Stress Analysis Of Arch Dams By Adaptive Finite Element Method

After introducing principles of adaptive finite element method (AFEM), h-type AFEM is applied in analysis of stress in arch dam, and a new posteriori error estimator named iterative algorithm is presented in this paper. According to the analysis of distribution characteristics of the stress and posteriori error in dam body, an error criterion has been proposed, which is measured by the posteriori error of the middle surface of arch dam. To use this criterion help us overcoming the non-convergence problems of posteriori error caused by the singular stress and non-homogeneous materials. Additionally, admissible values of system error, the average error and the maximum error in the middle surface are proposed. Thus a stress analysis system used in arch dam based on h-type AFEM and a complete error system composed of iterative algorithm, error criterion and admissible errors are established.All of six chapters in this paper are listed below:Chapter 1: Design theories of arch dam and calculation methods of stress are retrospect. The lacks of stress criterions in current design specification for concrete arch dams are discussed.Chapter 2: Basic principles of elastic FEM are introduced. The properties of stress solutions are analyzed, and posteriori treatment methods of stress are give.Chapter 3: Basic principles of AFEM and its types are detailed. Posteriori error estimate and adaptive generation of elements, which are the two main techniques of AFEM, are discussed.Chapter 4: A new posteriori error estimator named iterative algorithm is presented.Chapter 5: According to the analysis of distribution characteristics of the stress and posteriori error in dam body, an error criterion has been proposed, which is measured by the posteriori error of the middle surface of arch dam. And a error system is presented.Chapter 6: The AFEM stress analysis system for arch dams is introduced.Chapter 7: The main contents of this paper are summarized. Lacks and application prospects of AFEM stress analysis system are pointed out, and the further researches are discussed.