288 0

초음파 비선형 파라미터 절대측정기술

Title
초음파 비선형 파라미터 절대측정기술
Other Titles
Absolute Measurement Technique of Ultrasonic Nonlinear Parameter
Author
송동기
Alternative Author(s)
Dong-Gi Song
Advisor(s)
장경영
Issue Date
2016-08
Publisher
한양대학교
Degree
Master
Abstract
The nonlinear ultrasonic technique is a promising method that can evaluate microstructural defects such as thermal aging, fatigue and creep. In the nonlinear ultrasonic technique, the ultrasonic nonlinear parameter is measured as an evaluation indicator, which is determined by absolute displacement amplitudes of fundamental and harmonic components. However, it is difficult to measure the displacement amplitudes of the harmonic components because they are very small. Therefore, the piezoelectric detection method has been developed, which converts the detected electrical signal amplitude into the absolute displacement amplitude by through a calibration process to measure the ultrasonic nonlinear parameter. In this study, the proper window function and scaling factors were presented, and a guideline of the measurement system construction was proposed. In order to verify the proposed idea, two measurement processes were conducted: 1) increasing input power with fixed propagation distance and 2) increasing propagation distance with fixed input power. Two measurement results were similar each other and also were closely related with the reference. In conclusion, the proposed methods are useful for the absolute ultrasonic nonlinear parameter measurement.
URI
https://repository.hanyang.ac.kr/handle/20.500.11754/125442http://hanyang.dcollection.net/common/orgView/200000487142
Appears in Collections:
GRADUATE SCHOOL[S](대학원) > MECHANICAL CONVERGENCE ENGINEERING(융합기계공학과) > Theses (Master)
Files in This Item:
There are no files associated with this item.
Export
RIS (EndNote)
XLS (Excel)
XML


qrcode

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

BROWSE