High-speed noncontact acoustic inspection method for civil engineering structure using multitone burst wave
High-speed noncontact acoustic inspection method for civil engineering structure using multitone burst wave
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DOI：
10.7567/jjap.56.07jc10
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发表时间：
2017-07-01
影响因子：
1.5
通讯作者：
Katakura, Kageyoshi
中科院分区：
文献类型：
--
作者：
Sugimoto, Tsuneyoshi;Sugimoto, Kazuko;Katakura, Kageyoshi
非接触式声学检测方法关注于共振现象，并且目标表面通过与空气传播的声音一起振动来测量。可以从远距离检测混凝土结构表层附近的内部缺陷。然而，它需要相当长的测量时间来获得信噪比（S/N），只是为了找到一些谐振频率。在我们的方法中，使用常规波形“单音突发波”，仅一个频率用于一个声波发射，以在安全的低功率下使用激光多普勒振动计（LDV）实现高S/N比（例如，He-Ne lmW）。另一方面，根据激光和声波之间的传播速度的差异，可以用于高速测量的波形被设计为使用用于一个声波发射的多个频率（“多音突发波”）。当使用该波形时，在35个测量点处的测量时间从210秒显著减少到28秒。因此，7.5倍的高速测量成为可能。通过一些演示实验，我们证实了我们的测量技术的有效性。(C)2017日本应用物理学会
The noncontact acoustic inspection method focuses on the resonance phenomenon, and the target surface is measured by being vibrated with an airborne sound. It is possible to detect internal defects near the surface layer of a concrete structure from a long distance. However, it requires a fairly long measurement time to achieve the signal-to-noise (S/N) ratio just to find some resonance frequencies. In our method using the conventional waveform "single-tone burst wave", only one frequency was used for one-sound-wave emission to achieve a high S/N ratio using a laser Doppler vibrometer (LDV) at a safe low power (e.g., He-Ne 1 mW). On the other hand, in terms of the difference in propagation velocity between laser light and sound waves, the waveform that can be used for high-speed measurement was devised using plural frequencies for one-sound-wave emission ("multitone burst wave"). The measurement time at 35 measurement points has been dramatically decreased from 210 to 28 s when using this waveform. Accordingly, 7.5-fold high-speed measurement became possible. By some demonstration experiments, we confirmed the effectiveness of our measurement technique. (C) 2017 The Japan Society of Applied Physics