A Modal Analysis of Violin with Nearfield Acoustical Holography.

用近场声全息技术对小提琴进行模态分析。

• 批准号: 07650469
• 负责人: NAGAI Keinosuke
• 金额: $ 1.22万
• 依托单位: UNIVERSITY OF TSUKUBA
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07650469/
• 关键词: eigen mode; eigen frequency; acoustical holography; nearfield; vibration analysis; quadrature detection; Chladni method; violin; 周期検波; クラドニ法; 音響ホログラフィ法; データ収集; 振動面の再構成; 非接触計測法; サイドロープ; 縮尺実験

We have developed a method using nearfield acoustical holography to measure velocity of a surface from the acoustic data radiated from it. We examined at first the parameters of the data acquisition by the numerical simulation and the experiment in the reduced size with high frequency to reconstruct properly the vibrating surface. They are the position of the plane, data acquisition region and the sampling intervals. Then using the results we have experimentally measured the vibration of a violin top plate. It is shaken by a vibration-tool and the radiated pressure field is measured on a plane near the plate. The velocity of the plate are reconstructed from the data, of which the nodal lines are almost the same of those once obtained by Chladni method. This means that our method is reliable. The resolution of the method is less than a hundredth of the wave length, because the about 7 mm width of the 'f-hole' of the plate could be reconstructed in the 'ring mode' of 335 Hz, of which wavelength is more than 1 m. These results will be presented at International Symposium on Simulation, Visualization and Auralization for Acoustic Research and Education (ASVA'97).

我们开发了一种利用近场声学全息术从表面辐射的声学数据测量表面速度的方法。我们首先通过数值模拟和实验对数据采集参数进行了检查，在缩小尺寸的高频条件下，适当地重建了振动表面。它们是平面位置、数据采集区域和采样间隔。然后利用所得结果对小提琴顶板的振动进行了实验测量。用振动仪对其进行震动，并在靠近板块的平面上测量辐射压力场。利用这些数据重建了板块的速度，其节点线与Chladni法得到的节点线基本一致。这意味着我们的方法是可靠的。该方法的分辨率小于波长的百分之一，因为在335 Hz的“环模式”下，可以重建约7 mm宽的板的“f孔”，其中波长大于1 m。这些结果将在声学研究和教育的模拟、可视化和听觉化国际研讨会（ASVA' 1997）上发表。

项目成果

K,Nagai et al: "Measurement of Vibrating Violin Surfaces by Acoustical Holographic Method" Proceedings of International Symposium on Simulation, Visualization and Auralization for Acoustic Research and Education. (in Press).

K,Nagai 等人：“声学全息法测量振动小提琴表面”声学研究和教育模拟、可视化和可听化国际研讨会论文集。

K.Nagai et al: "Measurement of Vibrating Violin Surfaces by Acoustical Holographic Method" Proceedings of International Symposium on Simulation Visualization and Auralization for Acoustic Research and Education. (in Press).

K.Nagai 等人：“声学全息法测量振动小提琴表面”声学研究和教育模拟可视化和可听化国际研讨会论文集。

K.Nagai et al.: "Measurement of Vibrating Violin Surfaces by Acoustical Holographic Method21GC01:Proceedings of International Symposium on Simulation,Visualization and Auralization for Acoustic Research and Education" (in press).

K.Nagai 等人：“用声学全息方法测量振动小提琴表面21GC01：声学研究和教育模拟、可视化和可听化国际研讨会论文集”（正在出版）。