Impact resistance and damage evaluation of corroded circular steel tubes

Circular steel tubes with corrosion defects are prone to causing catastrophic consequences under impact force. Therefore, a series of extended finite element analysis (FEA) models of corroded circular steel tubes were established based on experimental results from preliminary work to reveal the failure mechanism and damage assessment method of circular steel tubes with corrosion defects under lateral impact. The failure modes, impact force-time history curves, and displacement curves of corroded steel tubes were obtained and analyzed. It can be concluded that the corrosion zone of the steel tube absorbs most of the energy during the impact process and expands the scope of the local depression zone after the impact on the upper surface of the steel tube, but the local corrosion defects have little influence on the overall damage mode of the steel tube specimen. The peak value of impact force increases with the increase of initial velocity. The increase of the corrosion zone depth-to-steel tube wall thickness ratio (C_d) and the steel tube diameter-to-thickness ratio (D/T) both reduce the peak value of impact force and increase the deformation of the plastic dent zone after impact. By incorporating the corrosion parameters C_L and C_d, a modified equation for the length of the plastic dent zone, considering the effects of corrosion defects, is proposed. Furthermore, a simplified calculation equation for assessing the lateral impact damage of circular steel tubes with corrosion defects was developed and validated against experimental data, demonstrating its reliability. This research holds significant theoretical and engineering value for the design of corrosion and collision prevention measures, as well as residual life assessment studies in architectural tubular structures, bridges, pipeline engineering, and offshore platform structures.