Optimal Sensor Placement For Bridge Structural Health Monitoring Based On Intelligence Algorithm

In recent years, with the rapid development of bridge structure, bridge structural health monitoring (BSHM) has become a hotspot research at home and abroad. Configuring sensors reasonably is the premise to guarantee the quality of BSHM, it is crucial to acquire bridge structural health information accurately in real-time and to achieve bridge monitoring and estimating. Effective Independence method (EFI) and other traditional optimization algorithms have been applied in the problem of Optimal Sensor Placement (OSP) for bridge structures, but these algorithms have their limitations. The research of OSP for bridge structures based on intelligence optimization algorithms is just at the early stage. With the development of intelligence optimization algorithms, such as Genetic Algorithm (GA), and so on, intelligence optimization algorithms are utilized in many fields successfully, the applications provide a theoretical basis for the OSP for bridge structures.Some new methods based on Immune Algorithm (IA), Artificial Fish School Algorithm (AFSA), Memetic algorithm and Chaotic Monkey Algorithm (CMA) are proposed to solve the problem of OSP for bridge structures in the thesis. Utilize these intelligence optimization algorithms to find the best positions and quantities that acquire data about bridge structures more accurate with minimum sensors. Finally, taking two bridges as example to verify the effectiveness of these optimization algorithms to achieve OSP for different types of bridge structures, the results indicate that the proposed intelligence optimization algorithms can achieve OSP of bridge structures better.The contents of this thesis are follows:(1) On the basis of the BSHM, analyzing the problem of OSP for bridge structures, then the mathematic is established. The finite element models (FEMs) of bridge structures are built by the software Ansys, modal analysis are carried out, and the modal vibration are extracted to access to the Modal Assurance Criterion (MAC) matrix.(2) Aiming at the problem of OSP for BSHM, IA and AFSA are applied to the OSP for an arch bridge. In order to verify the effectiveness of IA and AFSA in the OSP for the bridge, compared with GA and PSO, respectively, the results show better convergence and higher accuracy.(3) To study the application of OSP for bridge structures based on Memetic algorithm and CMA, taking an suspension bridge as a bridge structure model. Adding local search strategy in GA forms Memetic algorithm, the OSP for bridge structures based on Memetic algorithm can get better results compared with PSO. At the same time, the chaos theory is introduced in the Monkey Algorithm (MA), a method based on CMA is proposed. The results indicate CMA can better solve the problem of OSP for bridge structures, and in comparison with MA, CMA has obvious advantages.