Full‐Life‐Cycle Fatigue Vulnerability of Prefabricated Segmental Concrete Bridges Considering Corrosion–Fatigue Coupling Using a Joint Damage Index Method

Prefabricated segmental bridges are widely adopted for accelerated bridge construction due to their minimal traffic disruption and environmental impact. However, segmental joints are vulnerabilities over time. Single‐indicator fatigue assessments fail to capture synergistic degradation effects. This study proposes a joint damage index method integrating corrosion‐induced prestress loss and concrete deterioration for a full‐life‐cycle framework. A refined finite element model, validated against experimental data, reveals that joint concrete compressive stress exceeds segmental stress by 9.8%, whereas joint prestressing tendons show a 10% stress increase after 100 years, approaching ultimate strength. Mid‐span joints demonstrate significantly higher fatigue failure probabilities than adjacent segments. Compared with conventional first‐ and second‐order reliability methods, the proposed joint damage index method yields vulnerability estimates that better reflect actual system behavior, with prediction errors constrained within 12%. providing a robust theoretical basis for the long‐term durability design of prefabricated segmental bridges.