输电塔动力特性计算与模态试验研究

Calculation and Modal Testing of Dynamic Characteristics of Transmission Towers

输电塔是国家电网的重要组成部分,具有结构高、跨度大、柔性强等特点,对风荷载反应灵敏。建立能反映输电塔动态特性的模型对风致振动控制至关重要。为研究输电塔理论模型的准确程度,分别建立3种输电塔实验模型,包括多质点模型、梁单元有限元模型和梁-杆混合单元有限元模型,并对其进行模态分析;同时采用锤击法,以单点激励多点响应(SIMO)的测试方法对输电塔实验模型进行模态测试。将各方案与测试结果进行比较分析,结果表明:梁-杆混合模型的求解精度高于另外两种计算模型的精度,能较好模拟输电塔的动力特性,是最优的输电塔模拟方案。

Transmission towers are the important parts of the state grids. They have the characteristics of high structure, large span, flexibility and sensitivity to wind loads. So, it is important to establish a model which can reflect these dynamic characteristics of the transmission towers for wind-induced vibration control. In this study, three kinds of experimental transmission tower models are established, including multi-DOF model, finite beam-element model and finite beam-rod mixed element model to testify the accuracy of the theoretical models. Modal analysis is carried out subsequently.Meanwhile, a hammering test based on Single-Input Multi-Output(SIMO) method is performed on the experimental transmission tower models. The computation results are compared with the test results. It is shown that the model using beam-rod mixed elements is the most accurate simulation model of the three. It can excellently simulate the dynamic characteristics of transmission towers. This model can be regarded as the optimal model for the transmission tower simulation.