中文摘要：

为工程提出了一种投资一效益模型的结构评估方法．基于结构体系最弱失效模式分析的理论，应用优化和控制方法研究结构体系可靠度设计．根据结构体系可靠度失效模式的概率特征，引入结构体系最弱失效模式理论，提出了优化设计结构体系的最弱失效模式组来实现提高结构体系可靠度目标；基于各最弱失效模式对应的可靠指标矢量与各基本变量的关系，确定主要影响因素；提出了一种基于结构最弱失效模式组的投资一效益优化模型，并通过实际算例进行验算．该方法可以较好地计算结构费用，基于结构最弱失效模式组的投资效益模型的优化可以达到优化结构的目的，该研究对结构体系可靠度分析与设计的基础研究具有一定的意义．

英文摘要：

An investment-benefit model was developed that helps to minimize the costs of failure prevention in engineering. Based on the theory of the weakest failure modes of structural systems, the structural system reliability design was approached using the optimization and control method. It showed that structural system reliability can be optimized and controlled by optimizing the weakest failure modes. The main factors influencing failure were defined by interrelationships in the rules of reliability, the index vector, and the failure mode. An investment-benefit optimization model based on the weakest failure modes of structural systems was presented. The effectiveness of our method was verified by its practical application. The method was able to calculate structural costs in a better way, with optimization of structural systems achieved by optimization of the investment-benefit based on the weakest failure modes. The work provides important research for the foundation of structural system reliability, analysis, and design.