固体粗糙界面与超声的非线性相互作用研究

Nonlinear interaction between ultrasound and solid rough interface

本文提出了一种随机弹性接触界面与超声的非线性相互作用理论.首先建立了描述随机弹性接触界面的模型,然后分别研究了界面间应力-应变关系在线性简化模型、指数模型、高斯模型下与超声的非线性相互作用.数值仿真和实验研究结果均表明高斯模型更适合描述固体接触界面.本文在介观结构上解释了固体界面与超声的相互作用,对工业超声无损检测裂缝、缺陷及损伤有指导意义.

The interaction of ultrasound with an interface between two rough surfaces in contact has become a quite popular topic in many areas related to non-destructive evaluation （NDE）. We proposed a theory of ultrasonic nonlinear interaction between some random rough elastic interfaces. The model of random elastic-contact interface is first described, and then the nonlinear ultrasonic interaction of interfaces with stress-strain relationship is studied, by using different models including linear simplified model, exponential model, and Gaussian model. Results of numerical simulations and experiments demonstrate that the Gaussian model is more suitable for describing the solid rough interfaces. This study provides an explanation of the ultrasonic interaction on mesoscopic level, which is a theoretical basis for practical application to detect cracks, defects and injuries in industrial ultrasonic NDE.