Quantitative evaluation of fatigue damage accumulation and resultant crack initiation and propagation is one of the greatest concerns for plan life time management and license renewal in various industries. To develop a novel nondestructive evaluation method for fatigue damage evaluation, we applied Induced Current Focusing Potential Drop (ICFPD), which was developed for an inspection of defects, to processes of fatigue damage accumulation, small crack initiation and coalescence, and macroscopic crack growth. Measurements were performed on specimens fatigued under an axial strain controlled tension/compression load with various degrees of fatigue damage defined as a cycle ratio, N/Nc where Nc is a cycle giving maximum crack size of 3 mm at surface. ICFPD can be used to clearly detect and differentiate of these fatigue processes of damage accumulation without crack initiation and subsequent small crack initiation and macroscopic crack propagation.
|Number of pages
|Nihon Kikai Gakkai Ronbunshu, A Hen/Transactions of the Japan Society of Mechanical Engineers, Part A
|Published - 1997