Experimental and numerical investigation on the buckling behavior of corroded CST under axial compression

Abstract

To examine the local buckling performance of Q345B circular steel tubes (CST) after corrosion, 20 specimens with varying degrees of corrosion are obtained through accelerated corrosion testing. Subsequently, axial compression experiments are conducted to observe the impact of corrosion on the buckling behavior. Several parameters, including the diameter-to-thickness ratio, thickness, and corrosion rate, are considered. As the corrosion rate increases, the modulus of elasticity, yield strength, ultimate strength, and elongation at failure of Q345B steel decrease. The maximum geometric imperfection of corroded circular steel tubes (CST) shows a linear relationship with the corrosion rate, with all specimens of corroded CST buckling at the section with the maximum geometric imperfection. The thickness of uniform corrosion has a power relation with the corrosion rate of CST. The local buckling load and ultimate load of CST decrease by 28.6% and 26.4%, respectively, when the corrosion rate reaches 15.5%. Finite element analysis, validated by experimental results, is performed to analyze the buckling performance of corroded CST using the ABAQUS software. Current specifications slightly overestimate the local buckling load and ultimate load, as the effect of corrosion is not included. New modified models for predicting the local buckling load and ultimate load of corroded CST are developed based on current specifications, providing accurate predictions of the buckling behavior of corroded CST.