Impedance-based Long-term Structural Health Monitoring for Tidal Current Power Plant Structure in Noisy Environments

doi:2011.25.4.59

J. Ocean Eng. Technol. > Volume 25(4); 2011 > Article

J. Ocean Eng. Technol. 2011;25(4):59-65.
DOI: https://doi.org/10.5574/KSOE.2011.25.4.059

Min Ji-Young,Shim Hyo-Jin,Yun Chung-Bang,Yi Jin-Hak

Civil and Environmental Engineering KAlST,Civil and Environmental Engineering KAlST,Civil and Environmental Engineering KAlST,Coastal Engineering and Ocean Energy Research Department KORDI

잡음 환경 하에서의 전기-역학적 임피던스 기반 조류발전 구조물의 장기 건전성 모니터링

민지영,심효진,윤정방,이진학

한국과학기술원 건설 및 환경공학과,한국과학기술원 건설 및 환경공학과,한국과학기술원 건설 및 환경공학과,한국해양연구원 연안개발에너지연구부

Keywords: Piezoelectric sensors, Electro-mechanical impedance, Long-term structural health monitoring, Noisy environment, Principal component analysis

핵심용어: 압전센서, 전기-역학적 임피던스, 장기 구조물 건전성 모니터링, 잡음 환경, 주성분 분석

Abstract

In structural health monitoring (SHM) using electro-mechanical impedance signatures, it is a critical issue for extremely large structures to extract the best damage diagnosis results, while minimizing unknown environmental effects, including temperature, humidity, and acoustic vibration. If the impedance signatures fluctuate because of these factors, these fluctuations should be eliminated because they might hide the characteristics of the host structural damages. This paper presents a long-term SHM technique under an unknown noisy environment for tidal current power plant structures. The obtained impedance signatures contained significant variations during the measurements, especially in the audio frequency range. To eliminate these variations, a continuous principal component analysis was applied, and the results were compared with the conventional approach using the RMSD (Root Mean Square Deviation) and CC (Cross-correlation Coefficient) damage indices. Finally, it was found that this approach could be effectively used for long-term SHM in noisy environments.