考虑模糊可靠度的抗震结构优化设计

OPTIMUM DESIGN OF ASEISMIC STRUCTURES CONSIDERING FUZZY RELIABILITY

在结构优化的目标函数中，不仅应考虑结构造价，而且应考虑结构服役期的损失期望。为此，我们定义了抗震结构模糊可靠度的概念。利用抗震设计原则和地震危险性分析给出了一个计算模糊可靠度的方法。然后提出了三步优化法；第一步，寻求一系列对应于不同设防烈度的最小造价设计；第二步，同时考虑造价和地震引起的损失期望，寻求最优设防烈度；第三步，寻找相应于此最优烈度的最小造价设计。

Not only structural construction cost but also loss expectation in the service life of the structure should be considered in the objective function of structural optimization.For this purpose the concept of fuzzy reliability for aseismic structures is defined.An algorithm to calculate the fuzzy reliability is obtained,which uses the advantages afforded by the aseismic design principle and the seismic hazard analysis.Then,a three step optimum design procedure is presented.The first step is to find out the set of minimum cost design points corresponding to different defense intensity.In the second step,both construction cost and earthquake caused loss expectation are traded off to find the optimum defense intensity.In the third step,the minimum cost design scheme corresponding to the optimum defense intensity will be found out.