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针对我国《建筑结构荷载规范》中风振系数基于准定常理论和一阶线性振型假定存在的问题,以及大跨度屋盖、低矮房屋和类圆柱形断面结构由于自身形状引起的特征湍流和漩涡脱落导致其表面脉动风压分布呈现出的非高斯现象,以Davenport提出的阵风荷载因子法(GLF)为理论基础,通过风洞刚体测压试验获取结构表面的非定常气动力参数,引入参数ρ这一修正项来考虑局部测点风压系数和整体阻力系数之间的相关性;为避开GLF法基于高斯分布的假定提出基于保证率的逐步迭代法来计算峰值因子g;引入虚拟激励法这一高效计算手段,采用振型叠加法计算结构响应的均方根,然后采用给出的计算公式得到满足工程保证率的风振系数值。最后通过某大跨度结构的不同方法计算结果和精确解的对比验证了该方法的可靠性和优越性。这一方法可为建筑结构抗风设计、防灾分析提供借鉴。
In view of the problems existing in the mid-course wind vibration coefficient of China’s “Building Structure Load Code” based on the quasi-stationary theory and the first-order linear mode hypothesis, as well as the characteristics of turbulence and vortices caused by the shape of long-span roofs, low-rise buildings and cylindrical- The non-Gaussian phenomenon caused by the shedding wind pressure caused by shedding is taken as the theoretical basis. Based on the gust load factor method (GLF) proposed by Davenport, the unsteady aerodynamic parameters of the structure surface are obtained by the rigid-body piezometric pressure test in wind tunnel. This correction term is used to consider the correlation between local measured wind pressure coefficient and the overall drag coefficient. To avoid the GLF method based on the assumption of Gaussian distribution, a step-by-step iterative method based on guaranteed rate is adopted to calculate the peak factor g. This efficient calculation method uses the modal superposition method to calculate the root mean square of the structural response, and then uses the given formula to get the wind-induced vibration coefficient value that meets the project guarantee rate. Finally, the reliability and superiority of the proposed method are verified by comparing the results of different methods and the exact solution of a long-span structure. This method can provide reference for wind-resistant design and disaster prevention analysis of building structures.