earthquake engineering; Structural engineering; Wind-pressure; Periodicals; 624.105
• DOI: 10.1016/j.engstruct.2020.110761
• Languages: English
• ISSNs: 0141-0296

Abstract

Highlights: Seismic performance of H-CFST columns under cyclic torsional and compression–cyclic torsional loads is investigated. Two types of H-CFST columns under cyclic pure torsion and compression-torsion are tested. Shear capacity of steel and concrete under combined normal and shear stress conditions is firstly studied. Design methods of torsional capacities of H-CFST columns under cyclic pure torsion and compression-torsion are proposed. Abstract: Concrete-filled steel tube (CFST) columns have been widely used in the construction industry because of their excellent compression capacity and torsion resistance. Regarding traditional CFST columns, the H-CFST column with an additional H-section steel member embedded in the core concrete provides improved fire and compression resistance. In this study, the seismic performance of nine H-CFST columns under cyclic torsional and compression–cyclic torsional loads was experimentally analysed. In the experiments, the failure mode, torque versus torsional angle hysteresis, torque versus torsional angle skeleton, torsional stiffness degradation, and energy dissipation capacity were determined. The hysteretic curves of the H-CFST columns under torsion were relatively plump in shape and exhibited no 'pinching' phenomenon, and the torsional stiffness of the H-CFST columns under unloading and reverse loading was approximately equal to the initial torsional stiffness. In addition, the applied compression had remarkable effects on the torsional capacity, torsional ductility, torsional stiffness, and hysteretic loop energy dissipation of the H-CFST columns. The shear capacities of the steel and concrete under normal stress or combined normal and shear stress were determined based on the latest theories and test results. Moreover, design method for the determination of the torsional capacity of H-CFST columns under compressive torsion is proposed based on the test results, and the theoretical contribution ratio of the H-section steel, steel tube, and concrete in the H-CFST columns to the torsional capacity was determined.