【作者】 曾少青；

【导师】 魏德敏；

【作者基本信息】 华南理工大学 ， 防灾减灾工程及防护工程， 2010， 硕士

【摘要】 大跨度空间网架结构是工程中应用十分广泛结构形式,相对于索膜等柔性结构,该类结构的风振响应问题还没有引起足够重视。本文以宁波国际会展中心(二期)大跨度网架屋盖结构风振响应为研究对象,对该结构的风振响应进行了计算机模拟仿真分析。本文主要研究工作包括以下几方面:1.本文以实际工程为算例,利用ANSYS命令流进行力学建模,考虑结构节点间的风速时程相关性,采用AR模型模拟节点随机脉动风速时程,使用自行编制的相关程序,进行了AR法和快速逆傅里叶变换(IFFT)的计算。计算结果表明该方法可有效地模拟具有时间相关性、空间相关性的节点脉动风速时程。得到的风速时程样本的功率谱密度与目标曲线吻合很好。另外还讨论了时间间隔和自回归阶数的取值对结构风荷载模拟的影响。2.用ANSYS软件对结构进行自振特性分析,在上述工作的基础上计算了结构的风振响应,探讨了风速、竖向风、阻尼比、网架高度等基本参数变化对结构风振响应计算结果的影响。3.根据算例分析结果指出现行规范设计方法对空间网架结构不适用之处,认为空间网架结构位移风振系数和内力风振系数不同,进而探讨了结构参数变化对位移风振系数和内力风振系数的影响,所得结果和结论为设计人员进行工程设计提供了参考。更多还原

【Abstract】 The long-span spatial net structure is widely applied in practice engineering., relative to the cable-membrane structure, wind-induced response analysis of this structure is not in percipient.The Ningbo International Conference and Exhibition Center is adopted as an example. wind induced vibration response of the structure is Checked by the computer simulation. The main work is the following parts:1. This paper is based on a practical project. The model of spatial net structure is set up by a series of command in ANSYS. Nodes of the structure associated with wind speed time series are consider, Auto-Regressive (AR) model is employed to simulate node randomly fluctuating wind speed time series. By using programs written by myself, Auto-Regressive (AR) and the inverse Fast Fourier Transform (IFFT) are done. Statistical analysis results of numerical wind speed time series show that the method is efficient in simulating nodal wind speed time series which has time and space correlativity. The power spectrum of wind speed time series sample is coincident with the aim power spectrum curve. Influences of the time interval and autoregressive coefficient on the wind load simulation are discussed.2. The vibration modes of the structure is analyzed by using Finite-element program ANSYS. Calculated wind induced vibration response . The influences of the wind speed, the vertical wind, the height of the net on the wind-induced vibration response of the structure are discussed.3. According to an example of specification design method of the present results indicate that the network structure of space does not apply for space grid structure. Displacement and internal force of the wind vibration coefficient of the structure is different, and discusses the influence of the structural parameters on the displacement and internal force of the wind the wind vibration coefficient, the results and conclusions can provide a reference for engineers.更多还原