A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Vision-Based Vibration Measurement of Stay-Cables by Video Motion Magnification and Dynamic Mode Decomposition
Routine inspection of stay cable of cable-stayed bridges is essential to ensure structural performance and integrity. Currently, there are three types of inspection or measurement systems: static-direct inspection using loadcell, magnetic-based permeability measurement, and vibration measurement. The vibration measurement is widely employed because of its efficacy and practicality. The current vibration measurements of stay cables include contact type such as accelerometers and non-contact type such as laser Doppler vibrometer. However, they have numerous limitations such as: requirement for physical access and limited spatial information in the case of contact accelerometers, and expensive and laborious choice in using laser vibrometer. The recent advancement in computer vision has benefited researchers in exploring a middle path of using video measurements to extract meaningful displacement information. A single video data can be used to obtain displacement at any desired location of the target structure which in the other methods would either require to mount at multiple locations or conducting repetitive tests. In this paper the cable vibration is captured by video camera and the Phase-based Video Motion Magnification method is implemented to magnify the cable micro-vibration. The modal parameters of the cable such as natural frequencies, mode shapes and damping ratios are extracted from the time-history data which are obtained by analyzing the video data and Discrete Centroid Searching Method by applying Dynamic Mode Decomposition. At first, the method is experimentally verified on cable specimen and then extended to a full-scale cable-stayed bridge application, a pedestrian cable-stayed bridge in Tokyo. The results from video data are compared with Laser Doppler Vibrometer which was simultaneously used to record the cable vibration. The close agreement in the results of experiments and full-scale test demonstrate the efficacy of the proposed method in extracting modal parameters useful for condition assessment of the cables in a cable-stayed bridge.
Vision-Based Vibration Measurement of Stay-Cables by Video Motion Magnification and Dynamic Mode Decomposition
Routine inspection of stay cable of cable-stayed bridges is essential to ensure structural performance and integrity. Currently, there are three types of inspection or measurement systems: static-direct inspection using loadcell, magnetic-based permeability measurement, and vibration measurement. The vibration measurement is widely employed because of its efficacy and practicality. The current vibration measurements of stay cables include contact type such as accelerometers and non-contact type such as laser Doppler vibrometer. However, they have numerous limitations such as: requirement for physical access and limited spatial information in the case of contact accelerometers, and expensive and laborious choice in using laser vibrometer. The recent advancement in computer vision has benefited researchers in exploring a middle path of using video measurements to extract meaningful displacement information. A single video data can be used to obtain displacement at any desired location of the target structure which in the other methods would either require to mount at multiple locations or conducting repetitive tests. In this paper the cable vibration is captured by video camera and the Phase-based Video Motion Magnification method is implemented to magnify the cable micro-vibration. The modal parameters of the cable such as natural frequencies, mode shapes and damping ratios are extracted from the time-history data which are obtained by analyzing the video data and Discrete Centroid Searching Method by applying Dynamic Mode Decomposition. At first, the method is experimentally verified on cable specimen and then extended to a full-scale cable-stayed bridge application, a pedestrian cable-stayed bridge in Tokyo. The results from video data are compared with Laser Doppler Vibrometer which was simultaneously used to record the cable vibration. The close agreement in the results of experiments and full-scale test demonstrate the efficacy of the proposed method in extracting modal parameters useful for condition assessment of the cables in a cable-stayed bridge.
Vision-Based Vibration Measurement of Stay-Cables by Video Motion Magnification and Dynamic Mode Decomposition
Lecture Notes in Civil Engineering
Wu, Zhishen (editor) / Nagayama, Tomonori (editor) / Dang, Ji (editor) / Astroza, Rodrigo (editor) / Wangchuk, Samten (author) / Siringoringo, Dionysius M. (author) / Fujino, Yozo (author)
Experimental Vibration Analysis for Civil Engineering Structures ; Chapter: 14 ; 149-162
2022-08-24
14 pages
Article/Chapter (Book)
Electronic Resource
English
| British Library Online Contents | 2018
Vibration Control of Stay Cables
| British Library Conference Proceedings | 1999