• Computational Structural Engineering
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• v.16 no.1
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• pp.7-14
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• 2003

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.1
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• pp.165-174
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• 2010

In this paper, a two-phase structural health monitoring system using acceleration response signatures are presented to firstly alarm the change in structural condition and to secondly detect the changed location for full-scale concrete girder bridges. Firstly, Mihocheon Bridge which is a two-span continuous concrete girder bridge is selected as the target structure. The dynamic response features of Mihocheon Bridge are extracted by forced vibration test using bowling ball. Secondly, the damage alarming occurrence and the damage localization techniques are selected to design two-phase structural health monitoring system for Mihocheon Bridge. As the damage alarming techniques, auto-regressive model using time-domain signatures, correlation coefficient of frequency response function and frequency response ratio assurance criterion are selected. As the damage localization technique, modal strain energy-based damage index method is selected. Finally, the feasibility of two-phase structural health monitoring systems is evaluated from static loading tests using a dump truck.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.36 no.1
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• pp.49-56
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• 2023

With the development of technology worldwide, bridges are becoming larger, and the number of old bridges is also rapidly increasing. Monitoring the structural health of large, aging bridges is essential to preventing large-scale accidents. In this study, the application of a LoRa low-power wide-area network (LPWAN)-based wireless measurement system was investigated, and a LoRa wireless measurement system was established in the cable-stayed bridge section of Cheonsa Bridge, located in Shinan-gun, Jeollanam-do, Korea. The applicability of the LoRa LPWAN-based wireless monitoring system to large marine bridges was reviewed by comparing the performance and economic feasibility with wire-based monitoring systems that were built and operated by establishing a measurement system for the pylons, cables, and reinforcing girders of the bridge.

• Magazine of the Korea Institute for Structural Maintenance and Inspection
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• v.20 no.2
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• pp.14-17
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• 2016

• Magazine of the Korea Institute for Structural Maintenance and Inspection
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• v.18 no.4
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• pp.83-88
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• 2014

구조물에 최적화된 센서 배열(Sensor Array)을 수행하는 것은 센서 네트워크 설계에서 중요한 요소이다. 그러나 센서의 설치와 관리는 구조물이 처해 있는 환경이나, 경제성 그리고 센서의 주파수대역의 제한과 같은 다양한 원인으로 인해 매우 어려울 수 있다. 이 논문에서는 일반적인 문제와 환경에서 현재 사용되고 있는 물리적 센서 대용으로 가상 시각 센서(VVS: Virtual Visual Sensor)를 제안하였다. 가상 시각 센서는 설치가 간편하고 경제적이며 관리가 편하다는 큰 장점을 가지고 있다. 이러한 가상 시각 센서의 기본적인 아이디어는 최첨단 컴퓨터 시각 알고리즘과 마커 추출 기법의 적용으로 이루어진다. 이 연구에서는 가상 시각 센서를 이용하여 모드 형태와 주파수를 추출하는데 용이하다는 점을 보여주며 이를 구조물 건전성 모니터링에 적용할 경우 효율적이라는 점을 입증하였다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.5A
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• pp.421-431
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• 2009

This paper is the study on the verification of structural health monitoring (SHM) algorithm based on the ultrasonic guided wave. An active inspection system using Lamb wave (LW) for SHM was considered. The basic study about the application of this algorithm was performed for detecting the circular notch defect in steel plate. LW testing technique, pitch-catch method, was used for interpretation of circular notch defect with depth of 50% of plate thickness and 7 mm width. Damage characterization takes place by comparing $S_0$ mode sensor signals collected before and after the damage event. By subtracting the signals of both conditions from each other, a scatter signal is produced which can be used for damage localization. The continuous Gabor wavelet transform is used to attain the time between the arrivals of the scatter and sensor signals. A new practical damage monitoring algorithm, based on damage monitoring polygon and pitch-catch method, has been proposed and verified with good accuracy. The possible damage location can be estimated by the average on calculated location points and the damage extent by the standard deviation.

• Journal of the Korea Society for Simulation
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• v.19 no.2
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• pp.147-155
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• 2010

It often occur to nature disaster that like earthquake, typhoon, etc. around KOREA. A Haiti and Chile also metropolitan area of KOREA occur earthquake. in result, People consider nature disaster. Structures of present age are easily affected by nature disaster. So we are important that warn of dangerous situation as soon as possible. On this study, I introduce Integrated Health Monitoring System for Infra-structure. I develop Structure Health Monitoring System on web-site. Administrator always monitor structure on real-time using internet network. As Administrator using mobile device like PDA, Administrator always monitor structure. As using this system, Damage of nature disaster is minimized and is prevented post damage.

• Journal of KSNVE
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• v.26 no.3
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• pp.3-8
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• 2016

• Journal of KSNVE
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• v.18 no.5
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• pp.20-29
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• 2008

• Electrical & Electronic Materials
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• v.32 no.3
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• pp.24-31
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• 2019