부산대학교 도서관

Non-destructive testing (NDT) techniques have been employed in all kinds of fields successfully for many years. Newly developed and applied NDT methods of detecting and monitoring fatigue crack in metal material are reviewed in this paper. Some methods based on machine vision technique and image recognition techniques are introduced for at or near surface visible crack testing. As a newborn offspring of acoustic emission technique, electromagnetically induced acoustic emission methods also introduced for both visible and invisible fatigue cracks on metal structure. Nonlinear ultrasonic method and some other NDT methods presently available are mentioned, too. The principles, applied testing fields, data processing algorithms, advantages and disadvantages of these methods are discussed.