Experimental study on natural frequency measurement of underwater structure with fiber optic sensor

2nd International Symposium on Application of Materials Science and Energy Materials

材料科学;能源学

Yang, Jingnan^1^2 ; He, Xiongjun^1 ; Xu, Jingjing^1

School of Transportation, Wuhan University of Technology, Wuhan, China^1

Department of Civil and Materials Engineering, University of Illinois at Chicago, Chicago, United States^2

关键词: Dynamic strain;    FBG sensor;    Fiber Bragg Grating Sensors;    Fourier transformations;    Free vibration;    Frequency measurements;    Initial displacements;    Water depth;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/490/3/032001/pdf
DOI  :  10.1088/1757-899X/490/3/032001

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

An equivalent single pier model of a typical deep water bridge was investigated in this study. A rod made of aluminum was used to simulate a bridge pier and a mass was attached to the top of the rod to simulate the superstructure of the bridge. An initial displacement of 5cm was applied to the top of the rod and then released to produce free vibration. Fiber Bragg grating (FBG) sensor was used to measure the dynamic strain of the rod under different water depth conditions. The feasibility of fiber optic sensor applied in underwater structures monitoring is discussed. The natural frequency of the underwater structure can be obtained by Fourier transformation of the dynamic strain. The experimental results show that the FBG sensor can realize the measurement of dynamic strain and natural frequencies of underwater structures under different water depths.