Abstract：Very high cycle fatigue (VHCF) has emerged as a critical scientific challenge in the domains of structural integrity and operational safety, characterized by fracture and failure behaviors fundamentally distinct from conventional fatigue mechanisms. This paper systematically reviews the mechanisms of crack initiation and propagation in metallic materials under VHCF loading, and, grounded in thermodynamic principles of condensed matter physics, elucidates the intrinsic coupling among fatigue fracture, energy dissipation, and thermal response. Building on this theoretical framework, recent advances in the application of infrared thermography to fatigue research are comprehensively assessed, encompassing fatigue limit prediction, crack detection and monitoring, quantitative evaluation of internal cracks, and life assessment. The review underscores the unique advantages of thermally informed approaches at both theoretical and experimental levels, providing new perspectives for efficient fatigue life prediction. Finally, drawing on the latest research progress, prospective directions for advancing infrared thermography in fatigue studies are outlined. Overall, this work establishes a systematic research paradigm for thermal approaches in VHCF, offering both deeper insights into its thermodynamic essence and a foundation for broader engineering applications.
2025, Vol. 46 
