沿海地区避雷塔静动特性与稳定性分析

Study on Static/Dynamic Characteristics and Wind-Resistant Stability of Lightning Tower in Coastal Area

针对沿海地区受台风影响避雷塔发生倒覆的问题,利用有限元方法对某42m避雷塔和42m拉线避雷塔进行静动特性与稳定性分析.对避雷塔结构进行了模态分析,计算避雷塔受风载荷,通过风载荷APDL程序,对避雷塔所有构件施加风载荷,计算结果表明,拉线避雷塔结构的最大应力较避雷塔结构下降了63.1%,且满足强度要求.采用AR模型模拟脉动风,脉动风响应计算结果显示,拉线避雷塔结构最大位移响应值为避雷塔结构的3.9%～5.6%,增设钢丝绳可以有效减小避雷塔受脉动风振动的幅值.采用非线性屈曲方法对两种结构进行屈曲分析,结果显示拉线避雷塔和避雷塔结构的临界屈曲风速分别为76.3m/s,42.5m/s,前者较后者高79.5%,满足抗风稳定性要求.

Aiming at the tower-collapsing accidents caused by typhoon in coastal areas,the static and dynamic characteristics and wind-resistant stability of a 42-meter-high lightning tower and 42-meter-high cable stayed lightning tower were analyzed by means of finite element method.Modal analysis was performed on the lightning tower and the wind loads of the tower were calculated.Using APDL programs,the wind loads were applied to all structure components;the calculation results show that the maximum stress of the cable stayed lightning tower decreases by 63.1%than the lightning tower and the strength of the structures can meet the requirements.AR model has been used to simulate fluctuating wind.The results of fluctuating wind response show that the maximum displacements of the improved structure are 3.9%～5.6% of the lightning tower,and adding wire ropes effectively reduce the amplitude of the vibration.Besides,using the nonlinear buckling analysis method,buckling analysis is conducted and it show that the buckling critical wind speed of the lightning tower and the cable stayed lightning tower is 42.5 m/s and 76.25 m/s respectively.The former is 79.5% higher than the latter.The results indicate that the stability of cable stayed lightning tower can meet the requirements.