Assessing Probabilistic Extreme and Fatigue Responses of Wind-Excited Structures through Integration of Both Uncertainty and Directionality with a System Perspective

从系统角度整合不确定性和方向性来评估风激结构的概率极端和疲劳响应

• 批准号: 1536108
• 负责人: Xinzhong Chen
• 金额: $ 29.82万
• 依托单位: Texas Tech University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-01 至 2020-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1536108&HistoricalAwards=false
• 关键词: Assessing; Probabilistic; Extreme; Fatigue; Responses

Better modeling and quantification of wind load effects on buildings and structures are essential for structural design and wind hazard mitigation. Wind tunnel studies and structural dynamic response analysis provide information of wind-induced extreme and fatigue responses as functions of wind speed and direction. The overall structural performance to strong wind is then evaluated by a further consideration of variations of wind speed and direction. As the most unfavorable wind direction that causes the largest wind load and structural response under given wind speed does not necessarily align with the direction of strongest wind, consideration of directionality effects can result in more economical design of structures as compared to the analysis with the "worst case" approach of disregarding wind directionality. The discrepancies of predictions from current existing approaches on directionality effect are found to be significant. Furthermore, these approaches cannot account for uncertainty and directionality in a unified framework. Due to a lack of scrutiny on the accuracy and effectiveness of these approaches, and a lack of a unified approach for both uncertainty and directionality, the detailed and comprehensive wind loading information derived from wind tunnel studies may not necessarily lead to expected improvement in the design of wind-excited structures. This research will consider the uncertainty and directionality of wind, aerodynamics, and structural characteristics in a unified framework with a system perspective. Simplified procedures will be developed for possible use in future design codes and standards. The new tools and knowledge can also be used for performance-based design and assessment of structural systems against multiple hazards.The goal of this research is to investigate transparent and reliable approaches for better assessing probabilistic multiple limit state responses to support a reliability and performance-based design of wind-excited structures. This research has the following objectives: 1) modeling of probabilistic extreme and fatigue responses of non-Gaussian response processes, 2) modeling of directional extreme wind speeds, 3) prediction of probabilistic extreme and fatigue responses considering both uncertainty and directionality, and 4) assessing structural performance with the effects of uncertainty and directionality accounting for multiple limit-state responses. The research findings will help develop consensus on how wind directionality effects are best quantified, thus the large discrepancies of existing approaches can be reduced or eliminated. The framework will also help wind engineering laboratories to better integrate wind tunnel study results with wind modeling for cost-effective design of structures to wind loads.

更好地建模和量化风荷载对建筑物和结构的影响是必不可少的结构设计和风灾缓解。 风洞研究和结构动力响应分析提供了作为风速和风向函数的风致极值和疲劳响应的信息。然后，通过进一步考虑风速和风向的变化来评估结构的整体强风性能。 由于在给定风速下引起最大风荷载和结构响应的最不利风向并不一定与最强风的方向一致，因此与忽略风向的“最坏情况”分析方法相比，考虑方向性效应可以使结构设计更经济。 从目前现有的方法预测的方向性效果的差异被发现是显着的。此外，这些方法无法在一个统一的框架内解释不确定性和方向性。由于缺乏对这些方法的准确性和有效性的审查，以及缺乏对不确定性和方向性的统一方法，从风洞研究中获得的详细而全面的风荷载信息可能不一定会导致风激结构设计的预期改进。 这项研究将考虑风的不确定性和方向性，空气动力学和结构特性在一个统一的框架与系统的观点。将制定简化程序，以便在今后的设计规范和标准中使用。新的工具和知识也可以用于基于性能的设计和评估的结构系统对multiplehazards.The研究的目标是调查透明和可靠的方法，更好地评估概率多极限状态响应，支持可靠性和基于性能的设计风激结构。 本研究有以下目的：1）建模的概率极值和疲劳响应的非高斯响应过程，2）建模的方向极端风速，3）预测的概率极值和疲劳响应的不确定性和方向性，和4）评估结构性能的不确定性和方向性的影响，占多个极限状态响应。研究结果将有助于就如何最好地量化风的方向性效应达成共识，从而减少或消除现有方法的巨大差异。 该框架还将帮助风工程实验室更好地将风洞研究结果与风建模相结合，以实现风荷载结构的成本效益设计。