A Framework for Long-Term Vibration-Based Monitoring of Bridges

Area of Science:

• Structural Engineering
• Civil Engineering
• Vibration Analysis

Background:

• Vibration-based structural health monitoring (SHM) faces challenges with measurement uncertainties and low sensitivity to early-stage damage.
• Existing damage indicators often struggle to detect subtle structural degradation.

Purpose of the Study:

• To develop a robust framework for long-term bridge monitoring that overcomes limitations in current SHM techniques.
• To improve the sensitivity and reliability of damage detection and localization in bridges.

Main Methods:

• Utilized three vibration-based damage indicators: modal curvature, modal strain energy, and modal flexibility.
• Developed a novel long-term monitoring parameter: the frequency of damage indicators exceeding a threshold.
• Simulated various damage levels on an 84-m railway bridge for numerical analysis.

Main Results:

• The proposed framework successfully detects and locates damage from very low levels upwards.
• The new parameter, especially with modal strain energy, clearly visualizes damage initiation and progression.
• Damage localization was accurate across all simulated damage levels and high noise conditions.

Conclusions:

• The developed framework significantly enhances the capability of vibration-based SHM for long-term bridge monitoring.
• The new parameter offers a reliable method for early damage detection and continuous assessment of bridge integrity.
• The approach is resilient to noise, making it practical for real-world applications.