Stiffness of Concrete-Filled Thin-Walled Steel Tubular Slender Columns

Abstract

Concrete-filled thin-walled steel tubular slender columns are studied in this paper to evaluate their stiffness. The slender columns have various steel tube thicknesses, length/diameter (width) ratios, and concrete compressive strengths. The columns are loaded by axial and eccentric loads. Two experimental tests of the slender and stub columns are described. Also, the finite element software ABAQUS is utilised to simulate and analyse the columns. The tested columns are simulated taking into account all their features in the tests to verify the simulation of the columns. The simulation results are compared with the tests results which reveal that good agreements exist between them. Thus, the proposed simulation method of the columns is verified. In order to assess the stiffness of the columns under different conditions, various load eccentricities (0 mm, 25 mm, and 50 mm), cross-sectional configurations (circular, rectangular, and square), and steel tube thicknesses (2 mm, 3.35 mm, and 5 mm) are adopted for the developed columns. The columns are simulated and analysed based on the verified simulation method considering the mentioned conditions. As a conclusion, the stiffness of the columns is generally reduced by the increase of the load eccentricity from 0 mm to 25 mm and 50 mm. Further, more uniform distribution of the stiffness is witnessed for the columns with lower eccentricities. In addition, the enhancement of the load eccentricity increased the reduction slope of the stiffness graph for the columns. Although the initial stiffness of the circular column is slightly lower than the rectangular and square columns, the stiffness has more uniform distribution which is preferred. Larger stiffness is achieved for the columns by increasing the steel tube thickness from 2 mm to 3.35 mm and 5 mm.

Effects of eccentric loading on performance of concrete columns reinforced with glass fiber-reinforced polymer bars

“…As a result, many standards, such as ACI 440 3 , restrict designers from utilizing GFRP bars in compression members, although CSAS6-06 13 has not discussed this compressive behavior of GFRP bars. Limited research works have been done on the use of eccentrically loaded columns reinforced with FRP 14 – 28 . Furthermore, few studies have assessed the behavior of GFRP bars embedded in concrete columns under pure axial load, but minimal experimental and numerical data exist on the response of longitudinal and transverse GFRP-RC columns under eccentric, concentric, and flexural loadings.…”

“…Furthermore, few studies have assessed the behavior of GFRP bars embedded in concrete columns under pure axial load, but minimal experimental and numerical data exist on the response of longitudinal and transverse GFRP-RC columns under eccentric, concentric, and flexural loadings. Steel reinforcing used in bridge piers is prone to corrosion due to exposure to chloride attack from flowing water 14 – 21 . To study the serviceability of GFRP bars, the number of field tests performed and GFRP bars exposed to harsh environments did not show any signs of degradation during 6–8 years 20 .…”

Numerical Analysis of Sectional Shape Effect on Behavior of Short Concrete Columns

“…Therefore, their failure leads to the collapse of the entire construction [3]. Failure of short columns occurs due to material yielding either concrete crushing or rebar yield [4].…”