肋环型单层曲板网壳结构的风振响应及等效静风荷载

分析了肋环型单层曲板网壳结构的风荷载和风振响应,并对采用不同方法计算结构等效静风荷载的精度进行了比较.风洞试验结果表明:肋环型单层曲板网壳结构屋面主要受负风压作用;但在90°风向角下,由于体育馆受前方入口建筑的影响,屋盖边缘局部出现正风压.风振响应分析结果表明:有多阶振型参与结构的风致振动,高阶模态影响不可忽略;为保证结构表面所有节点位移准确,结构的模态耦合项不能忽略.但如果只保证较大位移处的准确性,忽略模态耦合项的SRSS方法也是可取的.利用LRC惯性力法和改进LRC方法计算肋环型单层曲板网壳结构的等效静风荷载,可以保证所有风向角下节点的最大位移等效,但不能保证所有节点的位移等效.

Wind-induced response and equivalent static wind load of single-layer Geiger lattice shell with curved plate

The wind pressure and the wind-induced vibration of a single-layer Geiger lattice shell with curved plate are analyzed.Different methods are used to calculate the equivalent static wind load,and the calculation accuracy are compared.The results of the wind tunnel experiment show that the wind pressure is mostly negative on the single-layer Geiger lattice shell with curved plate.But under the 90° wind direction,because of the flow obstruction of the front building,the positive pressure appears on some area of the roof’s edge.The wind-induced response analysis results show that many modes make contribution to the structural wind-induced response,and the higher modes should be considered.Subjected to the fluctuating wind load,the mode coupling should be considered in order to obtain a good accuracy of the wind-induced response for all the structural nodes.If only the accuracy of the larger displacement is needed,the square root sum of square(SRSS) method which ignores the mode coupling can be also used.It is found that both the load-response correlation(LRC) with inertia force method and the modified LRC method for calculating the equivalent static wind load of the single-layer Geiger lattice shell with curved plate can ensure the equivalence of the largest displacements rather than all the nodal displacements.