Analysis Of Finite Element Mesh Generation Program And Its Accuracy

With the speedy development of computational mechanics and the massive project practice, the finite element method, with its special advantage, has been applied to stress analysis of arch dam widely. The complicated structure of arch dam, heterogeneity of dam foundation, construction process can be considered conveniently on this method. The finite element method can solve lots of questions which are very difficult on the trial load method, so it has the bright future.The basic process of finite element analysis can be divided into three stages: create the finite element model (namely pretreatment), solve, process and evaluate the result (namely post-processing). The meshing method is one of the most important steps in a finite element analysis, it directly affects the accuracy of the calculation results. As a special structure for arch dam, only by establishing a correct and reasonable finite element model of arch dam, it can correctly reflect the working condition of arch dam, then properly reflect stress condition. So the study of scheming finite element mesh dissection of arch dam has very important significance.The capital work of this paper are as follows:Based on the massive domestic and foreign materials, the paper summarizes the structure feature of arch dam, the development situation of arch dam, the actuality of stress analysis methods and finite element analysis method; The paper introduces the basic theory of finite element method, deduces the basic formulae; States the units and suitable condition of finite element method, and the influence factors of stress of arch dam and the finite element calculation accuracy are analyzed theoretically; Introduces the finite element meshing methods based on ANSYS and the basic principle for arch dam meshing; Takes large-scale general finite element analysis software ANSYS as the platform, works out command stream by useing the secondary developing technique APDL, creates three kinds of geometry models of arch dams and foundation (the high of arch dam is 100m,200m,300m respectively); Takeing these three kinds of arch dams for the example, the stress of arch dam with different meshing methods is analyzed, and the influence of stress of arch dam and the finite element calculation accuracy is discussed in selection of the element-form, element-size, element-density and node numbers and so on. The criteria of FEM meshing for arch dams is put forward, providing an effective reference for correct and reasonable finite element model of arch dam.