Structural Performance of a Four-Span Warren Truss Bridge with Dual Damaged Members under Combined Horizontal and Vertical Loading

This study investigates the structural performance of a four-span Warren steel truss bridge with dual damaged members under combined horizontal and vertical loading conditions. Structural damage in truss members can significantly alter load transfer mechanisms, increase stress concentrations, and reduce the overall stiffness of the bridge system. To evaluate these effects, a two-dimensional finite element model of the truss bridge was developed in Abaqus. Two members within the structure were assumed to be damaged and modeled through stiffness reduction to simulate deterioration or partial failure. A combined loading condition consisting of a ۲۰۰ kN vertical load and a ۲۰۰ kN horizontal load was applied to represent realistic service conditions where bridges are subjected to multiple simultaneous forces such as traffic loads, wind, or seismic effects. The numerical results reveal that the presence of two damaged members leads to a more pronounced redistribution of internal forces, resulting in increased stress concentrations in adjacent members and amplified structural deformations compared with single-member damage scenarios. The interaction between horizontal and vertical loads further intensifies these effects, influencing both axial force distribution and overall structural response. Despite the localized stiffness reduction, the truss structure maintains its global stability due to its inherent redundancy and alternative load paths. The findings highlight the importance of evaluating multiple-member damage scenarios under combined loading conditions for a more reliable assessment of truss bridge safety and structural robustness.

کلیدواژه ها:

Warren steel truss bridge ، internal forces ، horizontal and vertical loads