Noncontact modal excitation of a classical guitar using ultrasound radiation force
Noncontact modal excitation of a classical guitar using ultrasound radiation force
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使用超声辐射力对古典吉他进行非接触模态激励
DOI：
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
J. Helps
中科院分区：
文献类型：
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作者：
T. M. Huber;N. Beaver;J. Helps
先前的研究表明，可以利用空气中的超声辐射力对各种尺寸的物体进行模态激励，从数百微米长的微悬臂梁到硬盘驱动器悬架和其他几厘米长的悬臂梁。目前的研究表明，超声辐射力激励技术也可用于较大物体（在本例中为原声吉他）的模态激励。事实证明，超声波辐射力激励和扫描振动计的非接触式组合可以测量 Cordoba 45R 古典吉他在 70 至 800 Hz 范围内的频率响应和操作偏转形状。共振频率和偏转形状与使用传统机械振动台测量的相似。通过使用一对超声波换能器并调整它们的相对相位差，可以选择性地增强或抑制不同的共振。这是对之前研究的实质性扩展，因为吉他比之前使用的设备大了几个数量级。
Previous studies have demonstrated that it is possible to use the ultrasound radiation force in air for modal excitation of objects ranging in size from microcantilevers that are a few hundred microns in length to hard drive suspensions and other cantilevers a few centimeters long. The current study demonstrates that the ultrasound radiation force excitation technique can also be used for modal excitation of significantly larger objects, in this case an acoustic guitar. It was demonstrated that the noncontact combination of ultrasound radiation force excitation and a scanning vibrometer allowed measurements of both the frequency response and operating deflection shapes of a Cordoba 45R classical guitar in the range from 70 to 800 Hz. The resonance frequencies and deflection shapes are similar to those measured using a conventional mechanical shaker. By using a pair of ultrasound transducers and adjusting their relative phase difference, it was possible to selectively enhance or suppress different resonances. This is a substantial extension over previous studies because the guitar is several orders of magnitude larger than devices used previously.