Collaborative Research: Performance-Based Framework for Wind-Excited Multi-Story Buildings

目前的规范性设计理念，简单地依赖于满足标准规定的要求，正在转向基于性能的设计（PBD）的方法，以实现合理满足社会对安全建筑环境的需求的设计。广泛的研究促进了PBD在地震工程中的成功采用，但对于风工程和风灾却不能这么说。风对建筑物的作用不同于地震荷载。风荷载的持续时间较长，其性能对人体舒适度的要求比对地震荷载的要求更高。因此，有必要在建筑系统设计过程中开发一个包含PBD概念的框架，以抵抗严重的风事件。这将为新建筑的设计师和现有建筑的改造者提供一种手段，不仅可以合理评估结构在风中的性能，而且还可以用决策者可以理解的语言传达他们的结果。PBD程序广泛使用的一个主要障碍是其不确定性，这使得传统上涉及设计过程的迭代不切实际。不确定性可以有效地解决特定的优化方案，可以处理的规模和多样性的真实的世界的应用程序的发展。该项目将为多层风激建筑物开发PBD框架，以最佳方式减轻结构和非结构损坏。该方法将明确说明不可避免的不确定性，其特点是对自然灾害的结构响应估计的各个方面。这一目标将通过定义一个有效的风力建筑性能模型来实现，该模型将合理地评估后果和脆弱性函数方面的损坏和损失。为了提高建筑物的性能，将根据一系列风事件（如天气风和飓风）的适当强度测量来定义特定场地的风灾模型。通过确定合适的空气动力学模型，将定义相互作用参数，以驱动以模拟为中心的基于塑性定理的框架，该框架不仅产生风中性能的输入工程需求参数，而且还提供结构系统屈服后行为的完整描述。为了实现最佳地满足性能目标的系统，风PBD问题将被公式化为概率优化问题。通过开发一个通用的解决方案策略，能够有效地处理系统级概率约束和/或目标函数的高维设计变量向量方面的问题，一个集成的PBD和优化方法将被定义，有希望彻底改变目前的风力工程实践。

The current prescriptive design philosophy that relies simply on meeting requirements stipulated in standards is shifting towards a performance-based design (PBD) approach for achieving designs that rationally meet society's need for a safe built environment. Extensive research has facilitated the successful adoption of PBD in earthquake engineering, but the same cannot be said for wind engineering and wind hazard. Wind acts differently on buildings than the earthquake loading. Wind loading is of long duration and performance is more critical for human comfort than for the earthquake loading. Therefore, the need exists to pursue development of a framework that embraces the concepts of PBD during the design of building systems to resist severe wind events. This would offer designers of new buildings and retrofitters of existing buildings a means not only to rationally assess the performance of structures under winds, but also to communicate their results in a language that decision-makers can understand. A major hurdle to the widespread use of PBD procedures is their uncertain nature, which makes the iterations traditionally involved in a design process impractical. The uncertainties can be effectively addressed by the development of specific optimization schemes that can handle the size and diversity of real world applications. This project will develop a PBD framework for multi-story wind excited buildings in order to optimally mitigate structural and non-structural damage. The methodology will explicitly account for the inevitable uncertainty that characterizes all aspects of structural response estimation to natural hazards. This goal will be achieved through the definition of an effective wind building performance model that will rationally assess damage and loss in terms of consequence and fragility functions. To drive the building performance, site-specific wind hazard models will be defined in terms of appropriate intensity measures for a range of wind events, e.g. synoptic winds and hurricanes. By identifying suitable aerodynamic models, interaction parameters will be defined for driving a simulation-centered plastic theorem-based framework that not only yields input engineering demand parameters for performance in wind, but also provides a full portrait of the post-yield behavior of the structural system. In order to achieve systems that optimally satisfy the performance objectives, the wind PBD problem will be formulated as a probabilistic optimization problem. By developing a general solution strategy capable of efficiently handling problems characterized by system-level probabilistic constraints and/or objective functions in terms of high-dimensional design variable vectors, an integrated PBD and optimization methodology will be defined that has the promise to revolutionize current wind engineering practices.