サブハーモニック超音波フェーズドアレイによる閉じたき裂サイジング

英字タイトル:
Sizing of Closed Cracks Using Subharmonic Phased Array
著者:
小原良和 Yoshikazu OHARA 菅原あずさ Azusa SUGAWARA 山中一司 Kazushi YAMANAKA 三原毅 Tsuyoshi MIHARA
発刊日: 2016年8月 2日
公開日: 2019年6月19日

カテゴリ: 第13回

キーワードタグ:
closed cracksCrack depth sizingNondestructive testingPhased-array imagingSubharmonic waves

概要

Closed cracks can cause the underestimation or overlook by conventional (linear) ultrasonic method, because the ultrasound is transmitted through closed cracks. To solve this problem, we have developed an imaging method, subharmonic phased array for crack evaluation (SPACE), based on subharomonic generation by large-amplitude short-burst-wave input and phased-array imaging algorithm with frequency filtering. Thus far, we have demonstrated in the crack depth measurement in closed fatigue cracks and stress corrosion cracks (SCCs). In this study, some of the results we have obtained by SPACE are introduced as typical examples, where fundamental array (FA) images corresponding to the conventional linear ultrasonic images caused the underestimation of closed-crack depth, whereas subharmonic array (SA) images achieved the improvement in the accuracy of closed crack depth sizing.