强迫振动条件下大跨柔性屋盖非定常风荷载特性的大涡模拟

发布时间：2018-06-06 09:51

本文选题：大跨柔性屋盖 + 大涡模拟　；参考：《北京交通大学》2017年硕士论文

【摘要】：大跨柔性屋盖被广泛应用于体育场馆、会展中心、机场航站楼等多种大型建筑中。由于具有轻质柔性特征,其在风的作用下常出现大幅振动与失稳破坏现象,情况严重时甚至会造成重大经济损失和人员伤亡。本文利用数值模拟方法,结合理论与既有试验数据对强迫振动条件下大跨柔性屋盖的风荷载特性、绕流特性及非定常气动效应进行研究,具体内容如下:(1)阐述了采用大涡模型模拟强迫振动屋盖绕流风场的理论基础及技术问题,给出了模拟均匀湍流与大气边界层湍流来流的过程,介绍了振动屋盖数值模型的动网格更新方法。(2)利用计算流体动力学软件FLUENT建立大跨柔性屋盖的数值风洞试验模型,论证了模拟强迫振动条件下屋盖表面风荷载特性的可行性与合理性,研究了数值模型维度与来流湍流对计算结果的影响。(3)根据数值模拟结果,比较了强迫振动条件下,大跨平面屋盖与曲面屋盖表面风荷载特性的异同,分析了屋盖的平均与脉动风压分布特性、风压的非高斯特性及频谱特性随强迫振动频率的变化。(4)利用简化气弹力学模型,研究了大跨柔性屋盖的非定常气动力特性,并利用机械导纳函数预测了大跨柔性屋盖的动力响应,分析了非定常气动力对结构动力响应的影响。
[Abstract]:Long span flexible roof is widely used in many large buildings, such as gymnasium, convention center, airport terminal and so on. Because of its light and flexible characteristics, large vibration and instability often occur under the action of wind, and even cause heavy economic losses and casualties when the situation is serious. In this paper, the wind load characteristics, flow characteristics and unsteady aerodynamic effects of long-span flexible roof under forced vibration are studied by using numerical simulation method and theoretical and experimental data. The main contents are as follows: (1) the theoretical basis and technical problems of simulating the wind field around the forced vibration roof by using the large eddy model are described, and the process of simulating the uniform turbulence and the turbulent flow in the atmospheric boundary layer is given. The dynamic mesh updating method for the numerical model of vibrating roof is introduced. The numerical wind tunnel test model of long span flexible roof is established by using the computational fluid dynamics software FLUENT. The feasibility and rationality of wind load characteristics on roof surface under simulated forced vibration are demonstrated. The effects of numerical model dimension and incoming turbulence on the calculated results are studied. The differences and similarities of wind load characteristics on the surface of long-span plane roof and curved roof are analyzed. The distribution characteristics of mean and pulsating wind pressure, the non-Gao Si characteristics of wind pressure and the frequency spectrum characteristics of wind pressure with forced vibration frequency are analyzed. The unsteady aerodynamic characteristics of long span flexible roof are studied, and the dynamic response of long span flexible roof is predicted by using mechanical admittance function, and the influence of unsteady aerodynamic force on the dynamic response of structure is analyzed.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU312.1

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