Critical Review of Non-Destructive Testing Techniques for Structural Health Monitoring in Civil Infrastructure

Structural Health Monitoring (SHM) is essential for maintaining the safety and serviceability of civil infrastructure. Traditional visual inspection, although widely used, is subjective and often inadequate for detecting hidden or early-stage damage, creating a gap that requires more reliable approaches. This study conducts a critical review of major Non-Destructive Testing (NDT) techniques, including ultrasonic testing, acoustic emission, infrared thermography, radiography, digital image correlation, and fiber optic sensors, with an emphasis on their applications in bridges, dams, tunnels, and wind turbines. The review follows a structured methodology that categorizes infrastructures, analyzes the principles, strengths, and limitations of each NDT method, and evaluates integrated or hybrid approaches. The findings demonstrate that no single technique provides a comprehensive assessment; however, combining methods significantly enhances diagnostic accuracy and reliability. Emerging technologies, including robotics, UAVs, computer vision, artificial intelligence, and digital twin frameworks, are identified as transformative tools that enable automation, predictive modeling, and real-time monitoring. Overall, the study concludes that the integration of conventional NDT with intelligent technologies represents the most promising pathway for scalable and cost-effective SHM, supporting safer and more sustainable infrastructure management.

کلیدواژه ها:

Structural Health Monitoring ، Non-Destructive Testing ، Visual Inspection ، Hybrid Methods ، Digital Twin ، Civil Infrastructure