Fatigue crack propagation simulation of orthotropic bridge deck based on extended finite element method

Orthotropic Steel Decks (OSDs) are widely used in various types of steel bridges due to its benefits of light weight, high load bearing capacity and speedy construction. However, fatigue remains as the predominant problem for OSDs. Many researchers have investigated fatigue issues of welded joints through experiments but is not a cost-effective solution. Therefore, it is necessary to combine experimental data with numerical approaches. Fracture mechanics approach has already shown its reliability and can be used to model and analyze fatigue crack propagation. In this paper, a numerical simulation is performed to predict the fatigue crack propagation using extended finite element method (XFEM). Two numerical models were considered namely CT-specimen and OSD, to evaluate the modelling efficiency. To verify the simulation, the results were compared with the experimental data. In predicting the fatigue crack propagation rate using two-dimensional CT-specimen, numerical results provided a good agreement with a maximum difference of 0.03% in the slope (m) and 1.48% in the intercept (C) of the power law equation. Furthermore, a simulation was performed on three-dimensional OSD structure to predict the fatigue crack growth.