EXPERIMENTAL STUDY ON BOX-T HYBRID SECTION COLUMNS UNDER COMPRESSION
Ziqian Zhang 1,2*, Gang Shi 1,2
1 Key Laboratory of Civil Engineering Safety and Durability of China Education Ministry, Department of Civil Engineering, Tsinghua University, Beijing, China
2 Beijing Engineering Research Center of Steel and Concrete Composite Structures, Tsinghua University, Beijing, China
With the building higher and higher, the column section becomes larger and larger so that a part of the column protrudes indoors, which reduces the usage area and affects the building beauty. Therefore, box-T hybrid section columns have been designed to hide themselves inside the wall to solve this problem. However, there has been no study of this kind of special-shaped columns yet. In this paper, five column composed of square hollow section (SHS) and welded or rolled T-section steel, with four of them under axial compression and one of them under eccentric compression, were conducted to study the overall buckling and distortional buckling behavior of box-T hybrid section columns. Material properties were also obtained by tension coupon tests for different components of the columns. Initial geometric imperfections, including both local and overall geometric imperfections, were measured by 3D scanner prior to the tests. With knife hinges adopted as the pinned-end of the columns, buckling deformations and capacities were investigated. Besides, the buckling capacity results of axial specimens were compared with the design curves according to Chinese code.
Steel structure; Special-shaped column; Box-T hybrid section; Overall and distortional buckling; Compression test