Title: Nonlinear ultrasonic NDE techniques for micro-damages detection in solid media

Speaker: LI Weibin

From: Pusan National University, Korea

Time: 10:00 a.m., Jan. 28, 2013

Place: Multifunctional Hall of DSP Building

Welcome!

Sponsors:

Science and Technology Department

Ultrasonic Physics and Exploration Laboratory

 

Abstract of the report:

One of the important applications of ultrasonic waves is nondestructive evaluation(NDE), conventional ultrasonic NDE is based on measuring linear acoustic parameters such as wave velocity, attenuation, to determine the elastic properties or defects in material.However, most conventional linear ultrasonic NDE technologies are very sensitive to gross defects, but much less sensitive for micro-damages detection, and early stage NDE has been one of the most demanding techniques in industries. Owning to highly sensitive to material micro-structural change, the nonlinear ultrasonic wave NDE has been recently taken as the most promising approach to meet this purpose. In this talk, firstly, the physical understanding of nonlinear ultrasonic wave and the nonlinearity sources in solid are analyzed, as well as a nondestructive approach to evaluate the heat treatment effect on Inconel X-750 alloy by using nonlinear ultrasonic waves. Secondly, nonlinear guided wave techniques is reported, the applications of nonlinear guided wave in composite structures is studied for quantifying micro-defects.