An Analysis of the Dynamic Behavior of Damaged Reinforced Concrete Bridges under Moving Vehicle Loads by Using the Moving Mesh Technique

This work proposes a numerical investigation on the effects of damage on the structural response of Reinforced Concrete (RC) bridge structures commonly adopted in highway and railway networks. An effective three-dimensional FE-based numerical model is developed to analyze the bridge’s structural response under several damage scenarios, including the effects of moving vehicle loads. In particular, the longitudinal and transversal beams are modeled through solid finite elements, while horizontal slabs are made of shell elements. Damage phenomena are also incorporated in the numerical model according to a smeared approach consistent with Continuum Damage Mechanics (CDM). In such a context, the proposed method utilizes an advanced and efficient computational strategy for reproducing Vehicle-Bridge Interaction (VBI) effects based on a moving mesh technique consistent with the Arbitrary Lagrangian-Eulerian (ALE) formulation. The proposed model adopts a moving mesh interface for tracing the positions of the contact points between the vehicle’s wheels and the bridge slabs. Such modeling strategy avoids using extremely refined discretization for structural members, thus drastically reducing computational efforts. Vibrational analyses in terms of damage scenarios are presented to verify how the presence of damage affects the natural frequencies of the structural system. In addition, a comprehensive investigation regarding the response of the bridge under moving vehicles is developed, also providing results in terms of Dynamic Amplification Factor (DAFs) for typical design bridge variables.