单层球面网壳的风振响应特性

为研究大跨度单层球面网壳风振响应特性,通过同步测压风洞试验获取风荷载信息,将风振响应分为平均响应、背景响应和共振响应三部分,其中背景响应采用影响线的方法计算,共振响应采用Ritz-POD法计算.分析过程中,着重对结构自振特性、风振响应中位移和内力的背景响应谱和共振响应谱特征、振型参与特性、以及各响应分量的分布规律进行了研究.结果表明:风振响应明显呈现多阶振型参与振动的特点,且存在高阶振型对脉动风响应贡献最大的现象,结构自振频率分布正好在这一振型处发生明显跳跃;在研究的范围内,脉动风响应大于平均风响应,而且在脉动风响应中,共振响应占主导地位,背景响应所占比例较小.

Characteristics of wind-induced response of single-layer reticulated domes

To analyze the wind-induced response in frequency domain,simultaneous pressure measurements in wind tunnel were done to get fluctuating wind pressure on the dome.Wind-induced response was divided into three components,including mean response,background response and resonant response.Background response was calculated with structural influence line,and resonant response was analyzed with Ritz-POD method.Main characteristics of wind induced response of single-layer reticulated domes were analyzed,including structural natural frequency,power spectrum of background response and resonant response for displacement and internal force,modal participation in the response,and distribution rule of three response components.The results show that it is necessary to take many vibration modes into account to calculate wind-induced response,and there is a high order mode to dominate wind-induced response,which presents a jump in all natural frequencies.In the wind-induced response of single-layer reticulated domes,fluctuating response is larger than mean response,and resonant response is much larger than background response.