The Finite Element Method For The Optimization Design Of High Arch Dam Based Shape

The shape design of high arch dam is the key technique for the safety and economy of the dam. The adaptability of arch dam to geology is better and better, when the influence of complicated geology is considered, the best way is to use modern calculating optimization design which is widespread now, that is a new challenge to old optimization design system of crown cantilever analysis. The modern calculating optimization design not only needs to solve calculation problem of the different condition and different arch dam parameter full-automatically, but also needs to consider the possibility and the efficiency which were caused by the increments of calculation time.The main tasks of this paper are as follow:Firstly, the situation of optimization design of arch dam and the related realm at present is introduced; the mathematics model and methods of optimization design in high arch dam were presented in details, and then put forward optimization design method of high arch dam based on finite element method (FEM).Secondly, based on the linear elastic finite element calculating theory and mathematics method, the geometry and finite element model of high arch dam are established by the parameter design language(APDL) of the large-scale common finite software ANSYS, and A Steady-State Thermal Analysis is executed by application the temperature load. Applying the water load, deadweight load, and sand load, Reading the results of thermal analysis, to execute the Coupled-Field analysis of thermal-structural solution. Meanwhile optimizing the high arch dam of the parabola, the ellipse and the logarithmic spiral respectively by using optimal module of the finite element software ANSYS. In this paper, the geometrical characteristics parameter of high arch dam were taken as the design variables which were combined of totally 32-40 parameters, dam volume is taken as objective function, considering the restraint condition of geometric, stress and steady condition. The economic and practical shape is searched out in the condition of the dam's stress and stability against sliding all satisfying the require of criterions. The course of optimization design can be automatically carried out and controlled by the computer software, which reduces the time consumed in the repeated design process. The result proves that this procedure is highly reliable, skyscraping efficient and stability convergent. Then this paper discussed correspondingly the arch dam's equivalent stress of finite element, educed the expressions of the arch dam's equivalent stress of finite element, programmed the procedures of arch dam's equivalent stress of finite element based on the software ANSYS. The optimal design for shape of arch dam using equivalent stress of finite element as stress restraint condition is carried out.The optimal design of arch dam based on the finite element method, for a series of work of it such as modeling, load application, solution and optimal calculating all can finish automatically, so it has high efficiency of solution, compact process and high degree of intelligence. The strong after-treatment ability of the software makes the result observing much more convenience and immediacy by kinds of charts, which offer convenience for architect to comprehend the stress and displacement of arch dam.Lastly ,as a practical example, three curve shape of the Laxiwa arch dam were made Optimization respectively, then make a comprehensive evaluation of the three shape optimal designs to be a practical test for the theory.