Comparative Structural Behavior Analysis of a Four-Span Parker Truss Bridge with a Single Damaged Member under Horizontal Loads

This study examines the structural response of a four-span Parker truss bridge with a single damaged member subjected to horizontal loading. The Parker truss configuration, characterized by its variable-depth geometry, provides improved stiffness and optimized axial load distribution compared to constant-depth truss systems. To evaluate the influence of localized damage on lateral performance, a finite element model of the bridge was developed using beam elements with rigid joints to accurately represent global structural behavior. Damage was introduced by reducing the stiffness of a selected diagonal member, simulating deterioration resulting from corrosion, fatigue, or previous overloads. A horizontal load was applied at a critical node to replicate lateral actions such as wind forces or vehicular impact. The numerical results reveal that the presence of a damaged member significantly alters the lateral load path, leading to increased von Mises stress concentrations in adjacent members and amplified horizontal displacements. Compared to the intact configuration, the damaged system demonstrates reduced lateral stiffness and a more pronounced deformation profile, especially near the region of compromised integrity. These findings highlight the sensitivity of Parker truss bridges to localized damage under horizontal loading and underscore the need for targeted inspection strategies and timely maintenance to preserve structural safety. The results contribute to a deeper understanding of how member deterioration influences lateral behavior in variable-depth truss systems, offering valuable insights for structural assessment and future bridge design improvements.

کلیدواژه ها:

Parker truss bridge ، Truss Degradation ، Stress Redistribution