预应力双层球面网壳的风振响应与整体风振系数研究

Study on wind-induced response and global wind vibration coefficient of prestressed double-layer spherical reticulated shells

针对预应力双层球面网壳结构,采用Welch谱分析法对谐波叠加法与线性滤波技术(AR法)模拟得到的脉动风速时程进行功率谱精度评价;基于时域分析方法,对预应力双层球面网壳结构的风振响应进行了参数分析,结果表明:网壳的矢跨比、跨度是影响预应力双层球面网壳结构的竖向位移风振响应的主要因素;设置预应力拉索后,结构的节点竖向位移风振系数更小且分布更均匀,表明预应力球面网壳对脉动风效应的敏感性小于普通球面网壳结构。在此基础上,基于包络的概念,采用以最大动响应和最大平均风响应为控制指标,对预应力双层球面网壳结构的整体风振系数进行了研究。

To perform structural analysis of the prestressed double-layer spherical reticulated shell structures,the Welch spectrum analysis method is adopted to evaluate the fluctuating wind speed time-history simulated by the harmony superposition method and linear filter technique.Based on the time-domain analysis,the influence of the structural design parameters on the wind-induced response of prestressed double-layer spherical reticulated shell structures is investigated.Results show that the rise-span-ratio and the span are the main factors influencing the structural wind-induced response.The wind vibration coefficient of double-layer reticulated shells is reduced and averagely distributed with prestressed cables installed;implying that the prestressed spherical shells becomes less sensitive to the fluctuating wind effect.Based on the envelope concept,the maximum structural vibration response and the maximum average wind induced response are adopted as controlled indexes,and then the global wind vibration coefficients of prestressed double-layer spherical reticulated shells are investigated.