基于平均风压和脉动风压双基向量的屋盖等效静风荷载确定方法

Equivalent static wind load based on mean wind pressure and fluctuate wind pressure as base vectors for roof structures

大跨屋盖结构的等效静风荷载研究一直有适用性和精确性如何统一的问题。针对此问题提出了一种新的等效静风荷载确定方法,其基本思想是以平均风压和脉动风压为基向量,对结构的极值响应利用最小二乘法进行拟合。该方法的优点是：1）以平均风压及脉动风压为基向量,符合风工程的特点,具有明确的物理意义;2）利用该方法获得的结果和结构真实风振响应吻合良好,精确性高;3）利用该方法可以统计分析得到不同结构的等效静风荷载系数,便于工程应用。对平板网架、单层球面网壳、单层柱面网壳三种典型屋盖结构进行等效静风荷载分析,给出了可供工程应用的等效静风荷载计算表,表中给出位移、支座反力和杆件应力三种等效目标下的平均风压系数和脉动风压系数。

There is a large gap between the applicability and accuracy of equivalent static wind load of long-span roof structures. To solve the problem,a new method to calculate the equivalent static wind load is presented. The basic idea is based on the mean wind pressure and the fluctuate wind pressure as base vectors,the least squares fit is used to analyze the extreme response of the structure. The advantages of this method are： 1） based on mean wind pressure and fluctuate wind pressure as base vectors,it accords with the characteristics of wind engineering and has clear physical meaning; 2） the results obtained by this method are in good agreement with the real wind-induced vibration response of the structure,and the accuracy is high; 3） the equivalent static wind load coefficients of different structures can be statistically analyzed by using this method,which is convenient for engineering applications. The equivalent static wind loads were analyzed of three typical roof structures,including flat-plate grids,single-layer spherical reticulated shells and single-layer cylindrical reticulated shells. The equivalent static wind load calculation table for engineering applications was given,and mean wind pressure coefficient and fluctuate wind pressure coefficient under three equivalent targets including displacement,bearing reaction and stress in rod were given in the table.