Numerical analysis of fatigue performance of steel fiber reinforced concrete pavement based on microscopic crack growth theory
摘要
The fatigue performance of rigid pavements on steel bridge decks remains an underexplored area, with most existing research focusing on flexible pavement systems and simplified macroscopic models. This study presents a refined mesoscale numerical framework for analyzing fatigue crack propagation in steel fiber reinforced concrete (SFRC) pavements using fracture mechanics and the extended finite element method (XFEM). A three-dimensional local model of an SFRC-orthotropic steel deck system was developed, incorporating moving load simulations to determine critical stress locations. Parameters such as steel fiber volume content, yield strength, and aspect ratio were systematically varied to evaluate their effects on crack propagation behavior and fatigue life. Model predictions were validated against experimental fatigue test results, showing strong agreement in crack path and fatigue life estimates. The findings indicate that increasing steel fiber content from 0.5% to 2.0% progressively enhances fatigue resistance, with simulated fatigue life improvements of 51%, 28%, and 20% over the 0.5%-1.0%, 1.0%-1.5%, and 1.5%-2.0% intervals, respectively, while higher fiber strength and optimized aspect ratios further improve performance. The proposed methodology provides a reliable tool for optimizing SFRC pavement design and offers practical guidance for extending the fatigue life of steel bridge decks.