Structural Performance of a Four-Span Warren Truss Bridge with a Damaged Member under Vertical Loading

Steel Warren truss bridges are widely used in medium-span applications due to their efficient axial-force-based load transfer mechanism. However, during service life, individual members may lose part of their load-carrying capacity due to corrosion, fatigue cracking, or accidental damage, which can alter global stiffness and force redistribution. This study investigates the structural performance of a four-span Warren steel truss bridge under a concentrated vertical load considering the presence of a single damaged member. A two-dimensional finite element model is developed in Abaqus, where truss members are modeled using axial elements and the damaged condition is simulated by reducing (or eliminating) the stiffness contribution of a selected member. The structural response is evaluated in terms of vertical displacement patterns and Von Mises stress distribution to identify critical regions and assess the bridge’s ability to redistribute loads after damage. The results indicate that introducing a damaged member leads to noticeable changes in displacement demand and localized stress amplification in adjacent diagonal members and joints, highlighting the key role of load-path redundancy in Warren configurations. The findings provide practical insight for damage-sensitive assessment, inspection prioritization, and reliability-oriented evaluation of multi-span Warren truss bridges subjected to vertical loading.

کلیدواژه ها:

Warren steel truss bridge ، axial elements ، load-path