Calculating Method Study and Parameter Analysis of Slender LCFST Columns Under Axial Loading

L-shaped columns composed of concrete-filled steel tubes (LCFST columns) connected by steel plates, which are important component to make sure the mono-column working together, were investigated under axial loading experiment with different width and thickness of connection plates. The relationships between load and longitudinal displacement, lateral displacement, longitudinal strains and transverse strains as well as failure mode are presented. Load carrying capacity of LCFST columns increased with the width and thickness of the connection plates increasing. In addition, the integrity of the specimen was improved with increase of thickness and decrease of width of the connection plates. Failure modes obtained from the finite element model were consistent with the phenomenon observed in the test. Besides, the parameters of slenderness ratio, dimensions of connection plate, and transverse stiffener spacing were analyzed. Finally, the calculating method of yield bearing capacity of axial compression was proposed based on the former analysis.