公开(公告)号：US09772315B2

公开(公告)日：2017-09-26

申请号：US14787127

申请日：2013-12-23

Applicant: KOREA ADVANCED INSTITUTE OF SCIENCE AND TECHNOLOGY

Inventor： Hoon Sohn ,  Hyung Jin Lim ,  Su Young Yang ,  Peipei Liu

IPC: G01N29/04 ,  G01N29/06 ,  G01N29/24 ,  G01N29/28 ,  G01B17/04 ,  G01M5/00 ,  G01N29/34 ,  G01N29/46

CPC classification number: G01N29/46 ,  G01B17/04 ,  G01M5/0033 ,  G01M5/0066 ,  G01N29/045 ,  G01N29/0654 ,  G01N29/2437 ,  G01N29/28 ,  G01N29/348 ,  G01N2291/01 ,  G01N2291/023 ,  G01N2291/02475 ,  G01N2291/02491 ,  G01N2291/0258 ,  G01N2291/0289 ,  G01N2291/106

Abstract: The present invention relates to a safety diagnosis method for a structure using a nonlinear ultrasonic wave modulation technique. The safety diagnosis method includes: making the structure vibrate by applying signals of different ultrasonic frequencies; converting the responses of the structure generated by the vibration into digital signals; extracting first modulation signals by subtracting the harmonic responses and the linear responses of the signals of different ultrasonic frequencies from the digital signals and synchronously demodulating the digital signals; constructing a first sideband spectrogram by combining the first modulation signals generated by continuously changing at least frequency among the signals of different ultrasonic frequencies; and deciding whether the structure is cracked based on the first sideband spectrogram. Even though the power of the ultrasonic wave applied to the structure is very small as compared with the related art, whether there is the damage is precisely decided, and thus power consumption may be reduced.