2011 Fiscal Year Final Research Report

Nonlinear Ultrasonic Spectroscopy for Closed Defects and Microscopic Damage by Amplitude-Modulated Waves

Research Project

Project/Area Number	22656029
Research Category	Grant-in-Aid for Challenging Exploratory Research
Allocation Type	Single-year Grants
Research Field	Materials/Mechanics of materials
Research Institution	Kyoto University
Principal Investigator	BIWA Shiro 京都大学, 大学院・工学研究科, 教授 (90273466)
Co-Investigator(Renkei-kenkyūsha)	MATSUMOTO Eiji 京都大学, 大学院・エネルギー科学研究科, 教授 (30093313)
Project Period (FY)	2010 – 2011
Keywords	非破壊評価 / 超音波 / 非線形特性 / 接触界面 / 複合材料
Research Abstract	Nonlinear ultrasonic characteristics of contacting interfaces and micro-damage for amplitude-modulated waves have been investigated. First, for the burst wave containing two frequency components, the transmitted wave through a contacting interface between metal blocks has been shown to contain the difference frequency component. Second, for amplitude-modulated waves propagating in a unidirectional carbon/carbon composite, the transmitted wave has been shown to change significantly accompanying low-frequency component generation. This phenomenon has been discussed based on the perturbation analysis of ultrasonic wave propagation in a nonlinear elastic medium. It is expected that these nonlinear low-frequency components can characterize defects and damage when the higher-harmonic measurements are difficult to perform.

(4 results)