Experimental study and parameter sensitivity analysis of axial compression in locally corroded slender circular steel tubes

Abstract

Localized corrosion is a prevalent and critical damage mode in steel structures, significantly impacting their durability and load-carrying capacity. This study employs a localized electrochemical acceleration method to fabricate 15 specimens, conducting experiments and analysis on the axial compression behavior of locally corroded hollow circular steel tubes (LCHSTs). The research investigates the effects of slenderness ratio, corrosion rate, angle, height, and position on the performance of slender columns. Additionally, three-dimensional (3D) scanning was employed to gather statistical data on the corrosion morphology. The results indicate that localized corrosion alters the failure mode of the specimens from global buckling to local buckling, with the local buckling location corresponding to the corrosion position. Furthermore, localized corrosion diminished the load-carrying capacity and ductility of LCHST specimens by 22.94∼32.64 % and 11.06∼29.94 %, respectively. An inhomogeneous localized corrosion finite element model based on unit displacement was established and the reliability of the simulation method was validated. Parameter samples were obtained using Latin Hypercube Sampling (LHS), and the Extended Fourier Amplitude Sensitivity Test (eFAST) method was employed to assess the sensitivity of corrosion parameters, revealing significant interactions among them. The total-order index for corrosion rate was the highest at 0.45, while those for corrosion position and corrosion height were only 0.12 and 0.11, respectively. Through experimental results, the most existing standards were evaluated and analyzed, resulting in the development of an empirical fitting equation based on GB50017–2017, as well as a theoretical calculation formula for a modified stability coefficient that incorporates centroid shift. Both methods exhibited high simulation accuracy.