線形及び非線形デジタル超音波計測による構造材料の非破壊特性評価

概要

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This study reviews recent progress in the non-destructive evaluation of structural materials and their damage using linear and non-linear ultrasonics. Rapid advances in digital signal acquisition and processing are fully utilized to extract ultrasonic features of sound velocity, velocity dispersion, attenuation, attenuation spectrum, and the second harmonic amplitude. The combination of these ultrasonic features with theories developed by physical acoustics provides a quantitative evaluation of characteristics and damage of structural materials. In particular, the effectiveness of non-linear ultrasonics is emphasized. The non-linear ultrasonic method using large incident wave amplitude measures dynamic response at minute cracks or voids. Moreover, this method does not depend on propagation distance, different from sound velocity and attenuation. This opens the possibility of a new non-destructive evaluation of initial structural damage such as fatigue, creep, stress corrosion, radiation damage, etc.
名古屋工業大学の論文
2004-03-31