Jin J, Quek S T, Wang Q
Department of Civil Engineering, National University of Singapore, SE 117576, Singapore.
Ultrasonics. 2005 May;43(6):481-93. doi: 10.1016/j.ultras.2004.09.005.
Interdigital transducers (IDT) for non-destructive evaluation (NDE) of cracks in plates are designed based on an analytical model established previously. Key considerations include mode selectivity, excitation strength, collimation of wave and cost. The advantage of mode selectivity of IDT over PZT patch is presented both analytically and experimentally. Effects of parameters, namely finger spacing, width, length, number of fingers, and the size of IDT, on the excitation strength and mode selectivity are considered. This led to the design of a mobile double-sided IDT as an efficient device where excitation strength is strong and focused. The device was fabricated in-house using commercially available piezoelectric ceramics and used to develop a procedure for accurate identification of the direction and extent of cracks in plates. Three aluminum plates, one with a linear deep crack, another with a piecewise linear shallower crack and the third with a curved crack, were used to illustrate the accuracy and efficiency of both the proposed device and procedure for effective NDE.
基于先前建立的分析模型，设计了用于板材裂纹无损检测（NDE）的叉指换能器（IDT）。关键考虑因素包括模式选择性、激励强度、波的准直和成本。通过分析和实验展示了IDT相对于PZT贴片在模式选择性方面的优势。考虑了诸如指间距、宽度、长度、指数量以及IDT尺寸等参数对激励强度和模式选择性的影响。这促成了一种移动双面IDT的设计，它是一种高效的设备，激励强度大且聚焦。该设备是使用市售压电陶瓷在内部制造的，并用于开发一种准确识别板材裂纹方向和范围的程序。使用了三块铝板，一块带有线性深裂纹，另一块带有分段线性较浅裂纹，第三块带有弯曲裂纹，以说明所提出的设备和有效无损检测程序的准确性和效率。
