Compressive performance of an innovative thin-walled L-shaped steel column

In this paper, an innovative L-shaped steel column, fabricated by thin-walled square steel tubes (LFTST column), is proposed, suitable for low-storey residential buildings. The LFTST column, constructed using three column limbs and interconnected rectangular steel tubes via self-drilling screws, offers benefits such as effortless installation and ecological sustainability. However, there is a lack of relevant understanding regarding the mechanical performance of the LFTST column, such as its compression behavior. This study therefore investigated the compression behavior of such LFTST columns subject to axial and eccentric load. Five full-scale LFTST column experiments were carried out with different eccentricity and the arrangement of inter-limb connections, and their compression behavior was obtained and evaluated including failure modes, the bearing capacity, loaddisplacement response, and strain development. Subsequently, the finite element (FE) modeling of LFTST columns were established and validated by comparisons to experimental results including the load-displacement responses and ultimate bearing capacity, Then parameter analysis was further conducted to investigate the effects on the compression behavior of such LFTST columns, where the eccentricity distance, the thickness, height and number of the inter-limb connections were considered in the FE modelings. In addition, the calculation formula was derived to estimate the ultimate bearing capacity of the LFTST columns based on the double coefficient product method, exhibiting good agreement with the experimental and FE results.