Study On Optimum Structural Design For National Stadium And National Swimming Center

National Stadium and National Swimming Center are landmark buildings for 2008 Beijing Olympic Games. The major structure of National Stadium is steel space-frame. The major structure of National Swimming Center is a new type steel space-frame generated by an ingenious method based on the matrix of Weaire-Phelan polyhedron.In present dissertation, a new optimization algorithm named the tow-stage-upward adaptive optimization algorithm is introduced. The ideas of the algorithm come from fully-stressed design and some algorithms of discrete optimum structural design. Using this algorithm, the optimum structural design for major structures of National Stadium and National Swimming Center is presented. In the algorithm presented in the dissertation, the dimensions of the member section are taken as discrete design parameters. Stress constraint and deflection constraint are defined as local constraints and overall constraints respectively. Different types of constraint conditions are treated in different optimum stages to achieve the optimum structural scheme. The local constraints are firstly treated using approximate fully-stressed design method, and the overall constraints are then treated using weight-efficiency design method. The efficiency and accuracy of the algorithm is proved through an example. The algorithm is applicable to complicated structures with numerous members. The optimized structures of National Stadium and National Swimming Center are analyzed and strictly checked according the current building structural codes of China. The static and dynamic reactions of the structures under various load conditions are calculated using FEA computor analysis programs. The mechanics properties of the structures are analyzed. The optimized structures satisfy the restrictions specified in the current building structural codes of China. The results of structural analysis and check show that the optimized structures are not only lighter in weight and also more outstanding in many aspects than the preliminary one. The structural optimum method presented in the dissertation is practical and effective and can be applied to future complicated structures optimum design. The optimized structural schemes provided in the dissertation can be taken as the design references in the future structural design.