• 제목/요약/키워드: cable bridge

검색결과 748건 처리시간 0.026초

USN기반의 교량 모니터링 시스템 구현 (Implementation of A Bridge Monitoring System Based on Ubiquitous Sensor Networks)

  • 이성화;전민석;이안규;김진태
    • 한국인터넷방송통신학회논문지
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    • 제9권4호
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    • pp.1-8
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    • 2009

  • 본 연구 이전에 제안되었던 실시간 교량 모니터링 시스템은 교량 곳곳에 배치되어 있는 센서들로부터 중앙서버로 동축 케이블을 통해 데이터를 송수신하였는데, 동축 케이블을 이용하여 교량 전체의 센서들의 네트워크를 구성하기 위해서는 막대한 인력과 비용이 따르게 된다. 본 연구에서는 USN을 기반으로 한 교량 모니터링 시스템 제안하고, 이에 대한 프로토타입을 설계 및 구현하였다. HSDPA를 통해 얻은 센싱 데이터 값을 TCP/IP 소켓을 통해 교량 모니터링 서버에 전달함으로써 양방향 통신을 구축하여 그래프 변환을 하는 전체 시스템을 구현하였다.

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Damage detection of bridges based on spectral sub-band features and hybrid modeling of PCA and KPCA methods

  • Bisheh, Hossein Babajanian;Amiri, Gholamreza Ghodrati
    • Structural Monitoring and Maintenance
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    • 제9권2호
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    • pp.179-200
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    • 2022

  • This paper proposes a data-driven methodology for online early damage identification under changing environmental conditions. The proposed method relies on two data analysis methods: feature-based method and hybrid principal component analysis (PCA) and kernel PCA to separate damage from environmental influences. First, spectral sub-band features, namely, spectral sub-band centroids (SSCs) and log spectral sub-band energies (LSSEs), are proposed as damage-sensitive features to extract damage information from measured structural responses. Second, hybrid modeling by integrating PCA and kernel PCA is performed on the spectral sub-band feature matrix for data normalization to extract both linear and nonlinear features for nonlinear procedure monitoring. After feature normalization, suppressing environmental effects, the control charts (Hotelling T2 and SPE statistics) is implemented to novelty detection and distinguish damage in structures. The hybrid PCA-KPCA technique is compared to KPCA by applying support vector machine (SVM) to evaluate the effectiveness of its performance in detecting damage. The proposed method is verified through numerical and full-scale studies (a Bridge Health Monitoring (BHM) Benchmark Problem and a cable-stayed bridge in China). The results demonstrate that the proposed method can detect the structural damage accurately and reduce false alarms by suppressing the effects and interference of environmental variations.

  • https://doi.org/10.12989/smm.2022.9.2.179 인용 KSCI

Experimental and numerical studies on VIV characteristics of π-shaped composite deck of a cable-stayed bridge with 650 m main span

  • Wei Lei;Qi Wang;Haili Liao;Chengkai Shao
    • Wind and Structures
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    • 제38권2호
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    • pp.93-107
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    • 2024

  • A π-shaped composite deck in the form of an open section is a type of blunt body that is highly susceptible to wind loads. To investigate its vortex-induced vibration (VIV) performance, a large-scale (1/20) section model of a cable-stayed bridge with a main span of 650 m was tested in a wind tunnel. The vibration suppression mechanism of the countermeasures was analyzed using computational fluid dynamic. Experimental results demonstrate that the vertical and torsional VIVs of the original section can be suppressed by combining guide plates with a tilt angle of 35° and bottom central stabilizing plates as aerodynamic countermeasures. Numerical results indicate that the large-scale vortex under the deck separates into smaller vortices, resulting in the disappearance of the von Kármán vortex street in the wake zone because the countermeasures effectively suppress the VIVs. Furthermore, a full-bridge aeroelastic model with a scale of 1/100 was constructed and tested to evaluate the wind resistance performance and validate the effectiveness of the proposed countermeasures.

  • https://doi.org/10.12989/was.2024.38.2.093 인용