Effects of Radial Imperfection on the Load Capacity of Round HSS Columns

Geometric imperfections such as radial imperfection, diamond shape, and local dimples could affect the buckling mode and load carrying capacity of axially compressed steel tubular columns. This paper experimentally investigates the effect of radial imperfection on the load carrying capacity of tubular columns. Test samples include 100 specimens with different values for diameter, length, thickness, imperfection amplitude and imperfection location. Considering applications of columns in buildings, bridges, and offshore jackets, diameter to thickness and slenderness ratios were varied between 20-90 and 17-181, respectively. Results showed that depending on the slenderness ratio and the severity of the imperfection, there was a significant difference between buckling loads of perfect and imperfect specimens.