大跨屋盖基于位移响应协方差等效静力风荷载计算方法

目前,频域内有多种等效静力风荷载求解方法,但每种方法都有其局限性;时域内也提出了风致响应的计算方法,却没有完整地提出求解等效静力风荷载的方法。本文基于位移响应协方差矩阵,提出了一种计算大跨屋盖结构等效静力风荷载的新方法。本方法的关键是获得位移响应的协方差矩阵,对于时域法,由于时程分析能得到位移响应时程,故可根据时程序列直接计算得到;对于频域法,也可由各阶模态响应推导得到,因而本方法既适用于时域法,也适用于频域法。最后,以某大跨屋盖结构作为工程实例,计算了等效静力风荷载,并将其与CQC方法计算结果进行了比较,验证了方法的有效性。

Equivalent static wind load based on the covariance of displacement response of long span roofs

At present, in frequency domain, there are a variety of equivalent static wind load methods, but each method has its limitations. In time domain, some wind-induced response calculation methods are presented, but the equivalent static wind load method is not completely presented. In this paper,a new method for equivalent static wind load of long span roofs is firstly presented based on the covariance matrix of displacement. The key of this method is to obtain the covariance matrix of displacement response. In time domain, time-displacement response can be obtained by time-history analysis, so the covariance matrix of displacement can be calculated directly. In frequency domain, the covarianee matrix of displacement can be derived by the modal response. Thus this method is applicable to both time domain method and frequency domain method. Finally, a long span roof is considered to calculate the equivalent static wind load, and to verify the effectiveness with the result of CQC method.