随机动力荷载激励下建筑结构的基于可靠度优化设计

项目名称： 随机动力荷载激励下建筑结构的基于可靠度优化设计

项目编号： No.51308204

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 建筑科学

项目作者： 王家

作者单位： 湖南大学

项目金额： 25万元

中文摘要： 项目的研究对象为随机动力荷载激励下建筑结构的基于可靠度优化设计。研究内容包括：(1) 线性结构系统的可靠度分析。其中的不确定性来源综合考虑外界随机动力荷载和结构模型参数失真；(2)模拟退火算法及子空间模拟法在研究对象中的应用及比较。作为全局优化方法，模拟退火优化算法将优化问题转化为根据构造的概率密度函数进行随机取样的问题，而子空间模拟法将优化问题转化为在一系列逐渐收缩且靠近全局最优解的空间区域中随机取样的问题。项目通计划通过计算实例应用，比较两种方法在涉及设计变量较多情况下的性能。(3)基于可靠度的优化设计中计算成本的控制研究。为降低计算成本，提高优化设计的计算效率，项目计划考察"极大可能区间"的思想：即根据可靠度分析估计的安全失效概率及其变异系数，估计备选设计对应安全失效概率所在的极大可能区间。针对备选设计进行的可靠度分析所需的最低计算成本需使容许安全失效概率在其提供的极大可能区间之外。

中文关键词： 基于可靠度优化设计；首次穿越可靠度；随机动力荷载；数值模拟算法；全局优化算法

英文摘要： The research focuses on reliability-based optimal design of structures subjected to stochatic dynamic loadings, where the uncertainties in external dynamic loading and structural properties are both considered.The topics that will be fully investigated include:(1)reliability analysis of linear strctures considering uncertainties in structural properties and external dynamic loadings. (2)application of two global optimization algorithms, simulated annealing and subset simulation, in reliability-based optimal design of strcuturs subjected to stochastic dynamic loadings.In simulated annealing,the optimiazation problem is converted into the problem of populating a suitable constrcuted probability density function,which has the largest value at the globla optial design.In subset simulation,the optimization problem is translated into the problem of sampling uniform distribution in a sequence of nested subsets (in the space of design variables), which gradually shrink to the region around the global optimal design.(3)compuation cost reduction in reliability-based optimal design. To reduce the computational cost and enhance the compuational efficiency of the reliability-based optimization algorithm, the idea of 'mininum computational cost' is examined. It is noted that the purpose of reliability analysis in reliability-

英文关键词： reliability-based optimal design；first passage reliability problem；stochastic excitations；simulation method；global optimization