Effects of Section Properties on Structural Behaviour and Failure Mode of Built-Up CFS Columns

Abstract

Abstract Built-up CFS column is a type of structure that can be classified as an industrialized building system. This column has been widely used in the construction industry. It has relatively lightweight, easy to fabricate and provide efficient installation, thus suitable for the construction with difficulty inaccessibility. However, the main issue that arises from the built-up CFS column is its bearing capacity. The ultimate strength and displacement of the built-up CFS column are prominently governed by its section properties such as size and thickness. Therefore, this study intends to investigate the effects of section properties on the structural behaviour and failure mode of built-up CFS columns. The built-up CFS column was modelled in the three-dimensional using WELSIM, taking into account the nonlinearities of geometry, material criterion and contact surface. It was found that the built-up CFS column attains ultimate strength of 53.33 kN to 210.6 kN and displacement around 1.33 mm to 2.98 mm. When the size and thickness of square hollow sections are increased, the ultimate strength increases simultaneously but the displacement shows a decrement trend. Under compression force, it was observed that the built-up CFS column suffers distortional and flexural buckling as well as connector and stiffener failures.