三维湍流风场中雨滴竖向运动特性及FAST索网结构风雨振响应研究  

Characteristics of vertical motion of raindrops in a three-dimensional turbulent wind field and response of rain-wind induced vibration of cable-net structural system of FAST

作　　者：王成宇 李宏男[1] 付兴[1] 李庆伟[2] WANG Chengyu;LI Hongnan;FU Xing;LI Qingwei(School of Infrastructure Engineering,Dalian University of Technology,Dalian 116024,China;National Astronomical Observatories,Chinese Academy of Sciences,Beijing 100101,China)

机构地区：[1]大连理工大学建设工程学院,辽宁大连116024 [2]中国科学院国家天文台,北京100101

出　　处：《建筑结构学报》2024年第10期144-157,共14页Journal of Building Structures

基　　金：国家自然科学基金项目(52027811,11973006)。

摘　　要：为了揭示大跨度空间结构在风雨耦合作用下的动力响应特征,研究了三维湍流风场中雨滴竖向速度的变化规律。推导了单雨滴在三维湍流风场中的运动方程,分析雨滴运动轨迹和竖向降落速度。引入了雨滴竖向速度比的概念,并通过构建雨压概率的分布,得到一定置信度下的竖向速度比建议值。基于多元非线性回归分析建立了竖向速度比建议值拟合式,确定雨滴竖向速度的计算方法。考虑雨滴与结构的正面、背面两表面发生碰撞,建立了适用于一般结构的雨荷载计算模型,并开展了FAST索网结构在风雨联合作用下的响应研究。结果表明:在三维湍流风场中,雨滴的运动行为表现出复杂的非线性特性,且雨滴竖向末速度和经验竖向末速度不再保持一致;在风雨耦合作用下,由雨荷载引起的FAST索网节点平动位移均值占总均值的39.7%,说明雨荷载对大跨度空间柔性结构的动力响应有较大影响。为此,在结构设计中,风雨联合作用对大跨度空间柔性结构的影响不容忽视。To reveal the dynamic response characteristics of large-span spatial structures under the co-effect of wind and rain,the vertical velocity variations of raindrops in a three-dimensional turbulent wind field were investigated in this paper.The motion equations of each raindrop were derived in a three-dimensional turbulent wind field,which could reveal their falling trajectories and velocities results.Besides,the concept of vertical velocity ratio of raindrops was introduced,and the recommended ratio values at a certain level of confidence were obtained through the construction of rain pressure probability distribution.Multivariate nonlinear regression analysis was applied to establishing a fitting formula of recommended value of vertical velocity ratio and calculation for the vertical velocity of raindrops was confirmed.Finally,given that both the positive and negative surfaces of general structures could collide with raindrops,a calculation model of rain load for general structures was established,and the response of the cable-net structural system of FAST to the co-effect of wind and rain was investigated.The results show that the raindrops exhibit complex and nonlinear motion characteristics in a three-dimensional turbulent wind field,and the vertical terminal velocity of raindrops is not consistent with empirical vertical terminal velocity any more.Under the co-effect of wind and rain,the average translational displacement of the FAST cable network nodes,which is induced by rain loads,reaches 39.7%of the total average,illustrating a large impact of rain loads on the dynamic response of large-span spatial flexible structures.The study concludes that the co-ffect of wind and rain on the large-span spatial flexible structures cannot be neglected in structural design.

关 键 词：FAST索网结构 三维湍流风场 风驱雨 雨滴竖向末速度 雨荷载 

分 类 号：TU399[建筑科学—结构工程] TU312