基于场相关效应和结构性态的工程台风建模及其应用

It is vitally important to get the design wind parameters of engineering fields whatever for safety or economic purposes during typhoon-resistance assessment. The existing typhoon models used for Civil Engineering always have the shortcomings of over simplified theoretical frames, so could not easily reillustrate distribution characteristics of wind velocity including the specific wind profiles, convection shear and decay effects during landfall. The corresponding calculations and conclusions inevitably depend on posterior modification based on the on-the-spot observations. Its applications in engineering design are restricted due to the above reasons. The plan will consider the correlating effects of multiple fields, such as wind pressure field, wind velocity field and geometric dimension field, in the layer of basic physical equations, then quantitatively describe the strong randomness and decay effects of those field parameters during typhoon landfall, numerically deduce the evolution of wind velocity field in the atmospheric boundary layer, finally build the velocity field model servicing typhoon-resistance design for Civil Engineering, which should be symmetrically validated by actual observed data. Aiming at the issue of selective control about various wind parameters, such as various wind parameter indices under typhoon conditions show selective sensitivities for the certain wind-induced performance of the structures with different types and dimensional sizes, two kinds of horizontal and vertical flexible line-type structures commonly-used in Civil Engineering will be selected to conduct case studies, the reasonable rules relating to designing wind parameters and structure behaviors will be determined and validated with the help of finite element analysis and active wind tunnel testing techniques. On the basis of above workings, Monte-Carlo numerical simulation will be conducted for wind environment prediction for typical engineering fields under the typhoon climate, and wind velocity zoning map for typhoon-prone coastline regions of China would be proposed.

获取工程场地台风设计风参数对建筑结构安全和经济设计至关重要。现存的多种土木工程台风模型均存在理论体系过度简化的问题，难于再现台风过程特异性风剖面、对流切变和登陆衰减等制约结构设计的时空风速分布效应，计算结果过度依赖实测数据后验修正，限制其在工程设计风速预测中的应用。本项目拟在基本物理方程层面考虑台风条件风压场、风速场和尺度场关键参数之间的相关特性，量化描述台风场参数强变异性和登陆衰减效应，推演近地边界层风速场随台风发展演变规律，建立涵盖多种关键效应并适用于土木工程领域的台风风场模型，并利用实测资料验证其有效性；针对多样化的台风设计风速指标相对不同类型和规模结构风致行为性态的选择控制性问题，结合土木工程中两类典型水平和竖向柔性线状结构，利用有限元计算和主动风洞试验方法比选和验证设计风参数取值原则。在此基础之上，开展台风气候工程场地设计风环境概率化数值模拟，形成我国沿海区域台风设计风速区划图。

本项目在基本物理方程层面考虑台风条件风压场、风速场和尺度场关键参数之间的相关特性，量化描述台风场参数强变异性和登陆衰减效应，推演近地边界层风速场随台风发展演变规律，建立涵盖多种关键效应并适用于土木工程领域的台风风场模型，并利用实测资料验证其有效性。在此基础之上，开展台风气候工程场地设计风环境概率化数值模拟，基于全球地貌和海拔高度数据，提出了考虑上游地貌地形影响的风速近似修正方法；建立了靠近我国沿海184个台风级别热带气旋的极值风速灾害图。针对多样化的台风设计风速指标相对不同类型和规模结构风致行为性态的选择控制性问题，结合土木工程中两类典型水平和竖向柔性线状结构，利用有限元计算和主动风洞试验方法比选和验证设计风参数取值原则。选择超大型双曲面钢结构冷却塔的风致性能研究作为工程案例，比较了钢结构冷却塔和钢筋砼冷却塔的动力特性，分析比较了风致位移特征和模态参与特征，比较了位移风振系数分布特征，量化比较了位移风振系数对结构阻尼比的敏感性。为了再现复杂的风致结构振动，本项研究提出并设计了一种新型的可随机运动强迫振动装置。与以往的设备相比，它能够实现更多种多样的运动类型，因此可以再现随机振动过程，论述了该装置的设计原理及其在风工程中的应用前景，探讨了强迫振动装置的设计方面主要介绍了现有的运动类型、振动幅度、PID闭环控制方法及其在精度和可行性两方面的验证，讨论了强迫振动装置在风工程领域的应用拓展，包括典型断面非稳态气动力特性、飞行器气动力、风-车-桥耦合、桩土共同作用、输电线-塔耦合振动等。利用安装在西堠门大桥上结构健康监测系统的超声风速仪所获得的健康监测数据，基于极坐标分解并分析了四次台风实测记录，获得台风脉动风几个重要参数的相关关系，阐明台风的非高斯特性可能与台风结构内相对位置相关，最利用Hermite多项式建立了非高斯台风脉动风模拟算法。