Active acoustic damage detection of structural cavities using internal acoustic excitations
Active acoustic damage detection of structural cavities using internal acoustic excitations
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DOI：
10.1177/1475921719835761
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发表时间：
2020-01-01
影响因子：
6.6
通讯作者：
Niezrecki, Christopher
中科院分区：
文献类型：
--
作者：
Beale, Christopher;Inalpolat, Murat;Niezrecki, Christopher
研究了一种新的结构损伤检测方法，该方法依赖于结构空腔边界声透射率变化的可探测性。该方法侧重于主动损伤检测，利用在暴露于内部声激励下测量结构腔外的声压响应。主动损伤检测概念首先在一个4米高的风力涡轮机叶片上进行了演示，使用声波束成形技术来证实，与未受损表面相比，通过受损表面传播的声能在损伤局部增加。这一概念得到了进一步的验证，仅考虑从距离46米的风力涡轮机叶片不同距离的有限麦克风测量的声压响应。考虑到各种损坏类型、严重程度和位置，在公用事业规模的叶片上开发并执行了全面的测试活动。数据分析使用光谱分析和基于统计的指标相结合，以检测和跟踪损坏的进展，并确定测试变量的趋势。总的来说，在大多数情况下，从结构外部测量的压力响应中观察到功率谱密度的大幅增加。光谱差异随着损伤程度的增加而增加，从距离损伤位置17.1 m的多个传感器可以很容易地检测到5.1 cm长的损伤。使用简单的信号处理算法和初步测试配置，在叶片中长度之前就可以很容易地检测到损坏。在这项工作中获得的数据是对该方法在复杂结构上的能力的初步调查，并为未来研究信号处理技术和测试配置铺平了道路，这些技术和测试配置将提高主动声损伤检测方法的性能。
A novel structural damage detection methodology that relies on the detectability of the changes in acoustic transmissibility across boundaries of structural cavities is investigated. The approach focuses on active damage detection by leveraging the acoustic pressure responses measured external to structural cavities while exposed to internal acoustic excitations. The active damage detection concept is first demonstrated on a 4 m wind turbine blade using acoustic beamforming techniques to confirm that the acoustic energy transmitted through a damaged surface increases local to the damage compared to an undamaged surface. The concept is further verified, only considering acoustic pressure responses measured from limited microphones positioned at various distances from a 46 m wind turbine blade. A comprehensive testing campaign is developed and executed on the utility-scale blade considering various damage types, severity levels, and locations. The data are analyzed using a combination of spectral analysis and statistics-based metrics to detect and track the progression of damage as well as identify trends across the test variables. Overall, large increases in the power spectral density were observed from the pressure responses measured external to the structure in most cases. The spectral differences increased as the damage became more severe and damage as small as 5.1 cm in length was easily detected from multiple sensors up to 17.1 m from the damage location. Damage was easily detected when implemented before the mid-length of the blade using simple signal processing algorithms and preliminary test configurations. The data acquired in this work serve as a preliminary investigation into the capability of the approach on complex structures and paves the path for future research into the signal processing techniques and test configurations that will enhance the performance of the active acoustic damage detection approach.