Bioinspired Low-Frequency Material Characterisation
Bioinspired Low-Frequency Material Characterisation
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仿生低频材料表征
DOI：
10.1155/2012/927903
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发表时间：
2012
影响因子：
--
通讯作者：
M. Lovell
中科院分区：
文献类型：
--
作者：
C. Hopper;S. Assous;P. Wilkinson;D. Gunn;P. Jackson;J. Rees;R. O’Leary;M. Lovell
新编码的信号由高灵敏度宽带传感器在 40-200kHz 范围内传输，可以对聚丙烯、聚氯乙烯和黄铜样品进行亚波长材料辨别和厚度测定。频域频谱可以同时测量材料特性，包括纵向声速和衰减常数以及厚度测量。实验室测试测量结果与模型结果吻合良好，声速预测误差小于 1%，厚度辨别力至少为波长/15。过去只能通过利用更高频率的方法来匹配这些测量的分辨率。使用低频获得相同分辨率的能力具有许多优点，特别是在处理高衰减材料时。这种方法与过去使用实际或模拟动物信号的仿生方法有很大不同，因此具有在需要提高穿透力和高分辨率的一系列领域应用的潜力，例如无损检测和评估、地球物理学和医学物理学。
New-coded signals, transmitted by high-sensitivity broadband transducers in the 40–200 kHz range, allow subwavelength material discrimination and thickness determination of polypropylene, polyvinylchloride, and brass samples. Frequency domain spectra enable simultaneous measurement of material properties including longitudinal sound velocity and the attenuation constant as well as thickness measurements. Laboratory test measurements agree well with model results, with sound velocity prediction errors of less than 1%, and thickness discrimination of at least wavelength/15. The resolution of these measurements has only been matched in the past through methods that utilise higher frequencies. The ability to obtain the same resolution using low frequencies has many advantages, particularly when dealing with highly attenuating materials. This approach differs significantly from past biomimetic approaches where actual or simulated animal signals have been used and consequently has the potential for application in a range of fields where both improved penetration and high resolution are required, such as nondestructive testing and evaluation, geophysics, and medical physics.