A Review of Ultrasonic Testing and Evaluation Methods with Applications in Civil NDT/E

New construction or existing structures are tested for material quality as well as damage and defects during their life cycle. Advancements in data science and sensor technologies have significantly improved Non-Destructive Testing (NDT) for monitoring the health of civil structures. This review covers 82 recent studies on ultrasonic testing (UT) methods used in civil NDT/E. It explains basic ultrasound principles, new developments in signal and image processing, and evaluates key imaging techniques like Synthetic Aperture Focusing Technique (SAFT), Total Focusing Method (TFM), and Computed Tomography (CT) for identifying defects and assessing materials. The review also discusses the use of advanced signal processing methods to better characterize defects and enhance image quality. Emerging trends include the use of machine learning for automatically identifying defects, new sensor technologies for real-time monitoring, and integrated monitoring systems using Internet of Things (IoT) and edge computing. Applications in material evaluation and testing structural components such as bridges and buildings are also examined. The review highlights challenges like handling large amounts of data, ensuring efficient computations, and creating standardized testing protocols. Future research directions aim to make UT methods more accurate, reliable, and scalable, contributing to the safety and durability of civil infrastructure. This review provides valuable information for researchers, engineers, and industry professionals on the latest developments, current challenges, and future opportunities in ultrasonic-based civil infrastructure NDT/E.