Influence of random pit corrosion on axial stiffness of thin-walled circular tubes

Thin-walled circular tubes have been widely used in space lattice structures and other industrial areas. Corrosion is inevitable for steel tubes in terms of service life, and it will considerably reduce the axial stiffness and change the mechanical behavior of the entire structure. The present work aims to investigate the axial stiffness of corroded circular steel tubes (CSTs) subjected to compression force. Initial and elastoplastic stiffness values were investigated, and an analytical formula was proposed. The influence of corrosion thickness tc and material strength fy on the residual moment capacity of CSTs was also investigated. The proposed analytical formula can accurately predict the axial stiffness of CSTs with random pitting corrosion.