基于显示积分法的大跨越输电高塔风致振动响应研究

Random Wind-Induced Dynamic Response of Long-Span Transmission Tower By Improved Explicit Integration Method

输电塔属于风敏感结构,风与结构的相互作用十分复杂,风荷载常常是设计的主要控制荷载。本文以某一高185 m的500 kV输电跨越塔结构为工程背景,建立了详细的有限元计算模型,获得了结构的自振动力特性。在考虑节点风荷载空间相关性的基础上,利用Kaimal谱对结构的风荷载进行了准确的数值模拟。结合改进显示积分法的优点,计算得到了结构的风致振动响应时程。研究了结构位移平均值、位移均方根值和加速度均方根值的分布特点,同时分析了结构各层的荷载风振系数和位移风振系数,并与多种规范进行了对比。通过研究,揭示了超高输电铁塔的风致振动特性,结果可作为输电塔结构抗风设计的参考。

With the complex interaction between wind and structure,transmission tower belongs to wind-sensitive struc- tures and the wind load becomes the main problem of the structure design. Based on the engineering background of a 185 m high 500 kV transmission tower, a precise finite element model was established and the vibration characteristics of structure have been obtained. The time history of fluctuating wind load was accurately simulated by considering the spa- tial correlation of Kaimal wind spectrum. With the advantages of improved explicit integration method,the wind-induced vibration responses of transmission tower were obtained in the time domain. The characteristics of Mean displacement Rms displacement and Rms acceleration at different layer of transmission tower have been analyzed in a detailed. Mean- while ,the wind-induced vibration coefficient at different layer of transmission tower were also studied and compared, re- spectively. Through research, some characteristics of wind-induced vibration of transmission tower were revealed and the procedure and the results presented in this paper can be used as reference for the design of transmission tower.