Nondestructive testing methods for rail defects detection

The rapid progress in the construction of heavy-haul and high-speed railways has led to a surge in rail defects and unforeseen failures. Addressing this issue necessitates the implementation of more sophisticated rail inspection methods, specifically involving real-time, precise detection, and assessment of rail defects. Current applications fail to address the evolving requirements, prompting the need for advancements. This paper provides a summary of various types of rail defects and outlines both traditional and innovative non-destructive inspection techniques, examining their fundamental features, benefits, drawbacks, and practical suitability for railway track inspection. It also explores potential enhancements to equipment and software. The comprehensive review draws upon pertinent international research and review papers. Furthermore, the paper introduces a fusion of inspection methods aimed at enhancing the overall reliability of defect detection. • Rail defects are classified by location as internal (from manufacturing or service) or surface (from wear and fatigue). • NDT methods for rail defect detection fall into two main types: visual testing and physical inspection. • Visual testing uses image processing to segment rail images and extract defect-related data. • Physical inspection (UT, MFL, ECT, ACFM, AET) uses signal processing to analyze rail conditions. • An integrated approach uses multiple sensors and data analysis for fast, thorough rail inspection and maintenance planning.