Quantitative Evaluation and Micromechanical/Elastodynamic Analysis of Nonlinear Ultrasonic Properties of Contacting and Weak Interfaces

接触界面和弱界面非线性超声特性的定量评估和微机械/弹性动力学分析

基本信息

批准号：
18560079
负责人：
BIWA Shiro
金额：
$ 2.39万
依托单位：
Kyoto University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2006
资助国家：
日本
起止时间：
2006 至 2007
项目状态：
已结题

项目摘要

This research has been carried out to make a quantitative evaluation of nonlinear ultrasonic characteristics of contacting/weak-bonding interfaces as well as to give a sound theoretical explanation to them by micromechanical and elastodynamic analyses, thereby to contribute to the establishment of nonlinear ultrasonic characterization or monitoring method for these interfaces. First, the perturbation analysis of harmonic generation due to nonlinear ultrasonic effect has been reformulated in a more rigorous way based on a nonlinear interface model, and the relation between the nonlinear pressure-gap relation and the second harmonic amplitude has been clarified. Second, based on the vibration velocity measurement using a laser-Doppler vibrometer, a method has been established which converts the voltage output of a piezoelectric transducer to the displacement amplitude, as well as corrects for the frequency dependence of the transducer's sensitivity. This has enabled a quantitative experi … More mental evaluation of harmonic generation characteristics at contacting interface, and a quantitative comparison between the experimental data and the theoretical prediction. Third, the frequency dependence of the interfacial stiffnesses obtained from the bulk and interface wave measurements has been discussed in the light of spatial inhomogeneity of local stiffness as well as the viscous loss at the interface. Finally, a preliminary study has been carried out for nonlinear Lamb wave propagation characteristics along a plate under partial contact conditions, by measuring the higher harmonics in the velocity waveforms of the Lamb wave in a plate under different contact pressures. As a result, the generation of the third harmonics has been found to be a remarkable feature in this experiment. These findings are considered to be meaningful in the view of establishing a new characterization method for imperfect interfaces based on nonlinear ultrasonic characteristics of not only bulk waves but also guided waves such as Rayleigh or Lamb waves. Less

已经进行了这项研究，以对接触/弱键入界面的非线性超声特征进行定量评估，并通过微力机械和弹性动力学分析对它们提供明智的理论解释，从而有助于建立这些接口的非线性超声特征或监测这些接口的方法。首先，基于非线性界面模型的更严格的方式对谐波产生的谐波产生分析进行了重新重新制定，并且已经阐明了非线性压力间隙关系与第二个谐波放大器之间的关系。其次，基于使用激光多普勒振动的振动速度测量，已经建立了一种方法，该方法将压电传感器的电压输出转换为位移放大器，并正确依赖传感器敏感性的频率依赖性。这使得能够进行定量体验……对接触界面时谐波产生特征的心理评估以及实验数据与理论预测之间的定量比较。第三，根据局部刚度的空间不均匀性以及界面处的粘性损失，已经讨论了从整体和界面波测量获得的界面刚度的频率依赖性。最后，通过测量不同接触压力下板板波的速度波形中的较高谐波，在部分接触条件下沿板的非线性羔羊波传播特性进行了初步研究。结果，已经发现第三个谐波的产生是该实验的非凡特征。这些发现被认为是有意义的，它是基于基于散装波的非线性超声特征的不完美界面的新表征方法，而且还具有引导波，例如雷利（Rayleigh）或羊肉波。较少的