Evaluation of atmospheric corrosion damage to steel space structures in coastal areas

Steel space structures in coastal areas, often exposed in the open air, are inevitably subjected to atmospheric corrosion. This paper presents a framework for evaluation of potential damage due to atmospheric corrosion to steel space structures in coastal areas through an integration of knowledge in material science and structural analysis. An empirical model for estimating corrosion of steel material is first presented based on long-term experimental data available. Equations relating structural natural frequency sensitivity to structural member thickness are then derived in consideration of both inner and outer surface corrosions of the structural member. The nonlinear static analysis is finally conducted to evaluate effects of atmospheric corrosion on the stress of structural members and the safety of steel space structures. By taking a real large steel space structure built in southern coastal area in China as example, the feasibility of the proposed approach is examined and the potential damage caused by atmospheric corrosion to the structure is assessed. The results demonstrate that the atmospheric corrosion does not obviously affect the natural frequencies of the structure but it does create stress redistribution and some of the structural members may have large stress changes.