台风下中/小尺度模式耦合的航站楼屋盖非线性振动机理及应用基础研究

Partial or whole damage of roofs under the typhoon is the main form of wind-induced damage of airport terminal, research on nonlinear and aero-elastic effects, needs to be conducted especially when more flexible roofs are mainstreaming in the future. The existing analysis methods have the shortcomings of over simplified theoretical frames for flow field model and solid-fluid coupling system, so could not easily reillustrate characteristics of turbulence of small scale roofs and coupling effects of vortex shedding, including mesoscale typhoon wind profile and decay effects during landfall. The plan will combine the measured data of macro typhoon, the mesoscale WRF high-precision simulation model which considering the real strong randomness and decay effects of those field parameters during typhoon landfall will be established. Meanwhile the method coupling mesoscale typhoon wind field with small scale of roofs flow fields will be researched, and the problems such as the flow structure in the transmission, time scale control and mutations across scales in the coupling will be emphatically resolved, thus the high precision flow field of the roofs with medium/small scale (WRF/DES) mode coupling method under typhoon will be established. Nonlinear effects will be further considered in the project of the existing time domain CFD/CSD tight coupling algorithm platform, and failure pattern of roofs, the nonlinear vibration and energy transfer mechanism in the whole process of the typhoon transit will be researched, and the wind vibration control measures based on vibrational energy transfer and accumulation to neglected modes will be put forward. This project is expected to enrich wind engineering theory of structures and lay the foundation for the nonlinear wind-resistant design of large span roofs.

台风作用下屋盖局部或整体损毁是机场航站楼风致破坏的主要形式，非线性和气弹效应是屋盖轻柔化发展亟待研究的问题，现有分析方法均存在流场模型和流固耦合体系过度简化的问题，难于再现中尺度台风特异性风剖面和登陆衰减等与小尺度屋盖结构特征湍流及漩涡脱落相匹配的耦合效应。本项目拟结合宏观的台风实测资料，建立考虑真实台风场参数强变异性和衰减效应的中尺度WRF高精度仿真模型；研究将中尺度台风风场与小尺度屋盖流场耦合的方法，着重解决耦合中的流动结构传递、时间尺度控制和跨尺度突变等问题，从而建立台风下中/小尺度模式（WRF/DES）耦合的屋盖高精度流场。在项目组已有CFD/CSD时域紧耦合算法平台上进一步考虑非线性效应，研究台风过境全过程屋盖破坏形态、非线性振动和能量传递机理。最终，针对性地提出基于振动能量向高阶模态转移并积聚的风振控制新措施。本项目研究将丰富结构风工程理论，为大跨度屋盖非线性抗风设计奠定基础。

航站楼作为提供飞机乘客转换陆上和空中交通的多功能设施，轻量化、大型化导致该结构屋盖体系风损风毁问题更加突出，尤其是在强台风频繁发生的东南沿海地区。与良态风相比，台风作用下近地面风场高湍流、多突变、强切变等风场特性显著加剧航站楼结构近壁面气流运动形式的紊乱性，造成屋盖表面平均风压突变、瞬时极值风荷载过大、脉动风压伴随出现非高斯特性等特征。加之现存结构抗强/台风研究大多基于理论分析和实测数据，存在理论体系过度简化问题，难以真实反映中尺度台风场的特异性风剖面和登陆衰减效应。本研究主要结合宏观的台风实测资料，建立了考虑真实台风场参数强变异性和登陆衰减效应的中/小尺度（WRF/DES）模式耦合的航站楼屋盖流场高精度仿真模型，着重解决了中/小尺度耦合中的流动结构传递、时间尺度控制和跨尺度突变等问题。在项目组已有的CFD/CSD时域紧耦合算法平台上进一步考虑柔性屋盖结构的非线性效应。研究了在台风不同区域和过程下屋盖结构的破坏形态、非线性振动和能量传递机理；针对性地提出了基于振动能量转移的风振控制新措施。因此，本研究建立的中/小尺度模式耦合下的WRF-DES-CSD时域紧耦合算法，将有助于深入认识此类大跨度屋盖结构在台风下的非线性振动特性与能量作用机理，推动大跨度空间结构非线性风振理论的建立和发展。