Numerical simulations for time-dependent corrosion surface of unpainted structural steel plates using spatio-temporal data

Abstract

Structural failure due to corrosion of steel members is a long-term process. A method to precisely simulate the development of corrosion on steel surfaces is of great significance. In this study, 9 specimens of unpainted steel plates, SM400A were used for the experiments. The experiments were conducted under artificial seawater corrosive environments to accelerate the corrosion process. The corrosion depth data of each unpainted steel plate for the spatial statistical analysis was measured by a laser focus measuring system when the accelerated corrosion experiments of 28, 84, and 168 days. Semivariogram was used in this spatial statistical analysis to research the spatial autocorrelation structures of the corrosion surface. By using this and the technique of ordinary kriging, the method to simulate the spatial features of corrosion surface was proposed. The results of the simulation indicated that the corrosion depth and surface topography of corrosion surfaces were highly consistent with the experiments. In addition, a prediction method for time-dependent corrosion surface was proposed by investigating the relationship between the spatial autocorrelation structures and their time-dependence data.