Abstract:In order to study the fatigue crack extension characteristics in the longitudinal rib-roof welding position of orthotropic steel bridge decks, taking a steel box beam cable-stayed bridge as an engineering background, based on the linear elasticity fracture mechanics and extended finite element method, a longitudinal rib-roof three-dimensional crack extension model is established through ABAQUS software. A semi-elliptic initial crack is introduced to analyze the stress intensity factors at the crack tip of weld root and weld toe. The results show that under the action of vehicle load, the fatigue cracks of longitudinal rib-roof connection details are the I-II-III compound cracks mainly by I-crack. When the cracks are laterally located just below the wheels and longitudinally between the axles, the fatigue crack extension trend is the greatest. When a vehicle passes within 2 m near the cracks, the stress intensity factor fluctuates between the maximum values and has the larger influence on the crack extension.
