钢筋腐蚀电化学损伤的分数微分与元胞自动机识别方法-结构工程专业论文.docxVIP

哈尔滨 哈尔滨工业大学工学硕士论文 - - II - Abstract Reinforced concrete (RC) structure is one of the most important structural styles at present and in the long future. Corrosion of the reinforcing steel is the major factor which deteriorates the durability of RC structrues。The electrochemical essence determines that the corrosion monitoring online could be achieved effectively and directly based on electrochemical. To realize the corrosion monitoring based on electrochemical theory ultimately, some key scientific problems in the recognition methods of the electrochemical corrosion characteristics should be broken through previously. Specifically, integrated and fast identification approach of the general corrosion features where dispersion and diffusion effects are considered in the equivalent circuit (EC) should be established, and the quantitative prediction of the growth and evolution of the pitting based on the electrochemical noise (EN) intrinsic information should be explored. From the structural health monitoring (SHM) perspective, the author deploys the research to resolve the key scientific issues mentioned above for the on-line electrochemical corrosion monitoring of RC structures. The conjunction of theory investigation, numerical simulation and experimental verification had been applied here. Firstly, the algorithm for the response in time domain of the transfer function of electrochemical corrosion system has been established based on the complex variable function approximation. Then the influence of the series elements in the complex EC on the response in the time domain with the transient potentiostatic step excitation has been investigated. Secondly, Fractional Derivative (FD) theory had been applied to establish the integrated and fast identification approach to recognize the electrochemical characteristics of the complex EC containing dispersion and diffusion elements in time domain. Then, the FD algorithm has been verified numerically based on the resu