BK21 School for Creative Engineering Design of Next Generation Mechanical and Aerospace Systems, School of Mechanical and Aerospace Engineering, Seoul National University, Seoul, Republic of Korea.
IEEE Trans Ultrason Ferroelectr Freq Control. 2011 Dec;58(12):2689-98. doi: 10.1109/TUFFC.2011.2131.
The lowest-branch torsional guided wave is very effective in pipe damage inspection because of its non-dispersive characteristics, but it cannot be used for the simultaneous identification of axial and circumferential locations of a defect in a pipe. Motivated by recent developments in magnetostrictive transducer technology, which is especially efficient in torsional and shear wave generation, the goal of this investigation is to extend this technology for simultaneous identification of the axial and circumferential locations of cracks by using shear horizontal (SH) waves. Unlike the conventional magnetostrictive patch method using a single complete patch wound around the pipe's circumference, the proposed method segments the patch into several pieces to generate SH waves propagating over the pipe surface. Accordingly, SH waves in a pipe are generated and sensed individually by a meander coil placed separately on each segment. By using two sets of segmented-patch arrays separated by some distance, the cylindrical surface of a pipe can be inspected both axially and circumferentially. After the underlying angular profile of the patch segment is investigated, experiments identifying the axial and circumferential locations of multiple cracks in a pipe are carried out to demonstrate the potential of the proposed methodology.
最低阶扭转导波由于其无频散特性，在管道损伤检测中非常有效，但它不能用于同时识别管道中缺陷的轴向和周向位置。受磁致伸缩换能器技术最新发展的启发，该技术在扭转和剪切波的产生方面特别有效，本研究的目的是扩展该技术，通过使用水平剪切（SH）波来同时识别裂纹的轴向和周向位置。与使用单个完整贴片环绕管道周长的传统磁致伸缩贴片方法不同，所提出的方法将贴片分段，以生成在管道表面传播的 SH 波。相应地，通过分别放置在每个段上的蜿蜒线圈单独产生和感测管道中的 SH 波。通过使用两组通过一定距离分隔的分段贴片阵列，可以同时对管道的轴向和周向进行检查。在研究了贴片段的基本角度轮廓之后，进行了在管道中多个裂纹的轴向和周向位置识别实验，以证明所提出方法的潜力。
