鞍形索网的风振响应特性研究

CHARACTERISTICS OF WIND-INDUCED RESPONSE OF SADDLE-SHAPED CABLE NETS

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。将该方法应用于矢跨比为1/12的鞍形索网结构,通过同步测压试验确定风荷载,对其自振特性、风振响应谱特征、振型参与特性、振型间的耦合效应、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、且低阶振型贡献较大的特点;振型间的耦合效应较明显;脉动风响应明显大于平均风响应,共振响应占主导地位,背景响应所占比例较小。

Wind-induced response is divided into three components, namely, mean response, background response and resonant response. Background response is calculated with structural influence line, and resonant response is analyzed with Ritz-POD method. The method is employed to analyze wind induced response of saddle-shaped cable net with rise-span 1/12. Simultaneous pressure measurements in wind tunnel are done to get fluctuating wind pressure on the building surface. Main characteristics of wind induced response of the structure are analyzed, including structural natural frequency , power spectrum of wind-induced response, modal participation in the response, coupling effects among modes, and distribution rule of three response components. The results show; it is necessary to take into account many vibration modes to calculate wind-induced response, and low-order modes have more contribution to wind-induced response; coupling a-mong modes has important effect on structural response; fluctuating response is larger than mean response, and resonant response is much larger than background response.