Influence of guided ultrasonic wave scattering directionality on the detection sensitivity for SHM of fatigue cracks
Influence of guided ultrasonic wave scattering directionality on the detection sensitivity for SHM of fatigue cracks
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DOI：
10.1117/12.848621
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发表时间：
2010-03
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影响因子：
--
通讯作者：
P. Fromme
中科院分区：
文献类型：
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作者：
P. Fromme
局部和分布式引导超声波阵列系统为长期监测大型结构的结构完整性提供了一种有效的方法。已证明使用永久连接的传感器阵列适用于检测模拟腐蚀损坏。然而，疲劳裂纹的检测灵敏度取决于裂纹相对于换能器元件的位置和方向，并且对于某些换能器位置，即使对于重大缺陷也不会检测到信号变化。裂纹状缺陷具有散射场的方向性图案，该方向性图案取决于入射波相对于缺陷的角度、缺陷深度以及特征缺陷尺寸与波长的比率。 A0 兰姆波模式的散射场的方向性图案是通过 3D 有限元模拟预测的，并通过使用激光干涉仪对加工的部分贯穿和全厚度凹口进行的实验测量进行验证。找到了良好的一致性，并且可以准确地预测方向性模式。这些结果为使用导波传感器量化板结构缺陷的检测灵敏度提供了基础。
Localized and distributed guided ultrasonic waves array systems offer an efficient way for the long-term monitoring of the structural integrity for large structures. The use of permanently attached sensor arrays has been shown to be applicable to detect simulated corrosion damage. However, the detection sensitivity for fatigue cracks depends on the location and orientation of the crack relative to the transducer elements, and for some transducer locations no change in the signal even for a significant defect will be detected. Crack-like defects have a directionality pattern of the scattered field depending on the angle of the incident wave relative to the defect, the defect depth, and the ratio of the characteristic defect size to wavelength. The directionality pattern of the scattered field for the A0 Lamb wave mode is predicted from 3D Finite Element simulations and verified from experimental measurements at machined part-through and through-thickness notches using a laser interferometer. Good agreement is found and the directionality pattern can be predicted accurately. These results provide the basis for the quantification of the detection sensitivity for defects in plate structures using guided wave sensors.