【摘要】 大跨屋盖风振响应中的多振型参与特性,及由此导致的多目标等效静风荷载问题,一直是大跨屋盖结构风工程研究和工程应用十分关注的问题。对作者及合作者近年来在该方面的研究工作所取得的进展进行了总结,并加以发展。利用POD分解得到本征模态表达的脉动风荷载空间分布形式,确定与荷载分布形式对应的Ritz向量,即主导模态;推导脉动风响应中背景响应和共振响应的数学表达式,给出背景响应与共振响应间的相关性分析方法;根据结构风振响应特性,以风荷载主要本征模态和结构主导振型惯性力构造多目标等效静风荷载的基本向量,利用最小二乘法得到基本向量的最优组合系数,从而得到针对多个等效目标的等效静风荷载。并通过对跨度40 m的K6型单层球面网壳结构的计算验证本文方法的有效性和准确性。更多还原

【Abstract】 The contribution of higher vibration modes is important to the wind-induced response of long span roofs.A lack of knowledge of this contribution makes it difficult to estimate the wind induced response and equivalent static wind loads accurately.The authors and their research team have been studying this topic for a number of years.Some main research outcomes are presented in this paper.The Ritz-Proper Orthogonal Decomposition(POD) method is applied to choose the dominant modes of the wind-induced response of long span roofs;the eigenvectors of the fluctuating wind load obtained from the POD method are regarded as the spatial distribution of the load to generate the Ritz vectors;the background and resonant response are redefined on the basis of modal acceleration method,and a method to calculate the correlation coefficient between the background response and the resonant response is proposed;the target responses are expressed as the linear combination of the basis vectors,which are the dominant eigen-modes of wind loads and structural vibration modes representing the background and the resonant responses respectively.The combination factors of these basis vectors are determined with the least-squares approximation method.The wind-induced response and equivalent static wind loads of a single layer reticular shell is analyzed as a case study,in which the accuracy and efficiency of the propose methods are verified.更多还原