LCE: Reliability-Based Simulation for Performance-Based Design

这项基于建模和仿真的生命周期工程（LCE）工程科学拨款为先进计算工具的开发提供资金，用于预测复杂结构系统对极端自然现象危害的反应，分析不确定性和管理风险。将开发时变结构可靠性方法，以提供不确定环境模型、结构系统物理模型及其性能要求之间的接口。数据库和其他来自实验或现场数据、模型模拟和专家意见的信息将使用计算贝叶斯框架合并。高效的技术评估结构性能在不确定性下使用锐化的方法来确定包含-排除界限，将进行研究。这些方法将通过一个当前非常有趣的试验台问题来演示：建筑结构系统在剧烈地震随机地面运动下的脆弱性建模。如果成功，本研究中开发的决策工具将为复杂的民用基础设施在其50至100年的使用寿命期间提供一个生动的画面，这可以作为新的基于性能的设计范式和管理极端自然灾害造成的设施风险的基础。在最近对地震和飓风期间建筑性能的灾后评估中，人们发现，当前的设计实践并不能防止非危及生命的结构损坏和功能中断，这可能导致直接的经济和机会成本接近或超过结构成本。公众要求工程解决方案具有更可预测和控制的性能，更高的耐用性和更低的生命周期成本。在适当的民用基础设施试验台问题上展示先进的决策理论技术将加速改进和加强建筑技术和结构设计方面的竞争，最大限度地减少对原型测试的需要，并降低自然灾害造成的死亡、伤害和财产损失的风险。

This Engineering Sciences for Modeling and Simulation-Based Life-Cycle Engineering (LCE) grant provides funding for the development of advanced computational tools to forecast the response of complex structural systems to extreme natural phenomena hazards, to analyze uncertainties, and to manage risk. Time-dependent structural reliability methods will be developed to provide the interfaces between models of the uncertain environment, physical models of the structural system, and its performance requirements. Databases and other information from experiment or field data, model simulation, and expert opinion will be incorporated using a computational Bayes framework. Highly efficient techniques for evaluating structural performance under uncertainty using sharpened methods for determining inclusion-exclusion bounds, will be investigated. The methods will be demonstrated using a testbed problem of significant current interest: fragility modeling of building structural systems subjected to severe earthquake stochastic ground motions.If successful, the decision tools developed in this research will provide a living picture of a complex civil infrastructure facility during its service life of 50 to 100 years, which could be used as a basis for the new performance-based design paradigm and for managing facility risk due to extreme natural hazards. In recent post-disaster assessments of building performance during earthquakes and hurricanes, it has been found that current design practices do not prevent non-life-threatening forms of structural damage and functional disruptions that may lead to direct economic and opportunity costs that approach or exceed the cost of the structure. The public is demanding engineering solutions with more predictable and controlled performance, greater durability, and lower life-cycle costs. A demonstration of advanced decision-theoretic technologies on an appropriate civil infrastructure testbed problem would accelerate improvements and enhance competition in building technologies and in structural design, minimize the need for prototype testing, and lower the risk of death, injury and property damage from natural hazards.