Broken wires diagnosis method numerical simulation based on smart cable structure

Abstract

The smart cable with embedded distributed fiber optical Bragg grating (FBG) sensors was chosen as the object to study a new diagnosis method about broken wires of the bridge cable. The diagnosis strategy based on cable force and stress distribution state of steel wires was put forward. By establishing the bridge-cable and cable-steel wires model, the broken wires sample database was simulated numerically. A method of the characterization cable state pattern which can both represent the degree and location of broken wires inside a cable was put forward. The training and predicting results of the sample database by the back propagation (BP) neural network showed that the proposed broken wires diagnosis method was feasible and expanded the broken wires diagnosis research area by using the smart cable which was used to be only representing cable force.

Keywords

Fiber optical Bragg grating sensor / bridge cable / broken wires diagnosis / smart cable / BP neural network

References

[1] Zhang J, Wang W. Manual of bridge inspection and reinforcement, 2007, Beijing: China Communication Press

[2] Ye J. Discussion on fracture of steel wires for cable. Steel Construction, 2003, 18(65): 35-36.

[3] Wu X, Wang J, Yang S. Development of a testing system for detecting the defect in diagnoal bridge cable. Mechanical Science and Technology, 2001, 20(6): 901-903.

[4] Wu X, Kang Yi, Chen H. Nondestructive testing method and technique for cable-stayed bridge steel cables. Key Engineering Materials, 2004, 270–273(7): 1493-1499.

[5] Cooper M. Radiographic examination of wire ropes suspension cables. Materials Evaluation, 1992, 50(12): 1383-1384.

[6] S. Li, D. Jiang, and X. Zhao, “Desensitized encapsulation FBG sensor for smart cable in bridge,” in 22nd International Conference on Optical Fiber Sensors (OFS22), Beijing, China, October 15–19, 2012.

[7] S. Li and D. Jiang, “Structural large strain monitoring based on FBG sensor,” in Symposium on Photonics and Optoelectronics (SOPO2009), Wuhan, China, August 14–16, 2009.

[8] Jiang D, Li S, Liu L, Liu S, Zhang E, Zhao X. Fiber optical Bragg grating strain sensor for smart cable, 2010

[9] Li S, Zhou M. Long-term mechanical properties of smart cable based on FBG desensitized encapsulation sensors. Photonic Sensors, 2014, 4(3): 236-241.

[10] Zhang Q, Li Q, Tang L. Study on structural damage location identification by damage indices for cable-stayed bridges. Engineering Mechanics, 2008, 25(5): 163-169.

[11] Ministry of construction of the People’s Republic of China Technical code of maintenance for city bridge CJJ99-2003, 2003, Beijing: China Architecture & Building Press