双曲面钢桁架冷却塔风致效应参数研究  

Parametric study on wind-induced effect of a cooling tower with hyperbolic steel trusses

作　　者：陈讷郁 陈旭 赵林[1] 葛耀君[1] CHEN Neyu, CHEN Xu, ZHAO Lin, GE Yaojun(State Key Lab of Disaster Reduction in Civil Engineer, Tongji University, Shanghai 200092, Chin)

机构地区：[1]同济大学土木工程防灾国家重点实验室

出　　处：《建筑结构学报》2018年第4期18-27,共10页Journal of Building Structures

基　　金：科技部国家重点基础研究计划(973计划,2013CB036300);国家自然科学基金项目(51323013,51678451,51222809)

摘　　要：为研究钢结构冷却塔的抗风性能,以某超大型空间双曲面钢桁架冷却塔待建工程为研究对象,依据风洞试验实测了脉动风荷载数据,利用POD算法生成作用在冷却塔有限元计算模型上的风压时程,通过瞬态动力分析得到冷却塔位移响应,对比不同位置振动频率参与情况,获得了位移风振系数分布结果,并比较了结构阻尼比和质量分布对冷却塔风致行为的影响。研究结果表明：钢结构冷却塔1-4阶固有模态风振位移占主导地位,其中,位移风振系数沿环向在迎风侧（0°-40°）取值较小,介于1.70-2.12;在侧风向（40°-180°）取值较大,介于1.97-3.01;沿子午向位移风振系数随高度的增加而增大。结构总体风振系数随着阻尼比增量呈现递减趋势,随质量增量呈现递增趋势,位移风振系数分布形态相对固定。The wind-induced dynamic performance of a super large cooling tower with spatial hyperbolic steel trusses was investigated. The structural responses of the cooling tower under stochastic wind loadings were calculated in time- domain using measured surface wind pressure in the wind tunnel. The refined time histories of the wind pressure distributed on the finite element nodes were interpolated by the POD algorithm based on the measured data of fluctuant wind loading. The displacement response could be obtained by considering complex spatial wind pressure excitation, based on which wind vibration factors were obtained. A parametric analysis, considering the effects of participation ratio of vibration frequency, damping ratio and mass, were discussed systematically. The results show that one to four order intrinsic modes dominate the resonant displacement. The wind vibration factors （ between 1.70 to 2. 12 ） in windward area （0~ -40~） are smaller than those （between 1.97 to 3.01 ） in lateral and leeward areas （40~ ~ 180~） along the circular direction. The wind vibration factors along the vertical condition increase with increase in height. The wind vibration factor decreases with increase in damping ratio, and increases with increase in mass. The distribution of displacement gust loading factor is generally consistent.

关 键 词：钢桁架冷却塔 风洞试验 POD分析 风振系数 

分 类 号：TU279.741[建筑科学—建筑设计及理论]