Design of L-shaped and T-shaped concrete-filled steel tubular stub columns under axial compression

• Published in: Engineering structures 2020-03, Vol.207, p.110262, Article 110262
• Main Authors: Zheng, Yongqian, Zeng, Shaoxi
• Format: Article
• Language: English
• Subjects: Axial compression; Building codes; Civil engineering; Columns (structural); Composite structures; Compression; Compressive stiffness; Compressive strength; Computer simulation; Concrete-filled steel tubular columns; Design; Finite element method; Finite element models; Iron; L-shape; Mathematical models; Stiffness; T shape; Ultimate strength; Ultimate tensile strength
• ISSN: 0141-0296; 1873-7323
• DOI: 10.1016/j.engstruct.2020.110262

•Finite element models are developed for L-shaped and T-shaped CFST stub columns.•Unstiffened, stiffened and multi-cell cross-section forms are investigated.•A parametric study of 804 examples are performed.•Existing design models are assessed for special-shaped CFST columns.•New design models for compressive strength and stiffness are proposed. L-shaped and T-shaped concrete-filled steel tubular (CFST) columns are becoming attractive to researchers and engineers owing to their advantages of avoiding column protrusion from walls and they can save space. In addition, these columns can be used as corner and edge columns in civil engineering applications. Numerous research studies have been conducted on the behaviour of L-shaped and T-shaped CFST columns under axial compression; however, the design methods require further investigation. In this study, finite element (FE) models were developed to simulate the axial behaviour of unstiffened, stiffened, and multi-cell L-shaped and T-shaped CFST stub columns. The FE models were verified by the experimental results of 103 specimens collected from the literature. A parametric study of 804 examples covering a wide range of parameters was conducted based on the FE models. Predictions of the ultimate strength using Eurocode 4 and a previously reported design formula were compared with the FE results, in which unsatisfactory deviations were observed. New design models for the axial compressive strength and the stiffness were proposed by performing regression for different types of L-shaped and T-shaped CFST stub columns.