Efficient Reduced-Order Modeling Tools for Aeroelastic Predictions in Super Long-Span Bridges

用于超大跨度桥梁气动弹性预测的高效降阶建模工具

• 批准号: 1031036
• 负责人: Pier Marzocca
• 金额: $ 30.01万
• 依托单位: Clarkson University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-01 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1031036&HistoricalAwards=false
• 关键词: Efficient; Reduced; Order; Modeling; Tools

Wind-induced vibration of super-long-span bridges is a major concern for bridge designers. The wind can induce problematic vibration in two different ways. One way is the vibration induced by the periodic shedding of vortices that are enhanced by coupling with bridge motion; this is Vortex-Induced Vibration. The second way is the high-speed winds associated with severe storms; in this situation, flutter, among other fluid-structure interaction phenomena, is a major concern for its catastrophic nature. Thus there is a need to enhance the design technology through the development of improved computational capability that takes into account critical fluid mechanical phenomena that potentially induce problematical vibration of flexible bridges. A multi-disciplinary research effort devoted to advanced modeling of flexible long-span suspension bridges is planned. The research is targeted to the development, validation, and application of relatively sophisticated analysis tools to model highly unsteady flow over bridge decks associated with uniform and other important wind conditions and with the nonlinear flexible structures with torsional, bending, and axial modes excited. The main focus of this research is the development and application of new reduced-order models based on unsteady aerodynamic non-linear indicial functions to investigate long-span wind-induced bridge-structure vibration with two major outcomes: (i) the availability of powerful and affordable computational tools for aeroelastic predictions in bridges and (ii) an improved understanding of the aerodynamic instabilities, their triggering mechanisms and hints on how to prevent them. With the development of advanced aeroelastic modeling and computational techniques, engineers will be able to examine the inherent structural flexibility of long-span bridges coupled with aerodynamic nonlinearities due to fluid-structure interactions. The broader understanding of how elastic structures respond to wind should lead to new design criteria and insights for new design paradigms for long span bridges, wind turbines, skyscrapers, only to name a few. The results of this research will advance the knowledge of nonlinear fluid-structure interaction modeling of long- and super-long-span bridges and many other flexible structural systems exposed to aerodynamic loading. The results will also be useful to the engineer interested in retrofitting existing bridges with passive and active flow controls and other modifications as well as help engineers interested in developing improved structural health monitoring strategies.

超大跨度桥梁的风振问题一直是桥梁设计人员关心的问题。风可以通过两种不同的方式引起有问题的振动。一种方式是由周期性的涡流脱落引起的振动，这些涡流与桥梁运动耦合而增强，这就是涡激振动。第二种方式是伴随着强烈风暴的高速风；在这种情况下，颤振以及其他流固相互作用现象是其灾难性性质的主要问题。因此，有必要通过发展改进的计算能力来提高设计技术，以考虑可能导致柔性桥梁有问题的振动的关键流体力学现象。计划进行一项多学科的研究工作，致力于柔性大跨度悬索桥的先进建模。这项研究的目标是开发、验证和应用相对复杂的分析工具，以模拟均匀和其他重要风条件下的桥面高度非定常流动，以及具有扭转、弯曲和轴向激励模式的非线性柔性结构。这项研究的重点是基于非定常气动非线性指标函数的新型降阶模型的开发和应用，以研究大跨度桥梁结构的风致振动，主要结果有两个：(I)可用于桥梁气动弹性预测的强大且负担得起的计算工具的可用性；(Ii)对空气动力不稳定性、其触发机制和如何预防的提示的更好的理解。随着先进的气动弹性建模和计算技术的发展，工程师们将能够研究大跨度桥梁固有的结构柔性以及由于流固耦合而产生的气动非线性。对弹性结构如何响应风的更广泛的理解应该会导致新的设计标准和对大跨度桥梁、风力涡轮机、摩天大楼等新设计范例的洞察，仅举几例。本文的研究成果将对大跨度、超大跨度桥梁等多种柔性结构系统在气动荷载作用下的非线性流固耦合建模有一定的借鉴意义。研究结果也将有助于对现有桥梁进行被动和主动流量控制和其他修改的工程师，以及对开发改进的结构健康监测策略感兴趣的工程师。