Scattering from Partially Closed Cracks and other Imperfect Interfaces

本研究的目的是研究超声波如何 从部分闭合的裂缝和其他不完善的 接口。 这项研究的一个重要部分是开发一个 考虑表面粗糙度的界面模型 以及裂纹或粘结面之间的部分接触。 一个同样 一个重要的部分是建立一个测量过程的模型 解释了发射和接收的特性 的传感器。 这项研究的结果将使更多的 关于这些裂缝和界面的完整的定量信息 从散射的超声信号中提取。 的实例 这种定量信息包括疲劳裂纹的尺寸 以及扩散结合强度的估计。 等 信息使人们能够定量地评估质量， 制造零件的可靠性。 采用的方法是 互动 它涉及分析和数值的结合 这些方法的结果将不断进行比较。 此外，委员会认为， 从这些计算中得到的预测将持续 与现有数据相比， 爱荷华州州立大学非破坏性评估中心。

The objective of this research is to study how ultrasonic waves scatter from partially closed cracks and other imperfect interfaces. An important part of this research is developing a model for such interfaces that takes account of surfaces roughness and the partial contact between crack or bond faces. An equally important part is developing a model of the measurement process that accounts for the transmitting and receiving characteristics of the transducers. The results of this research will enable more complete, quantitative information about such cracks and interfaces to be extracted from scattered ultrasonic signals. Examples of such quantitative information include the size of a fatigue crack and an estimate of the strength of a diffusion bond. Such information enables one to assess quantitatively the quality and reliability of manufactured parts. The approach used is interactive. It involves a combination of analytical and numerical approaches whose outcomes will be continuously compared. Moreover, the predictions from these calculations will be continuously compared with existing data from measurements carried out at the Center for Nondestructive Evaluation at Iowa State University.