Non-destructive evaluation of isotropic plate structures by means of mode filtering in the frequency-wavenumber domain
Non-destructive evaluation of isotropic plate structures by means of mode filtering in the frequency-wavenumber domain
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DOI：
10.1016/j.ymssp.2020.106801
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发表时间：
2020-08-01
影响因子：
8.4
通讯作者：
Pullin，Rhys
中科院分区：
文献类型：
--
作者：
Purcell，Frederick A. F.;Eaton，Mark;Pullin，Rhys
摘要无损检测技术广泛应用于航空航天、绿色能源和汽车等行业。这些技术，包括超声波，尽管使用了，但在速度和分辨率方面仍然存在局限性。本文提出了一种用于各向同性材料损伤检测的频率波数域带通模式滤波技术。使用带有压电换能器的三维扫描激光多普勒测振仪(SLDV)在时间和空间域捕获数据，用从75 kHz到400 khz的各种稳态信号和从75 khz到400 khz的调频信号来激励结构。根据A0兰姆波模式的频率和波长绘制了厚度图。该技术在两个尺寸为400 mm×400 mm的铝试件上进行了演示，厚度范围为0.5 mm至8 mm，具有明显的几何特征。通过多频激励和基于模式的滤波相结合的方法，实现了厚度的估计，平均厚度百分比误差为15%。在最大板厚为8 mm时，直径为10 mm的圆形厚度减小清晰可见。这项技术被证明比波数滤波性能更好，因为它允许将来自多频率稳态激励的数据组合成单一的结果厚度图。这一改进在厚度较大的情况下尤为重要。
Abstract Non-Destructive Testing (NDT) techniques are prevalent in the aerospace, green energy and automotive industries. These techniques, including ultrasound, despite their use, still have limitations surrounding speed and resolution. This work presents the development of a band-pass mode filtering technique in the frequency wavenumber domain for the purpose of damage detection in isotropic materials. Data was captured in the temporal and spatial domain using a 3D Scanning Laser Doppler Vibrometer (SLDV) with piezoelectric transducers exciting the structure with a variety of steady state signals ranging in frequency from 75 kHz to 400 kHz and a frequency modulated signal from 75 kHz to 400 kHz. A thickness map was created based on the frequency and wavelength of the A 0 Lamb wave mode. The technique was demonstrated on two aluminium specimens with dimensions of 400 mm by 400 mm with a thickness range of 0.5 mm to 8 mm with distinct geometric features. Through using multi-frequency excitation combined with mode based filters an estimation of thickness was achieved with a mean percentage thickness error of 15%. Circular thickness reductions with a diameter of 10 mm were clearly identified at the maximum plate thickness of 8 mm. This technique was shown to perform better than wavenumber filtering by allowing data from multi frequency steady state excitation to be combined into a single resulting thickness map. This improvement was shown to be particularly important at greater thicknesses.