Finite Element Simulation Research On Medium Scattering Of Open Boundary Microwave Field

There are two important research directions on the research of visualization and information processing technology for reinforced concrete structure, one direction is the design and manufacture of radars which are used for nondestructive testing of reinforced concrete structures, the other is the design of analysis software which is used for processing and imaging of the detected information. Analysis software consists mainly of two parts, the analysis of electromagnetic field simulation and the collection of information visualization. Two parts above are corresponding to the forward and inverse problems of electromagnetic numerical analysis in the calculation of electromagnetic fields. Electromagnetic field model is analyzed and the relevant data is obtained in the forward problem, imaging is finished in inverse problem via the data provided by forward problem. Therefore, research on forward problem is very necessary because it is the premise for the design of software and the theoretical support and data supply for inverse problem.After comparing the common methods on the issue of electromagnetic field numerical analysis in this paper, the finite element method (FEM) is selected as the basic method for the realization of forward problem analysis of electromagnetic field. In the process of using finite element method for numerical calculation of electromagnetic fields, the regional of two-dimensional electromagnetic field model is set so as to achieve the mesh generation. The method of different mesh generation is used in the junction area of concrete and steel. Approximation of the circular boundary generated by the concrete structure and the cylindrical steel is realized via the octagon structure formed by the basic triangular element. Field sources blessing is achieved in the model area, the principle of absorption and reflection for the incident uniform plane wave signal in model area is analyzed. Boundary conditions of border region are set by using the perfectly matched layer (PML). Model simulation of the model region is realized by the use of C++ language in this paper. Then the subdivision of two-dimensional model area is completed and the experimental data is generated, Analysis of a reinforced concrete structure with the electromagnetic properties by ANSYS.The advantages of analysis and solving in C++ language are fully showed in the finite element method in this thesis. Subsequent development, research and transplantation of analysis software becomes easier due to the programming ideas based on the object-oriented programming. After the realization of finite element method in two-dimensional electromagnetic field, the general concept of using finite element method to slove electromagnetic field is grasped and the superiority of finite element method in computational electromagnetic is demonstrated.