卡门涡街作用对钢管避雷针机械强度的影响

The Effect on Karman Vortex Street to the Mechanical Strength of the Lightning Rod of Steel Tube

通过两起架构钢管避雷针的断裂跌落事故提出了目前避雷针设计时忽略的一个因素,这个因素就是流体对避雷针作用的卡门涡街现象。接着介绍了卡门涡街的概念和卡门涡街作用形成涡激共振的条件,并通过一个故障避雷针进行涡激共振疲劳寿命计算,最后对750 kV和330 kV钢管架构避雷针的一阶共振临界风速和二阶共振临界风速进行了估算,并且,给出了避免发生涡激产生的改进措施:通过对避雷针气动控制措施的改善来避免涡激共振的产生。

A factor easy to be ignored when the lightning rod design was put forward through two structure steel rods fracture fall accident, the factor is phenomena of karman vortex street of fluid to lightning rod. Then the concept of karman vortex street and the condition under which the vortex- induced resonance is formed by the karman vortex street are introduced, and vortex-induced resonance fatigue life calculation is carried out through a fault lightning rod, finally, the first order resonance critical wind speed and second order resonance critical wind speed of the 750 kV and 330 kV structure steel rods are estimated, and the improvement measures to avoid the generate of the vortex-induced is provided： the generate of the vortex-induced resonance is avoided through improving the lightning rod pneumatic control measures.