结构的时变可靠性分析及全寿命优化的最优控制理论方法

Important engineering structures have several features such as small failure probabilities, huge fabrication cost and failure loss, and gradual degradation during service lifetime. Time dependent reliability analysis and life cycle cost optimization of such structures are crucial for guaranteeing the safety and economy. This project proposes an effective method for time-variant reliability analysis, and construct a new framework for life cycle optimization of deteriorating structures. The study includes, (1) To build a time variant structural reliability model based on the degradation rule and taking into account the real-time structural detection data, and to develop a new effective method of computing time-variant reliability. (2) To study a synthetic design model of optimizing both the maintenance strategy and structural parameters. (3) To construct an optimal control framework for general life cycle optimization problems, and propose a hybrid solving method based on conventional optimization algorithms together with the dynamic programming. (4) The proposed model and the computing algorithms will be displayed and validated through examples such as bridges, shield tunnels and marine pipelines subjected to degradation.

长寿命工程结构在服役期会伴随性能退化，且具有初始建造费用高、失效概率低但失效损失大等特征。考虑内外因素影响，对结构进行时变可靠性分析并进行全寿命优化分析，对于保障结构功能性和安全性十分关键。本项目建立和发展有效的结构时变可靠性分析和计算方法，并研究结构全寿命优化一般问题的最优控制理论模型，提出同时优化结构参数和维护决策的新思路和新方法。内容包括：(1) 、基于性能退化规律、随机过程理论、检测信息和贝叶斯理论，构建结构时变可靠性分析模型和可靠度动态更新原理，同时发展和完善新的时变可靠度计算方法。(2)、以结构时变可靠性模型和分析方法为基础，研究结构设计和维护方案的一体化优化建模。(3)、搭建全寿命优化的最优控制理论模型，综合利用已有的优化方法和动态规划法，实现结构参数和维护策略的一体化设计。(4)、通过桥梁、盾构隧道、海洋管道等时变问题算例，展示本模型和方法的有效性。