서지주요정보
신경회로망과 웨이블릿 변환을 이용한 스마트 복합적층판의 충격 모니터링 연구 = Impact monitoring of smart composite laminates using neural networks and wavelet analysis
서명 / 저자 신경회로망과 웨이블릿 변환을 이용한 스마트 복합적층판의 충격 모니터링 연구 = Impact monitoring of smart composite laminates using neural networks and wavelet analysis / 성대운.
저자명 성대운 ; Sung, Dae-Un
발행사항 [대전 : 한국과학기술원, 2001].
Online Access 원문보기 원문인쇄

소장정보

등록번호

8012261

소장위치/청구기호

학술문화관(문화관) 보존서고

DAE 01004

SMS전송

도서상태

이용가능

대출가능

반납예정일

초록정보

Low-velocity impact damage is a major concern in the design of structures made of advanced laminated composites, because such damage is mostly hidden inside the laminates and cannot be detected by visual inspection. It is necessary to develop the impact monitoring techniques providing on-line diagnostics of smart composite structures susceptible to impacts. In this paper, I proposed the process for impact location detection in which the generated acoustic signals are detected by PZT using the neural network paradigms. To improve the accuracy and reliability of neural network based impact identification method, the Levenberg-Marquardt algorithm and the generalization methods were applied. This study concentrates not only on the determination of the location of impacts from sensor data, but also the implementation of time-frequency analyses such as the Wavelet Transform (WT) to measure the characteristics of acoustic emission (AE) signals for the determination of the occurrence and the severity of impact damages. These two processes can be operated simultaneously. As a fundamental approach, the characteristics of the AE signals due to matrix cracks and the evolution of free-edge delamination in $[\pm45_2/0_2/90_2]_S$ Gr/Ep laminates under tensile load were analyzed by the WT. The waveform based AE method was discussed to investigate the damage mode and mechanism. Then, the drop-weight type impact test was carried out to investigate the characteristics of impact damages of quasi-isotropic laminates using the WT. This paper shows that the AE signals generated by each damage mode can be distinguished by the WT. The examples of the simultaneous impact monitoring were presented. The cross-ply laminates and I-stiffened quasi-isotropic plate were tested to identify the impact location and the damages for the case of damaging impact loads.

서지기타정보

서지기타정보
청구기호 {DAE 01004
형태사항 xiii, 161 p. : 삽도 ; 26 cm
언어 한국어
일반주기 저자명의 영문표기 : Dae-Un Sung
지도교수의 한글표기 : 김천곤
지도교수의 영문표기 : Chun-Gon Kim
학위논문 학위논문(박사) - 한국과학기술원 : 항공우주공학전공,
서지주기 참고문헌 : p. 83-88
주제 충격
신경회로망
웨이블릿 변환
스마트 구조물
음향방출
Impact
Neural Network
Wavelet Analysis
Smart Structures
Acoustic Emission
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