杭州湾大桥北航道桥结构优化研究

应用三维空间有限元模型,进行斜拉桥结构优化设计。利用有限元法进行结构分析,求出优化所需的状态变量,挠度、应力和频率。综合考虑设计变量、状态变量和目标函数的联系,应用混合罚函数建立优化模型。运用一阶优化计算方法和引入灵敏度分析进行算法优化,使结构在应力、变形和频率等约束条件下达到最小造价。以通用有限元软件ANSYS作为平台,编制相应程序,综合考虑斜拉桥结构静力性能和动力性能,用两种不同方案对杭州湾大桥北航道桥主桥进行结构优化设计,使全桥造价分别降低9 1%和5 5%。

Study on Northern Channel Bridge Structure Optimization of Hangzhou Bay Bridge

The design of the cable stayed bridge structure is optimized by using 3-D space finite element model. The finite element method is employed to analyze the structure and work out the status variables required by (optimization) including deflection, stress and frequency. The paper takes a systematic view of the relation (between) the design variables, the status variables and the target function and builds the optimization model with the mixed penalty function. The paper uses the first order optimized calculation method and introduces the (sensitivity) analysis to carry out the arithmetic optimization. Thus the structure can be completed at the minimum cost under the constraint condition of stress, deformation and frequency. On the platform of ANSYS, the (corresponding) program is compiled and the static performance and dynamic performance of the cable stayed bridge structure is considered in an all-round way. Two different solutions are used to complete the structure (optimization) design of the main bridge of the north channel bridge of Hangzhou Bay Bridge. The design results in the reduction of the total cost by 9.1% and 5.5% respectively.