摘要
山地风场因受山体的干扰作用具有与平地风场截然不同的特征,对山地地形中结构高、跨度大和电压等级高的特高压输电塔线体系进行风振响应研究时,无法采用现有适用于平地风场的计算方法。为此,在风洞试验的基础上,首先对三类山地地形的不同工况,即单个山体的8种坡度,单个山体的3种高度以及两个山体的3种遮挡间距,对风场的影响分别进行了研究。通过对各工况下山体迎风面、山顶和背风面的平均风速加速比及湍流度的变化情况进行分析,提出了相应的修正公式,有效地考虑山地地形对风场的影响,得到了各工况下山地风场的平均特性和脉动特性。然后,基于试验数据及风场模型采用有限元计算理论对特高压输电塔线体系在各工况的风场条件下进行动力时程分析,并根据随机结构动力可靠度计算方法分别计算出各工况下特高压输电塔体的动力可靠度。最后,通过对比分析发现了不同山地地形条件下各工况中迎风面、山顶及背风面的不同位置输电塔体动力可靠度的变化规律。
Currently,calculation methods of a general transmission tower are not suitable to a ultra-high voltage（UHV） transmission tower with large height and large span.Further more,the characteristics of a hilly terrain wind field are distinct from those of a flat terrain wind field due to the interference of hills.Here,three hilly terrains were studied with wind tunnel tests.The effects of varying of hilly conditions were considered,such as,8 different slopes,3 different heights and 3 kinds of occlusion distances between two hills.Then,the modified formula of topographic effects was proposed after studying the variations of the average wind speed and the fluctuating wind speed of the 3 hilly terrains models.Based on the test data and the proposed models of hilly terrain,the dynamic responses of UHV transmission tower-line coupled system in different hilly terrains were calculated with the finite element method.With the dynamic responses of the UHV transmission tower-line coupled system,the dynamic reliabilities of the transmission tower were calculated with the stochastic structure＇s dynamic reliability method under different working conditions,respectively.At last,the dynamic reliability variations under windward,forward and crest of three hilly terrains were obtained.
出处
《振动与冲击》
EI
CSCD
北大核心
2012年第20期1-6,31,共7页
Journal of Vibration and Shock
基金
国家自然科学基金资助项目(50908243
51078367)
关键词
山地风场
特高压输电塔
动力可靠度
加速比
湍流度
hilly terrain wind field
UHV transmission tower
dynamic reliability
speed-up ratio
turbulence intensity
作者简介
第一作者李正良男，博士，教授，博士生导师，1963年5月生
